(1) Those nasty things inside car batteries are easily recycled and in fact are recycled more often than not (like 95%+)
(2) Car batteries do not last only 3-4 years as per the OP. Car batteries can last decades. There are many variables, but the car in my battery is far older than 4 years. (lol)
(3) Replacing an easily-recyclable product with a less-recyclable one is no step forwards.
(4) XX addressed by OP comment, see below XX
This thing is a capacitor? What's the voltage potential in there? Any device with internals significantly beyond that may be a serious fire risk in a crash..
(5) Car batteries are not needlessly heavy, nor are they a stock size. Manufacturers do care about performance. If they thought the car could do with lighter battery they would use one. Have some respect for the thought behind stock engineering before replacing it.
(6) Shutting down the voltage supply can be a real pain. A "dead" battery generally still has enough juice to keep electronics ticking over. Cutting it completely is not like turning off a switch. It often means resetting/rebooting stuff once the voltage is restored. For some (BMW) it can even mean a trip to the dealership for a special new battery ritual.
http://www.bimmerforums.com/forum/showthread.php?1355106-Why...
You're right! Lead acid car batteries are one of the great recycling success stories. What's interesting is that the volume of lead acid car batteries in the world is so high, that even at that high recycling rate, that still leaves 24 million pounds of lead each year from car batteries that don't get recycled. There's also been some problems recently with lead recycling plants contaminating the environment [1].
You're also right that it's more complicated to recycle lead than lithium batteries, but a recycling process does exist, and it's getting better thanks to the proliferation of lithium batteries in electric cars.
It's actually got 6 capacitors in series (2.7V each). We don't charge them all the way up to 2.7V, so it's normally at about 13V on the terminals. We are super paranoid about safety. The EDLC caps we picked aren't a fire risk, since it's just carbon and a few mL of electrolyte. You're probably thinking of what electrolytic caps do when you reverse bias them, but EDLC caps are much nicer. The worst they'll do is vent the electrolyte, not explode. LiFePO4 batteries are also really stable and are used in electric vehicles all the time.
> that still leaves 24 million pounds of lead each year from car batteries that don't get recycled
Is that actually a lot? Similar statements are made with respect to nuclear waste, but frankly, I've regarded these statements in units of mass as deliberately misleading due to nuclear waste (or lead in this case) to be uniquely dense relative to what we are accustomed to dealing with on a daily basis.
Siri, via Wolfram Alpha, says that 24 million pounds of lead is about 33,900-ft3, or a cube of 32-ft a side. If correct, that doesn't feel like a lot considering this is framed as a the global lead acid car battery recycling waste.
Lead is also pretty bad for people. From some research on Wikipedia and with GNU units, an adult can get clinically significant lead poisoning by absorbing about half a milligram of lead into their bloodstream. (You would have to eat, breathe, or touch more than that in order to get it into the blood.)
If you took all of that non-recycled car battery lead waste and distributed it evenly across the whole U.S. population, you would have 6 orders of magnitude more than the absorbed dose required to give everyone in the country clinical lead poisoning.
(Obviously most of that waste has no likelihood of being absorbed into someone's body, so this calculation isn't necessarily that meaningful.)
Olympic sized pool = 164ft x 82ft x 9ft 10 inches = 132, 300ft^3. Density of lead: 709 lbs per ft^3.
So a single Olympic-sized pool would weight almost 94,000,000 lbs if filled with lead.
(If you really want to blow your mind, that same pool would weight almost 200 million lbs if filled with Osmium, the most dense element. Of course, that's WAY WAY more than the amount of Osmium that exists...I can't find a world wide figure but US production is only about 250 lbs per year)
I have always been surprised how cheap osmium is given how rare it is ($400 an oz). I have wanted to buy some, but it is not the nicest metal to play with [1].
This might be an unpopular view here but I think artificially increasing core charge fee via laws could easily bring that recycling percentage to 99%. Could you imagine if you did not hand in your old battery when buying a new one it cost an extra $300 instead of $20 or so like now? A token portion of that could be used to fund state inspections of recycling facilities.
The whole dismantler/recycling system in place for automobiles is really something quite impressively successful. Having so many places to pull used parts to keep other cars going lessens environmental burden multiple fold. Battery recycling is probably the biggest triumph of them all though.
Valid concern: it means every possible application of a car battery, if the $300 fee is to be avoided, must involve purchasing a product that already contains a battery. Bad news for DIY makers that need one: they'd need to find a containing product rather than purchasing a battery alone, which might make for a market where fake containing products (to be completely discarded aside from the battery) exist to fill the gap, thus rendering the whole model broken. Is there a solution?
That's a good point. For me though I have had plenty of cars that only last a few months before I drag them to the junk yard. I've used lots of parts from them for cores to offset the cost of rebuilt parts I need to keep another of my cars going. I've also borrowed the car battery from a running car that I'm not using much for art and audio projects. Considering how much some of them had cost another $300 would not have mattered much.
Glad to see you are on top of the voltage/fire thing. But I still see these things as non-recyclable in comparison to industry-standard lead-acid batteries. I can drop my current battery off at any number of garages without issue. Once this new device inevitably breaks down (anything under a hood will eventually) it seems like just more e-waste.
Yeah, we're still figuring out the best way to handle collecting the units at the end of life, but there's already places like this that we can send them to and keep it from turning into e-waste: http://www.kinsbursky.com/
You might want to add language re battery orientation. It looks like your device doesn't care about up and down. That's a big deal for car people. They pay extra for a 'dry' battery that can be mounted in weird places and angles. And mention venting or lack thereof. That's another sticking point for people shopping for aftermarket batteries.
Also, vibration testing if you have done any. Custom cars and offroad machines shake. Nobody wants a battery with internals that look like they might break loose.
If you really want to sell a premium battery, create a motorcycle model. Sportbike owners are really into weight reductions and eat through batteries. It might as simple as a smaller plastic shell.
Sportbike owners are already buying cheap LiFePO4 batteries sans capacitors in droves, so there'd have to be some kind of strong differentiation for Ohm.
I've also used one to run my Elise (2ZZ 1.8L 4-cylinder) for a few years now without issue.
The three major issues I've heard about are are longevity, price, and reserve capacity. Cold weather is a bit of an issue, but strangely it's actually made better by more load as the battery's internal resistance eventually heats it up to the point that it works fine.
I really don't get this product yet. Unless the supercapacitor provides an incredible enhancement in longevity (maybe it does, but my understanding and experience is that temperature and poor manufacturing are the main enemies to these batteries, not instantaneous load), I'm not sold on buying one instead of one of the inexpensive existing alternatives.
The supercaps provide a huge enhancement in longevity, since the maximum current draw from the battery is lower. This can even mean a difference in manufacturing for the battery in some cases, as there are design tradeoffs between peak current draw and lifetime.
It's also potentially lower weight and lower cost, since you won't need as large of a battery (EDLCs aren't cheap though, so there is a limit).
I run these on three Ducatis, including my track bike - http://earthxmotorsports.com Amazing batteries!! Super light, and super powerful. All the bikes start up faster/easier even after sitting all winter.
I wonder if an argument could be made for audio systems. Very "peaky" power draws from sub systems already have some people putting caps in parallel with their batteries (to mixed success).
If your device had an equal market share, what fraction of it would be recycled? What core charge would a new buyer be expected to pay for that recycling cost?
It will probably take a few years to get certified, but take a look at what goes for $600 as a flooded-cell battery in general aviation. The fact that you use LiFePO cells will probably help, as there is no way a LiPo would ever get approved.
Yes, those were lithium cobalt IIRC. LiFePO were new technology when the 787 was designed (it's a long product cycle) and the FAA required a metal shield around the LiIon batteries.
LiFePO is much less likely to enter thermal runaway, and much less explosive when it does. Overcharging them is about as bad as non lithium chemistries (it's even possible to start a fire by overcharging a lead-acid). Don't try this at home, but overcharging and shorting a LiFePO isn't nearly as catastrophic as doing so with a LiCoO or LiPo. With those chemistries you're basically relying on the battery firmware to keep the battery from exploding under those conditions.
The price point is impressive if you can sell at only ~$50 more than a standard lead-acid battery. If pressed to find a flaw, I think the biggest is one you've already identified:
There’s one: you can’t run your lights and/or stereo as
long with your engine turned off. Ohm’s battery reserve
comes in at 10 amp hours; most lead-acid car batteries
come in at about 45 amp hours. If you can run your
stereo with your engine off for three hours on your
current battery, you’d be able to run it on Ohm for less
than an hour.
Nobody with a modern car or SUV is going to get three hours' runtime for their accessory equipment. With the original equipment (AGM lead acid, 70 AH/450 CCA) battery in my two-seat passenger car, I'm lucky to get 15 minutes' worth of stereo/nav/etc. operation with the ignition off. There's no conceivable way that 10 AH is enough for this application. The more "luxurious" the car, and the newer it is, the worse this problem will be. Meanwhile, LiFePO4 battery cost will probably go in the opposite direction, leaving room for competitors to offer more power for less money.
So I'd reconsider the size of the LiFePO4 battery, even if it makes the product cost a bit more. You need those high-end buyers. You're not going to sell these to Joe Sixpack for installation in his '98 F-150 pickup.
And yes, your marketing materials are grossly exaggerating both the environmental problems with lead-acid batteries and their typical service life. There is clearly a global regulatory jihad against lead in all of its forms and uses, though, so you do have that going for you.
Edit: Don't forget that auto stop/start is growing in popularity as well. I think it's actually mandatory in some (European?) markets. OEMs are moving toward "smarter" (read: DRM-locked) batteries to handle these additional requirements. I wonder if a better business model might be to offer recycling/rebuilding services that swap out lead plates for LiFePO4/supercap hardware in existing batteries?
>Nobody with a modern car or SUV is going to get three hours' runtime for their accessory equipment.
Really? I've left the satellite radio playing for hours in my 2011 Hyundai Sonata at moderate volume with no hint of problem starting my car afterwards. It has the premium sound system (including subwoofer) and navigation.
There are always going to be anecdotes to the contrary, but the trend is pretty clearly in the opposite direction.
Usually what happens in my case is I forget to turn the headlights from 'Auto' to 'Off.' But even with the lights and fans off I don't tend to see more than 20-30 minutes of operation at most. The car's version of HAL 9000 tries to be conservative and shut things down as soon as the battery voltage goes below about 11.9.
Don't know about US, but many new cars in EU ship with LED headlights(and no, I don't mean daily running lights, I mean the actual headlights) - for example the new Nissan Qashqai. In US it's sold as Nissan Rogue.
No, that's a repeatable observation. There's a difference.
Look, take it up with Volkswagen AG. They're the ones who designed the electrical system in the car in question. Don't shoot the messenger, but a long term business plan centered around aftermarket car batteries is going to be a challenging play, for these and other reasons.
> Also F150 pickup trucks are about $60K when loaded with options.
If you buy new. The parent commenter specifically mentioned a '98 F150.
Personally, though, I'm interested in one of these for my Blazer for the cold-temperature performance alone. If the lower power capacity is an issue, I could always just carry around my jumpbox.
That's not how it works. By design, there is still plenty of capacity left in the battery when the car's computer shuts down the accessories.
The accessory draw is enough to lower the (indicated) terminal voltage from about 12.6 volts to about 12.0 in 15-30 minutes, depending on what accessories are actually turned on.
I can't emphasize how wrong you are about the whole "you can only get 15 minutes of radio off a car battery".
Your battery is broken or you have a near-short somewhere. I sit in my cheap-ass Jeep for 45 minutes a week listening to the radio for 5 times a week and have for years. Replace it, if it doesn't work seek professional repair.
Amusingly, I also have a cheap-ass Jeep, and gee, you're right, it has no problem running the radio for at least an hour with the ignition off.
So if you think this is a sustainable, scalable state of affairs, at a time when automotive tech is undergoing its greatest disruption since the horse, we'll leave the discussion at that. I'll just say that I think this is a really bad time to aim their business plan at a fixed target, and one that I'm not sure they actually understand.
I wasn't putting a dog in this race with that comment, just urging you to get that battery checked up on before it dumped you at the side of the road. Headlights pull some wattage, but a radio really shouldn't and there's no way 15 minutes should cause any concerning symptoms. Just trying to help :)
I'm not sure how I feel about it, personally. I share a lot of the concerns that have been raised here (battery cutout wiping my clock+radio, vibration, longevity, cranking+jumping ability, etc), and I'm always a bit wary of "One Weird Trick; Auto Companies Hate Him!" claims. I'm certainly not going to be the test dummy for that one, I got places to be that aren't the side of the road. Give me 5 years of early adopters and we'll see.
Neither here nor there, but I was one of the early adopters of electric motors in R/C airplanes. I was doing it since before brushless was a thing (about 15 years), my first plane used a brushed Graupner car motor and Sub-C car packs (boy howdy was that underpowered). I can tell you that batteries have a very finite lifetime, especially when you abuse them under high-current loads. I worry that a lot of hybrid/electric owners are in for some sticker shock when their packs wear out. That one unit is a pretty significant fraction of the total cost and it's a wear item. I know there's steps taken to lengthen the life of the pack, but you can't run them indefinitely.
If you look at this purely from the standpoint of the benefit to a consumer, it doesn't seem like a great deal.
You gain:
* Auto-shutoff when your battery gets too low.
* Possibly some increased lifespan
* ~34lbs in weight reduction, which might deliver a small performance increase.
You lose:
* 78% of your battery capacity
* $20-$150 on the purchase price of the battery
Personally, I don't like the idea of paying more money for less battery capacity. If, however, Ohm came with a rock-solid 7-year replacement warranty, I might be able to get over that.
Suppose they did offer a 7-year warranty, with strong language. Would you really expect Ohm to be around in 7 years? If they want people to take a warranty seriously, it needs to be backed by at least an A-rated insurer, not whoever is funding these guys.
There's also the problem that they apparently offer only a single size/form factor (which is roughly equivalent to 34, 34/78, 75/25, or 35), and that for many applications this device does not offer enough starting power. Never mind reserve capacity. But even if this size is appropriate to your car, there are other reasons to be skeptical.
I guess the pitch is that you do not need the extra battery capacity?
Are you sitting in parking lots listening music these days? That did sound cool when you were kid, but majority will never do that (or take their car camping).
And even if I did take my car camping, I probably wouldn't be using its electricity except in extreme circumstances; I'd sooner bring - at the absolute most - a separate generator (preferably one of those quiet Honda ones) if I really feel the need to be plugged in (which is rarely the case; the point of camping for me is to get a breather from tech).
If, however, Ohm came with a rock-solid 7-year replacement warranty, I might be able to get over that.
That's a good idea, and they could even make it a lifetime warranty (lifetime of the car, that is). "Ohm: The last battery your car will ever need" could make a nice tagline.
In the fine print, the implementation would be a replacement guarantee for as long as the customer owns their car. Since most people don't keep the same car for 7 years, it would be a safer bet than a fixed 7-year guarantee.
My impression was that said smarts are possible in the Ohm because of the otherwise-wasted space caused by the smaller internals.
On the other hand, if there's that much more space, I'm curious as to why some more battery or capacitor banks couldn't be added to address the low-capacity concerns.
You could probably even do it as an add-on to batteries, although now I'm wondering why it isn't built into the cars themselves. They could easily do it.
> I leave my lights on and kill my battery once every few months, so this is easily worth it for me
I compulsively check to make sure my lights are turned off yet my battery still dies at least once a year because I don't regularly use my car, costing around $200 in on-site service and replacement per go. The smart shut-off feature is worth it to me - even if it's just to save time waiting around for someone to perform a replacement. The reduction in weight is a bonus as I have a small car with a fairly humble engine displacement.
One of the best tools I ever bought was a 6 amp battery charger. Plug it in, and in 20-30 minutes the battery has enough charge to start the engine, then you're good to go.
This has saved me many, many hundreds of dollars, being late for work, etc.
I also have a battery maintainer that keeps a battery sitting around charged up.
The last thing is a battery shut-off switch that sits on the battery terminal. If you're going to leave the car a while, shut it off. It prevents the trickle going to keep the radio alive from killing the battery (which takes a week or two).
When I bought my Civic Type-R it didn't even have an option for air conditioning due to the weight it added. For some types of car every pound (though they are called grams in the real world) counts. I suspect this will be popular in the lightweight performance car world.
For sure losing 30+lbs is a big deal in the high-performance automotive world, and Ohm's price premium is nothing compared to, say, replacing structural elements with carbon fiber etc.
But I don't think your average mass-market consumer is going to care much about 30lbs, or notice a difference in performance or handling if they did.
> But I don't think your average mass-market consumer is going to care much about 30lbs, or notice a difference in performance or handling if they did.
In reality, if you looked through the car of a random sample of the population, you'd probably find about 30lbs of crap in their car that they could remove (sporting equipment, rubbish, bags, etc).
I'm not sure why my comment got so downvoted, that's kind of weird as I was just stating facts.
Absolutely the average buyer of a Camry is not going to care about this. But that wasn't at all my point. Some cars (more often in Europe/Japan where driving is more fun because they have corners), take weight seriously. I think car manufacturers might take this option seriously in their sport divisions.
Probably because of the "in the real world they're called 'grams'" remark. I vastly prefer metric over Imperial, too, but that came across as a tad snobbish, eh?
I upvoted, though, for what it's worth; weight savings aren't just the purview of racecars.
I don't get your (4). It's a capacitor + lithium battery. It's got to be nominally 12 volts, or else it wouldn't work in a car. Capacitors only charge to the voltage you apply -- in this case, 12v. I'm not sure if you mean voltage by "beyond that", but fire risk isn't really correlated with voltage - more with chemistry, energy, and fusing.
I was thinking about the internals. They might have components with higher potentials that are then regulated down to 12v. In a crash, those could be a source of high-voltage shorts that might be a source of ignition.
No worries there. Everything is right around the 12V level. We can boost the voltage on the capacitors some, but we never exceed anything that the alternator is spitting out.
Oh, one other thing I wanted to add: The 3-4 year lifetime of lead acid batteries is the average lifetime. There are certainly outliers, but if you go to the store and buy a lead acid today, the warranty is about 3 years.
The BMW thing is interesting. The reason they do that little "ritual" is because they want to program the ECU to use a particular charging profile for your battery, and it needs to know the age of the battery and the type (AGM or not). That's to try to extend the lifetime of the battery. We don't really need to worry about that, since we handle all the charging profiles internally. One of our testers drives a BMW, so we're making sure that we can handle that and similar cases.
You're right about the life. Who here has replaced a car battery after 3 years? My '89 Miata had the OEM battery (an AGM lead-acid battery), 25 years later.
Indeed. I wonder if Ohm works the same way, in that if you have an optimal driving pattern it will last you for 20 years. I suspect based on the Li-ion batteries in laptops and how poorly they last that the Ohm will have a much more predictable failure curve.
If you live somewhere hot, it can be rare to get even 5 years out of a battery (although if you buy ones with a 3 year warranty you may only be paying for a battery every 5 years or so)
With regards to 5, my understanding is that car batteries are as big as they are because of the need to have over-capacity for reliability. Lead acid batteries are actually kind of fragile in the grand scheme of things. Charge controller smarts can trump over-capacity in the right context, however.
While I agree with points 1 and 2, I have a beef with point 5. Car manufacturers do whatever they can to shave costs, all over the car, all the time. Batteries are needlessly heavy because they are manufactured with the cheapest-possible components using the cheapest-possible technologies. They do put in a best-guess size to keep the median consumer masses happy, whether they drive the car once a month in Death Valley or six times a day in Duluth.
You can buy lighter-weight, lower-capacity batteries to use in competitions where weight matters, or higher-technology batteries for use in angles where lead-acid will give up the ghost. Batteries are frequently moved by tuners to places where their weight has less of an affect on the car's suspension.
That's not really true any more. Due to increasingly strict fuel economy rules, every car manufacturer now has cost models to trade off weight versus cost and reliability. So they will pay a little more for lighter parts.
> (2) Car batteries do not last only 3-4 years as per the OP. Car batteries can last decades. There are many variables, but the car in my battery is far older than 4 years. (lol)
I have a 2003 VW GTi. Had the battery replaced for the first time late last year. The AAA Tech was surprised that I had over 10 years of use with the stock battery.
Not really, BMWs have a battery management system that needs to be cleared of the learned calibration when the battery is replaced. If it's just disconnected and not replaced then you don't want to clear it. Also, if that were true it would make doing any work a terrible experience even for the dealerships. Heck the service manual probably says to disconnect the negative battery cable before changing windshield wipers.
(7) This doesn't apply to all performance cars, but in track racing where you really need to save every possible ounce, it's common to take the battery out altogether after starting the car and run it off the alternator.
Co-founder here. Do the cars you're talking about use a distributor? The battery of a car works as a low pass filter for the alternator, and removing it entirely can cause huge spikes in the voltage it puts out. That can be destructive to just about any electronics it would be running. I've personally seen an accidental battery disconnect blow an ECU.
It's crazy how applicable the Presumption of Stupidity article that was posted a couple of days ago has been. Your comment is basically a re-hashing of that post.
We presume stupidity because that's the default state of a person. You have to load instructions and data into a neuroprocessor, just like any other computer system.
Modern cars with keyless entry typically draw ~50mA@12V when "off", this power is used to power the receiver, keep ECU state for such things as learned fuel maps, blink the alarm-on indicator, etc. 45Ah capacity gets you a bit over a month to drain down the battery, while 10Ah gets you a bit over a week. This isn't good, you'd have to keep it on a battery tender if you're not driving the car for just a week.
I can also see how one would implement a low voltage cutoff to prevent running down the battery, but then, how in the world do you automatically re-engage the battery to allow starting the car? You've shut off the power to the whole car, so you no longer have a circuit to monitor. If you're allowing some amount of current to trickle out, you must, by definition, be allowing the voltage to sag, which can run the ECU or alarm out of spec, causing havoc.
As the battery designer, your only input to make these decisions is the resistance of the car's electrical system.
The only thing you control is your own internal resistance.
Co-founder here: The capacity isn't set in stone. You might be right, if we need to increase it we can - or just offer a couple different options, but so far we haven't seen any issues and a number of our beta users are only using their cars once every few weeks.
The capacity quoted on lead-acid is also a bit deceptive. There amount of current you can draw drops pretty heavily with state-of-charge. You might have trouble starting your car even with 50% of charge left. So if Ohm doesn't work for you, you'd likely be having trouble with a lead-acid as well.
As far as the low-voltage cutout - it's definitely not trivial, but it's been done in other applications previously. I'd be a bit ashamed if you were able to come up with a solution of the cuff though, it took us a lot of work to get it working! It does involve some energy injection, but not enough to cause problems.
You can periodically pulse the circuit at a low voltage and figure out the resistance, and if the voltage is low enough, you won't power anything up. When the ignition goes into the ON position, you've got a huge drop in resistance as fuel pump, and other necessary electronics get enabled. A sudden drop in resistance is a good signal that you should turn the power back on. This will not work with some more recent electronic systems, but should work great for most mechanical ones. Pretty sure you haven't solved things like the interaction with a BMW battery monitoring computer, for example, and those cars will probably reject your battery with some crazy error after a while.
It's good that you've got space for more reserve capacity, parasitic drag is getting higher as cars get more fancy. For example, radiator fans and turbo oil circulators can run for quite a while after the engine is off.
Your super capacitor design is elegant - you can charge the supercap off the battery slowly, even at low state of charge where its voltage would sag too low for the starter relay if you were directly using the battery.
I have a little car which I race and weight matters, so I've been using a ~12Ah LiFePO4 home-made battery for a while (A123 cells). This is a very durable little battery chemistry. No fancy super-caps, though, I just keep mine topped off and starting the car puts the battery cells close to their maximum discharge current.
I wish you guys the best of luck. Lead acids are pointless with modern battery technology.
Lead acid is traditionally very forgiving with regards to temperature. How does the electrical performance of your battery vary with temperature, especially at extremely cold (-40C) and extremely hot (80C) conditions?
...and more on that point, I drive an RX-7 and my engine puts out _extreme_ amounts of heat under the hood. a 50C top-end probably isn't enough for driving on hot days.
I would go for one of these without a second thought because a) though my car is light, reducing more weight helps out loads with performance and b) these things are known to kill alternators and I'd love advance warning of when I might end up stranded without having to test the battery's volts every day.
Hey, co-founder here. It's very forgiving to temperature. Supercapacitors don't store energy using a chemical reaction, which make them a lot less finicky. On the low side, our power architecture also allows us to boost the voltage slightly if we sense that its cold outside, so we can account for the increase in resistance. It's also still go superior lifetime at high temps as well.
EDIT: I'm not trying to inject bad feelings here or contradict Ohm. I'm just clarifying the effect of temperature on supercap life. There is some effect on cap lifetime at high temps. I hope the product succeeds. I know sailors have using lithium batteries for a while now, but as mentioned elsewhere, they are shockingly expensive (like $6k).
Thanks for the comment. It is something we need to look into a bit more. Generally we haven't seen the capacitors be the limiting factor in lifetime, but they might be in extremely hot situations. I'll do some more work on getting a definite answer here so we can be more careful/specific about our claims in the future.
I've lived in both Cambridge, MA and Scottsdale, AZ, and my batteries routinely die in under 2 years. I think it's mostly a function of my (infrequent) driving habits.
I've never figured out why some batteries last and others don't. My '05 6MT V6 sedan still had its OEM battery when the starter finally refused to turn over in 2013. My wife's '07 5AT I4 sedan just got its fourth battery this month. My car grew up in central Kentucky, hers spent its first 3 years in New England before also moving to ol' Kintuck.
Not that this was necessarily the case with your vehicles, but battery placement in a vehicle will directly affect its lifespan. If it's closer to a heat source (e.g. the engine), it will die much faster. This is why some manufacturers put them in the wheel well or the trunk.
Depth of discharge can be very important. When lead-acids discharge, the metal in the electrodes moves into the electrolyte, making the electrodes smaller and weaker. Couple that with electrodes made very "spongey" to increase surface area to maximize the cranking current, and they can start to flake off and fall apart if discharged enough.
I'm glad you've been so fortunate. There definitely is some variation. There are a lot of outliers on the other side too. The 3-4 year number is what most manufacturers themselves claim.
My car has a significant design flaw(1), in that it allows children to turn on the backseat car lights and leave them on. I've had more dead batteries in the five years I've had sentient children than I've had in the 40 years prior. This is a great idea.
The problem is I don't understand how the battery would shut down just lights and accessories without a) losing all your radio presets b) requiring entering the anti-theft code in the radio (risky because if you get it wrong you can brick your radio) c) still have power to know that you're trying to start the car.
It seems to me this requires more than internal battery smarts but changes to the car's wiring to have separate battery connections for computer, accessory, and starter.
Right now most cars have just one big post clamp for the + and - battery connections.
Yeah, it's really a problem best solved at the car level. Brownout detectors shut off all but the most important systems in the car, and then shut off everything when the battery is reaching critical levels to prevent damage.
This is cool. Rarely in such established industries do people step back and reconsider the actual product requirements in such a practical way. Car batteries serve two TOTALLY distinct purposes (starting engine and running electronics), and this is a great solution for those.
I'd be worried about the impact of rapidly increasing electrification (including hybrids) on the high end market (the most likely consumers for this), but it's such a huge market at present that it probably doesn't matter.
Thanks for the kind words! Electrification is definitely happening, but for now there's plenty of market to go around. In the end we think the tech we are creating will be more an enabler of electrification rather than its victim. :)
> if it’s ever about to reach the point that it’ll no longer be able to start your car, it’ll just turn itself off. Your lights will fade out and the radio will go quiet — but once you turn the key, everything will spring right back to life, no jump start required.
How does that work? If the battery stops providing current to prevent itself from being fully drained, you're not going to have power to the car's computers to actually start anything.
It will know when the internal batteries are running low (the internal charge/discharge monitor IC doing battery "gas gauge" measuring). It'll maintain a reserve of a few crank's worth of energy, and trigger shutdown before that's exhausted.
It can also tell if the engine is running, because the alternator will be, and charging it. It can also monitor the active discharge current.
If the battery is low and there's a small but fairly constant discharge, it's probably lights/radio, and a timeout of an hour might be reasonable.
It could then either cut power completely, or regulate discharge current to a couple of milliamps or something, just enough to sense teh spike when the starter motor is switched in. At that point, it switches in the supercap or goes back to full power 12v mode, and the starter gets cranked.
The only downside I can see is that fully isolating the battery may have side effects that upset the ECU, radio or immobiliser system (I recall our radio would go into 'presumed stolen' mode if fully disconnected and require a PIN to work properly, I have no idea if/how that happens in modern cars though)
A "dead" lead-acid battery often isn't dead enough for that to happen, just htat it can't supply the ~200A that the starter requires to crank.
And will I have to reset all of my radio stations every time I leave the dome light on? With a manual I would almost rather run the battery until it is nearly dead.
Great product idea! One possible side market: have you looked at adapting the capacitor+battery combo for electric bicycles? It could be a great application: batteries for energy density, a capacitor as a buffer that can be filled quickly in a pinch (for charging while out and about, or from regenerative braking) and the capacitor could be discharged quickly for high-power acceleration. For short trips the capacitor would bear much of the load, saving battery cycles. The total capacity may need to be somewhat higher than 10Ah, but probably not much higher.
Around the same order of magnitude. Some are less than ten, some are more. It seems like most are aiming for about 10-15Ah these days, at 36V, 48V, or higher. Since capacity translates into range, the greater the better.
Hi Hunter. Do you all plan to offer the battery in a minimal form factor (without the group 35 adapter)? I currently am running one of the Shorai LiFePo4 batteries in my track car. I really love the small size and weight, and would be willing to work around the smaller form factor.
Yes, it will be available in a smaller form factor. The core of the device will be a single modular design that will be inserted in the shell shown to give it the Group 35 size. Thanks for the kind words!
Nope! It could be the exact same internals. We'd just need to repackage it. The voltage on the capacitors is determined by the systems charging them. As long as its below the absolute rating for the caps, it will work. I believe most motorcycles actually operate at the same voltages as cars, though I could be mistaken.
How much safety testing have you done on your battery? Specifically, if an Ohm battery is involved in a collision, how will it fare? I know you are not content with shipping anything you aren't comfortable with your own family members driving with [1]. But, how do you know this? What makes you so sure? I don't mean to come across as interrogative - I am just curious.
Yeah, safety is obviously the most important thing. Right now we're basing the safety claims on the those of the component manufacturers. But it's also going to be a function of the enclosure and component locations, etc. Once all of that is finalized, we'll have a 3rd party lab do abuse testing, crush testing, etc to make sure there aren't any bad failure modes. There's lots of good processes and test procedures already out there for doing that kind of testing on batteries.
Have you calculated how much money a typical driver would save in fuel due to losing 34 lbs of weight?
I have no idea if this ends up being a significant number, but I think the average driver spends somewhere around $10k in fuel over the expected lifetime of this battery; if cutting down the weight by 1-2% reduces fuel consumption by a comparable amount then Ohm would pay for itself.
It depends on a lot of things of course, but yes, over the lifetime of the battery, it will pay for at least a large percentage of itself. We estimate about $10 a year gas savings.
I was writing a reply yesterday but didn't finish it-
I was going to say, for the first iteration of the product you could consider using classic lead-acid instead of LiPo. It's cheap, so it would help keep you price-competitive. It's absolutely proven as an automotive battery chemistry.
The difference vs. a classic battery would be, your smart circuitry to shut off the battery, and the cap stage would allow for a tiny battery even on big engines. Your LiPo model already sacrifices capacity, and the only other reason for a big battery is CCA, which the caps solve. Thus you could put an itty-bitty 10Ah lead-acid in an F-550. Bigger & heavier than a 10Ah LiPo? Sure, but still way smaller and lighter than modern F-550 batteries.
You could then move to LiPo for later versions as you get the truly novel parts of the product dialed in and costs starts to come down.
The DOT regulates your ability to physically ship batteries through the mail, but there's actually no formal stamp of
approval that the DOT gives car batteries. They do have approval processes for other car parts, including electric car batteries though. We've been doing our own temperature and lifecycle testing so far, but we're still having 3rd party labs repeat all of that and also do destructive safety tests.
I don't know how much you can talk about the tech, but I'm interested in how it fits with existing batteries & applications. Is it possibly an add-on to lead acid? A better jump starter? What about industrial like large motor plants where you need a jolt to get a lot of weight moving?
Actually, our very first prototype was a thing that sat on top your existing car battery. After talking to some people, it seemed like they preferred it integrated into the battery itself. It makes the price easier too, since you're not spending money on a battery AND a thing you put on top of it, just a better battery.
Industrial motors aren't something I've looked into a lot yet, but it could be interesting. I was just talking with someone the other day about using supercaps in robotics applications. Apparently some people are already putting small supercaps in the joints near the motors to help provide surge current during high accelerations or loads.
It varies based on the specific car you have, but the short answer is "several". We've been measuring the current needed to start a bunch of different cars, and the results are pretty varied (based on temperature, engine compression, size, etc). One of our testers often needs a couple of starting attempts on his car and it sometimes takes him 3-4 tries before it starts with Ohm.
Stricter regulations on shipping methods than for other cell chemistries.
Degrades at high temperatures.
However, for Lithium Iron Phosphate LiFePO4:
"Lithium phosphate cells are incombustible in the event of mishandling during charge or discharge, they are more stable under overcharge or short circuit conditions and they can withstand high temperatures without decomposing."
The capacitors are fairly immune to temperature variation since they don't store energy using a chemical reaction, and we can also dynamically adjust the standing voltage of the caps to increase power in cold conditions.
We believe so, but don't want to say it until we can verify for sure. Our temp chamber unfortunately has trouble pushing anything south of -20F and it's a bit hard to find weather that cold in August.
Is that expected to be sufficient? Typical automotive electrical components are rated over -40C to 85 or 105C. I think the engine compartment is typically hotter than 50C when a car is running. This might be more suitable to a car that mounts the battery remotely: I have seen BMWs with the battery in the trunk.
We're being conservative with the temperature rating for now. The components are rated better than that, but we're still running cycle tests in our temp chamber and waiting to get the system tested by an outside lab.
It's not sufficient in Canada. We regularly see temperatures below 30 C. Hopefully they can push it lower, because a battery that quits when it's cold out is pretty much worthless up here.
Ohm can be used for racing, assuming the rules of the race don't require using a stock battery. A lot of our early users and testers actually come from the racing community.
How does it handle a car that's iffy on starting? It's probably not hard to get something that'll crank a starter for a few seconds. But what happens if it needs to crank for 60 seconds over a 90 second window?
I've got a 2006 Forester with a manual. I'll occasionally stall it backing out of a parking spot, so I'll have to start it again. For some reason it's much more difficult to start in between cold and warmed up, so it'll take several seconds of cranking to fire back up. If I were to stall it again trying to get going, would I then be in trouble?
It doesn't happen often, perhaps only once a month. But if I'm stuck there for 30 seconds while the LiFe batteries recharge the supercap I'm not going to be happy.
It's hard for me to say exactly how many times you can start it before having to wait for the caps to charge back up, since we've measured a surprisingly high variation of required starting current over a bunch of different cars. One of our testers drives a Datsun 240z (it's really sweet) and sometimes needs a few cranks to get it going. He hasn't had to change his behavior from his old battery, so he's getting at least a few attempts over a short period without needing to wait for recharging. One other cool trick we can do is charge the capacitors slightly higher to deliver more current on a second starting attempt, which will hopefully reduce the number of cranking attempts you need.
Subaru ECU cold start logic is, well, questionable at best.
As a side note, if your car is stalling that frequently, I would suggest adjusting the clutch engagement position. Sounds like its either very low or way too high.
It's definitely driver error and not the car's fault. I try not to rev too hard and slip too long, and it occasionally results in a stall.
I'm spoiled from having driven a number of very powerful manuals. Big engines mean a lot of rotating mass which means that no revving is needed, just pop the clutch and go. That extra rotating mass also means that the ECU has more time to notice the drop in RPM and give it a little extra gas to bring idle back up.
Not so in the Subaru. It's a very light engine and seemingly a pretty light flywheel too.
No idea, but one of the cars that I learned to drive stick in was a friend's 2003 Mustang Cobra. All cast iron engine and something like 400WHP. I don't know that the weight of the flywheel was everything, the crankshaft weighs a lot and I think even the moving mass of the pistons and rods translates into rotational inertia. Finally having 8 cylinders versus 4 means that your engine response time is theoretically twice as fast.
When the clutch engagement time is say 1 second and your engine is idling at 900 rpm you're only doing 1.5 rev/sec. In a four stroke, four cylinder engine that means you're getting on average 1.5 combustion events per second. In the 1 second engagement, you get 1 or 2 combustion events. In the 8 cylinder you get at least 2 and probably 3.
I thought about doing the math for how much energy is in a cylinder firing versus stored in the rotational inertia of the moving parts, but honestly I don't know that I really care. I know anecdotally that big engines make it easier to get cars moving for some reason, and that smaller engines make it a little more difficult. I just speculated as to why I thought that might be.
I'd gamble it has more to do with the fact you have to overcome the resistance of 2 extra axles and mechanical differentials of the AWD forester that is making it appear to be a bit more difficult than the lazy v8 2WD Cobra.
With that said, check out where the engagement of your clutch is. I've had people complain about grabby clutches(stalling) only to find out the engagement point is almost at the top of the throw (Former Subaru tech)
Recently my wife's car batter died, end of life. When a new battery was put in it the car ran poorly. Apparently when the battery dies something in the car resets and the car "figures" out the settings again and runs rough at idle. We called a repair shop and they said to just wait a few days and it will fix itself. Which was true, runs fine now. The moral of the story is that with a new car if the battery dies, weird things happen.
I've experienced this too. On a year 2000 Toyota with a couple hundred thousand miles on it, battery removal literally makes the car not know how to move for 10-15 minutes. The manual says that the car adapts to "driving style" and engine age/performance; it apparently gets to relearn all of that in a hurry after a reset.
TL;DR: The car wakes up with amnesia and has to discover for itself that it's old.
You're right. Pure lithium-ion batteries definitely are available. Besides price, one of the reasons they haven't been adopted is they don't have great performance over temperature. By using supercapacitors, we are able to make it a lot more immune to temperature.
We really approached the problem from the opposite direction. We started with supercapacitors and asked ourselves how we could make a reliable system around them. Huge current surges at the levels needed for starting a car are hugely destructive for batteries. It's almost as bad as just shorting them with a wrench. We decided that capacitors were fundamentally better suited for what a car battery does.
This price has come down by 66% in just a couple of years. A company I used to work for sold these for $1500. The reason people are willing to spend this money is because these are geared toward drag racing, mainly for weight reduction. Compared to other reduction paths, $1500 to remove 30lbs is cheap. The main thing to realize though is that this is a market geared towards people who have purpose-built a car to drive for 10 seconds at a time, a couple times a weekend. Everything geared toward this market is expensive, because basic entry into the market requires a relatively large investment, and companies know that consumers are willing to spend. Its a lot like the wedding industry, in that regard. On the other hand, high margins are the only way to make money in this segment, as the entire market is less than 100,000 consumers.
Sorry, it isn't my intention to be less than cordial. I just don't see a problem screaming for a fix. Nobody I know is screaming about the batteries in their cars. I don't even know (or care) what batteries are in our vehicles and I am far more aware of automotive matter than the average person out there.
Longevity isn't an issue.
Weight? People are far more interested in losing 34 lbs of fat from their bodies than 34 lbs of battery from their cars. The former would make them very happy while the latter is completely off their radar.
"It costs more but it's better" (paraphrasing). The world is littered with the carcasses of businesses who thought "better" was equivalent to "sales". I've done that before and lived to learn a few expensive lessons. This might very well be better in objective terms from a certain point of view but people are not going to hand over another $50 for something they truly don't care about. This isn't an iPhone or a Nest type product where "luxury makes me feel good" is part of the mental process.
I do agree the racing community might have interest in something like this. That said, if I were building a race car I would use Lithium Polymer battery packs that deliver tremendous power at a lower volume and weight. Are there rules prohibiting this due to fire hazard issues?
So yesterday Audi/Porsche/VW announced a new v6 engine that will be used in variations across all their vehicles. Further down the line, they said that engine would include an electric drive component as well, incorporating a battery, effectively making all their cars "hybrids".
This seems to be the trend, see racing tech (Formula 1, WEC, etc.). We will probably see this in all new consumer cars sometime soon.
Once every car has a battery, wouldn't the standard car battery that's most common today be obsolete?
At your price point, performance/luxury cars seem to be your only market, which are also the cars that will electric drive before mid to low end cars. These are also the owners who will replace their cars every 3-5 years anyway. Either from a 3 year lease or the 4 year warranty is out and they want something new.
I don't mean to be discouraging but, it seems your market viability, if there is any to begin with, is already limited to 5 years at the most.
I do love the idea of saving 30 lbs weight, it's negligible for most of my driving in my sports coupe, but I like to feel like it's making a difference!
Current electric cars and hybrids still all have 12V lead acid batteries in them (Teslas, Leafs, Priuses etc). These are typically used to drive the lights, windscreen wipers etc but also to bootstrap the charging process.
I think in some states it's required by law, and although this is probably an artifact of history (you must be able to run your hazards even if you're out of petrol etc) it still means that cars will all have such batteries for the foreseeable future.
I would seriously doubt the market viability being five years. Car manufactures like homogeneous models where possible - so you'd expect to see batteries until every model in the range was a hybrid. It's otherwise additional complexity, and I'd imagine a right pain to get restarted when flat.
A lot of hybrids, like the Prius [1] have a second battery designed for turning over the engine that are designed for different usage cases than the drivetrain batteries; it's also why this battery has a supercapacitor for starting, and lithium polymers for the rest of the time. Additionally, there are a lot of people who like older cars, think hotrodders, etc, where a battery like this would also be useful. It's definitely more of a niche product, but I do see a market for more than five years.
Slight correction as a Gen II Prius driver: In the Prius, the 12V battery only runs the control electronics of the car (and a few small motors like the wipers); the engine is turned over by a high-voltage motor running from the main "traction" battery. The smaller 12V battery is charged from the high-voltage battery which is itself charged from the gasoline engine via the hybrid transmission. All that is to say that the 12V battery doesn't see huge load spikes like a regular starter battery (even the air conditioning compressor runs off the high-voltage pack). It would be GREAT to have a supercapacitor bank backing the traction battery in parallel though, particularly for storing the energy recovered from regenerative braking.
Thanks. Should have known not to trust a battery vendor's page touting its superior cold cranking amps for a hybrid. Though for the hybrid battery pack, you'd want to stick with more traditional batteries. Supercapacitors are better when you need to provide a lot of current at once, but they don't have nearly the energy density of lithium, or even lead, batteries.
It is possible, though, that a supercapacitor bank could be useful in the frontend to serve much like this battery does. I could see it being potentially useful to have the supercapacitor get the motors turning to provide torque as fast as possible, with the regular batteries providing the lower current to keep things going.
> At your price point, performance/luxury cars seem to be your only market,
I'm not sure even that will be a market they can cater to as newer performance/luxury cars have a massive amount of electronics and computers inside that put a heavy continuous drain on the battery (and continue to drain even when the car isn't running).
Considering this new battery can't even hold the amount of power that a normal car battery can, I don't see it being used in high-draw luxury vehicles.
We don't think this will be a major issue. One of the nice things about LiFePo4 batteries is that it has an enormous cycle life compare to lead-acid and can provide a really high level of power throughout its entire discharge range. The power of lead-acid degrades pretty quickly and you can have significant trouble cranking your car even if it still has half of its energy available. If the electronics were using high enough amounts of energy to be a concern for our design, it would also likely mean that the cars would have trouble starting with a lead-acid.
> Once every car has a battery, wouldn't the standard car battery that's most common today be obsolete?
That day is still a long way away, and once it arrives, there will still be large numbers of classic and modern hot rods on the road. That's not a small market.
> At your price point, performance/luxury cars seem to be your only market
The US automotive aftermarket was around $300 billion in 2013.
> ...already limited to 5 years at the most.
I seriously doubt that even the majority of vehicles on the road will be EVs within 5 years. And 5 years is plenty of time to develop other innovative automotive products.
>At your price point, performance/luxury cars seem to be your only market
Is this really true? It sounded from the article like they're only about $50 more than a typical battery, unless I missed something. I could see some people with normal cars shelling out $50 for the longer life and features to avoid a dead battery, even if the reduced weight doesn't matter much to them.
>I could see some people with normal cars shelling out $50 for the longer life and features to avoid a dead battery, even if the reduced weight doesn't matter much to them.
my current BMW battery cost $130 and rated for something like 6 years - the car is 14.5 years old, had batteries replaced at 6.5 and 12.5 years (both times it wasn't dead yet, just on suggestion by the shop).
> I could see some people with normal cars shelling out $50 for the longer life
Most people will take their car to a repair shop when they have problems with their battery and will take whatever battery the tech/shop suggests (as long as its in their price range).
Unless this company starts pitching their batteries really well to these repair shops, they're not going to see much business.
Yes, the caps. Classically the reason we use lead-acid in cars is its tremendous power density. Here they are combining LiPo (high energy density) with caps (high power density).
My truck battery pumps out 750CA for short bursts. That's about 12 horsepower. Lithium batteries can only accomplish that in large parallel banks.
Storing a lot of energy and delivering it faster are two separate problems. The batteries you linked are design to store a lot of energy, but are only rated to deliver it at 30Amps. Cranking even a medium sized sedan would take 5x that or more. Creating something that can do that reliably requires a lower energy density. LiFePO4 by itself also doesn't stand up particularly well to cold temperature. The capacitors do most of the heavy lifting involved in starting the car. Using the combination of the two also enables some other nice things like the dead battery prevention.
There are other lightweight batteries out there, but they generally aren't suitable for daily use for one reason or another. The usual sacrifices are either lifetime or performance over temperature. The battery you linked is only warrantied for 2 years and likely wouldn't work south of freezing - not quite what you'd expect for the price tag. We think we can already beat them on value prop, but with a little bit more work, we think we'll be able to get them cheaper than other lightweight solutions and eventually price competitive with a normal lead-acid.
It does list itself as "extreme temperature tolerant" and suitable for snowmobiles. And to be honest, a 2 year warranty from a long-established company is worth more to me than a 7-year warranty from a company founded this year that could be gone next year, no offense.
Just trying to share some of the challenges you face.
You would choose the Ohm because Ohm is a startup, and... startups! YEAH! Tech! Oh yeah! And stuff...
Like so much else out there, they want you to think it's better when in reality it's at best a niche offering that's going to be worse for most people. But there are a lot of people out there who are happy to spend 2x or 5x or even 10x on something that a "fellow startup" is making, just because it's novel or made by another small company, regardless of its actual merit. As they've said forever, a fool and his money are soon parted.
It would be nice if the battery had multiple outputs: for example, connect the capacitor to just the starter motor and have a second output for everything else. This way all the lights in the car would not dim during starting (why should the electronics have to deal with brown-outs?). Diodes could be used for the charging current input.
it is only 10Ah! Comparing that to 45Ah+ typical car battery is like that MongoDB write performance comparison without actual writing to disk :)
Such small capacity would work only for perfectly starting engine. Any issues and you're out of capacity. Cranking an engine requires hundreds of Amperes, like 500-800A. Thus each 10s of cranking burns 1.5-2.5Ah.
The CCA rating of a car battery is the current the cold battery can produce during 30s. 10Ah LiPo at 30C would mean maximum 300 CCA - i don't think it would satisfy any official reqs for any passenger car around. The super capacitor produces higher current, yet for much shorter bursts. Thus again only easy starting engines on smaller cars.
One of the things we discovered is it actually takes a lot less current and energy to start engine than we originally thought. It's rare that anyone even uses 1% of the capacity of a regular lead-acid while cranking. So we're confident 10AH is more than enough.
The high capacity of most lead-acid is really just a side-effect of making a battery that can deliver high current over a reasonable lifetime.
You don't get the massive amount of power required for the starter from the alternator. You leave your car on so that in case the other car is severely broken or zaps all the remaining juice in your car's battery you don't end up stranded.
You don't need to; I used to have a really crummy set of jumper cables that wouldn't actually pass enough power to start my car with the battery dead. I'd have to stay connected to the other car long enough to let its alternator charge my battery enough to start.
Hey! One of the founders here, Like another poster said, you should have your car running when jumping another car, but yes, Ohm can be used to jump another car (and vice versa).
On a shelf: upwards of 6 months.
In a car: around a month if it's powering all the electronics. We also intend to have a switch that can electrically disconnect the battery. It would stop powering everything, but it would also allow you to store it in the car for the same 6+ months, switch it back on, and still start the engine.
Oh, please do! Some of my cars will sit for a month and then the battery is dead due to parasitic drain. It's a pain to plan ahead and use tools to disconnect the posts.
You should get a bit longer than just a month of disuse before it shuts itself off. Are there modern cars that don't even let you use the key to open the door? I know Tesla has the thing where the handle is flush with the door, but are other cars doing that too now?
Wouldn't this need to get DOT approval? Also looking at the replies from the founder, it looks like there hasn't been much actual safety testing done yet.
We've been asked this a few times, and from everything we've been able to find. DOT approval doesn't apply to starting batteries. There are two different things people generally refer to when they mention. 1) Transporting lithium batteries above a certain size requires an approval. For this one, the battery we use is below the levels they regulate. 2) there are also approvals you have to get for electric vehicle batteries which primarily stipulates a maximum amount of volume of electrolyte that it can spill in the case of it being destroyed in a crash, which doesn't apply to us at all. If we're wrong, and there is some regulation that does apply to us, we'd be more than happy to know about it. Please link me to it.
As far as testing, we've been driving on it ourselves for 5 months now. We have a cycle and temperature testing setup in our shop. We will do all of the testing we need to before we ship to anyone. Our earliest customers are likely to be the people in the world closest to us. We won't give you anything we wouldn't feel comfortable with them using.
I was about to say the same thing. I've had a lithium iron battery in my motorcycle for years. I personally love it (it allows me to leave the bike sitting for longer without putting it on a battery tender), and it's much lighter. Just comes at a higher cost.
Great idea in a very stagnant market. How do the LiFePO4 cells perform at high temperatures? I've worked with this battery chemistry before, and found most off the shelf cells have internal safety circuitry that disconnects the battery at temperatures >70C. Typical engine running temperature is 60-80C (or as much as 90 on a hot day).
Hey Jason, good question. It turns out to be a non-issue. Lead-acid batteries have terrible lifetimes at high temperatures, so cars are already designed with enough distance between the engine and battery and enough circulation to ensure the battery is never more than a few degrees above ambient. The batteries in our design also aren't generally active while the engine is running. Let me know if that addresses your concerns.
I'm curious to see if you expect to get 7 years life on a LiFePO4 in hot states. I just measured the battery temp (at the terminal) on my truck, it was 163 ºF. Road surface temp is 155 ºF.
This is quite common, everyday summer stuff here in Texas.
It seems very unlikely that you can hold a LiFePO4 at 100% state of charge in a temperature environment like this and still get anywhere near 7 years of life.
Are you doing something like using a 20 A-H battery, charged to 70% SOC or something, to deal with high-heat/high SOC degradation?
Perhaps I am in the minority here, but in the 15 years I've owned cars I don't remember a time when I planned changing the battery. It was happens in the worst time, most frequently when I'm trying to get to work or home. So getting a new battery is always an emergency to get my car rolling so I don't get it towed or start accumulating parking tickets. Getting an eco-friendly battery is the last of my worries. I wonder how many folks out there feel the same and how this could impact a novel product like this going forward.
I wonder what the long game is here. High end replacement batteries for existing cars seems like a beachhead attempt rather than the real target.
Apart from the environmentals (see sandworm101), are debatable and the main tradeoffs is weight vs capacity.
Sports car enthusiasts seems like the most likely market. Some of these guys will drill holes into foot pedals to save grams. You'd need to look at what's available to them to see if this would sell. Comparing to average lead batteries is not much use.
Have these guys tried to start atmospheric diesel at -20 C? That capacity is absurdly low. I roll my 80 hp diesel with 7 times the capacity.
I see no benefit at all - you take something reliable as hell, make it unrealiable by adding hardware and software, reduce the capacity, just to shave 20 pounds of weight of a 3000 pound car.
If it was normal sized battery with some smarts - it could have been useful. But the current incarnation is - works only in the very moderate climates with mild winters.
How does the Ohm battery handle extended cold conditions? I lived in a cold climate for a number of years in grad school, cold but not block-warmer cold. My experience was that I had to pay close attention to the cold-cranking amps rating of replacement batteries, so they'd still be able to start my car under the long-duress of winter. Likewise, I found that car batteries seemed to be consumables relative to my warm-climate experience().
It works really well in low temperatures. Supercapacitors don't store energy using a chemical reaction, which makes them a lot less finicky over a temperature range. We can also react to lower temperatures by increasing the voltage on the capacitors to a higher, but still safe, level to help compensate for the increased difficulty of cranking engines at low temperatures.
I've prototyped similar with just 7 maxwell caps in series wired in parallel with a lead-acid battery. The caps can start an engine entirely on their own, and the lead-acid maintains the voltage when off. It works fairly well.
I think someone already sells a device to work like that for commercial tractors, and I was wondering when someone more interested in starting a company than I am would realize you could have a tiny battery plus EDLCs for a car.
I'd love to have a lighter bank of batteries in my (small) sailing yacht but I need something that can be "deep-cycled". Getting rid of several hundred pounds of batteries would leave capacity for more stuff!
I could replace the engine's starter battery with this one for a bit of weight savings ... and it's protected from the "house" circuits" by a charging diode, so there's no risk of discharge.
I remember watching youtube videos of a guy starting his car with just a capacitor a year ago (was it one of you guys?) and thought this idea had a lot of potential. Good on you for bringing it to market.
Please be careful to not make it too 'smart'. I don't think a car battery needs to be connected to the internet of things that can be remotely hacked into :-).
We've been trying to avoid using the term "smart battery" for that very reason haha. We don't think people would be psyched about having a BLE connection and an app for their car battery.
JOOC, what is the CCA rating? I don't recall seeing it in the comments.
There aren't many of us who run winches, but thems of us that do want quite a few (650 CCA is not uncommon, and some winch manufacturers recommend deep cycle batteries like the Yellowtop Optima).
A quick search shows that some lighter duty winches will draw 60-90A, while heavier duty winches can easily draw ~250A to ~350A.
The winch I'll be installing next month as a 10,000lb pull rating. That requires a lot of power.... (Why 5T? Because my Jeep weighs a hair over 2.25T, and if it's stuck in the mud, I'll need to overcome the mud....)
A winch is typically connected directly to the battery and is controlled via a relay: The control cable uses very low current to activate/deactivate a solenoid that switches the winch on/off.
(It's an interesting and ironic bit of jargon: When winch owners refer to a winch's solenoids, they are referring to the control relays... ...but any winch contains at least three solenoids, one low-draw solenoid in the relay, and two high-draw solenoids in the winch itself, that is, the electromagnets that are the heart of the motor....)
How does this battery handle -40C weather? What about sitting at -40C for say 12 hours (not everywhere has plugins for block heaters). Currently a ~$100 winter battery will handle that no problem. I'm from Canada so this is not a hypothetical question.
We think we can make it work, but we don't want to promise anything before we're certain we can delivery. If you're in that kind of environment, we'd love to have you test a unit over the winter and help find out for sure. Feel free to drop me an email at hello@getohm.com.
> Oh, and its lifespan (7 years) is about twice that of a lead-acid battery (3-4 years).
Nonsense; lead acid batteries easily last 5 years or more.
Since the article lowballs the life of a lead-acid battery, it's reasonable to suspect that it's likewise overestimating the seven year life of this new battery, which would make them about equal.
> They’re filled with garbage materials that are terrible for the planet.
More FUD. The garbage materials are sealed, and batteries get recycled. Places that sell you the new one take back the old one, generally.
Battery places are not going to know what to do with this new-fangled thing.
So it's down to the 6 pounds and gas mileage. Okay, realistically, let's talk about the environment now: this is for an internal-combustion-engine car that spews several tonnes of carbon into the atmosphere. If you want to save the planet, ride a bicycle. Still, this could make in excess of a one percent difference in fuel economy, which is significant, and will easily more than pay for the battery. Say you spend 200 bucks on fuel per month. Get 3 of those back thanks to the 6 pound battery, that's 36 over 12 months. If it holds up for 10 years, 360 saved.
Easier on the lower back is a plus. For many people, this is a do not care; only the DIY battery swappers who do it in the parking lot will be somewhat relieved, as well as the people who swap batteries as part of their work duties.
Poor capacity is a minus. People don't just run the stereo while parked; sometimes they have the headlights on or use other accessories, not always ones built-into the car. On a warm day you might listen to the stereo, and have a fan circulating the air. How about emergencies? If you're stranded somewhere with a dead engine, it's better to have more battery capacity than less for whatever. Flashing your lights at another car, say.
> They die without warning
That is not entirely true: there are in fact warning signs which, combined with age (being say > 5 years) add up to "change the battery". A lead-acid batter that has given you five warnings will then die without an additional warning, if five warnings is all which that battery has been blessed with. Those who don't recognize the warnings of course curse the battery for dying without a warning.
Who is to say this battery won't exhibit sudden failure modes? Suppose the business takes off and millions of these that are actually sold to consumers are made in sweatshops overseas, with all kinds of corners cut to save costs. Will those units still hold up? Let's compare prototype to prototype, shipping product on the shelves with shipping product on the shelves.
You would not be far wrong in claiming that the lead-acid battery is the world's most environmentally friendly manufactured product. I don't blame Ohm directly for TC's hyperbole; TC is a known rag. But still... have the decency to stand up for the facts.
Knowing how it compares in terms of physical durability would be useful. Not interested in your battery matching the optima, but more to see how it compares. Do you plan to offer an off road version (for cars not street legal)?
> With that in mind, Ohm is focusing on the performance car market first. Those are the guys that’ll rip out their passenger seats to gain a tiny performance gain on the track
Give me a break. With 10 amp hours my car will probably not be able to make through a single engine start.
(2) Car batteries do not last only 3-4 years as per the OP. Car batteries can last decades. There are many variables, but the car in my battery is far older than 4 years. (lol)
(3) Replacing an easily-recyclable product with a less-recyclable one is no step forwards.
(4) XX addressed by OP comment, see below XX This thing is a capacitor? What's the voltage potential in there? Any device with internals significantly beyond that may be a serious fire risk in a crash..
(5) Car batteries are not needlessly heavy, nor are they a stock size. Manufacturers do care about performance. If they thought the car could do with lighter battery they would use one. Have some respect for the thought behind stock engineering before replacing it.
(6) Shutting down the voltage supply can be a real pain. A "dead" battery generally still has enough juice to keep electronics ticking over. Cutting it completely is not like turning off a switch. It often means resetting/rebooting stuff once the voltage is restored. For some (BMW) it can even mean a trip to the dealership for a special new battery ritual. http://www.bimmerforums.com/forum/showthread.php?1355106-Why...