
DIY Powerwall Builders Are Using Recycled Laptop Batteries to Power Their Homes - prostoalex
https://motherboard.vice.com/en_us/article/kzz7zm/diy-powerwall-builders-are-using-recycled-laptop-batteries-to-power-their-homes
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seabird
I appreciate the engineering and time people are putting into these projects.
I absolutely _hate_ the way this article is portraying these people's work.

These are not "consumers who can't afford commercially produced powerwalls."
These are people who could probably work professionally in the field if
they're not already. These projects are not "a little research, invested time,
and a little ingenuity," they are the culmination of years of experience and
passion, along with extreme respect for the technology.

Don't get me wrong, I want people to do this. However, acting like people can
safely dive in to high-energy electronics/electrical projects head-first is
stupid.

~~~
chris11
I really agree with you. The idea of a homebuilt powerwall sounds really cool.
But it's not something I would come close to working with.

Awhile ago I did a some volunteer work at a radio station. One of my tasks was
to check for arcing. That involved going into the transformer room, disabling
the safety systems, unracking some of the electrical components, powering the
system on, turning off the lights and then looking for flashes from electrical
arcs. It also involved going out at night with night vision goggles to check
for arcing on the antenna. If we saw anything we knew what needed to be fixed.
Safety was important there, but I developed a healthy respect for electricity.
After working there I'm a little freaked out about the idea of dealing with
high voltage systems.

~~~
Dylan16807
High voltage, sure, but outside of an inverter that you can/should buy
prepackaged none of this needs to be high voltage. The system in the embedded
video has 14 sets of cells in series, meaning 40-60 volts.

~~~
jononor
Danger of electrocution is not particularly high, but can easy start a serious
fire with such batteries. The energy capacity with create a seriously hot arc
if shorted, and there is a potential for thermal runaway of the battery cells.

~~~
kpil
I once saw two marine lead-acid batteries explode and catch fire in the boat
next to mine when the owner had dropped something big enough to short circuit
and not disintegrate itself. Instead a fat copper cable exploded and then
probably both batteries boiled, exploded and then everything caught fire. It
took about 3 seconds.

Luckily he avoided the acid spray, but he had to empty 4 large fire
extinguishers from the nearby boats to put out the fire and cool down the
remains of the batteries enough so they did not immediately catch fire again.

I have a huge respect for what a huge solar array and a big bank of batteries
can do after seeing what a relatively puny battery could actually do.

A standard AC system can't deliver even a percentage of that current.

~~~
King-Aaron
I had something similar happen to me in a Datsun 180B once.

Driving home in the rain, and the tail light wires were submerged in water
that was pooling in the trunk and shorting out. As I put my foot on the brakes
- on the freeway in the pouring rain - the fusible link in the engine bay
decided to just catch on fire instead of being a fusible link. The battery
quickly boiled and I had a sudden and catastrophic engine bay fire on a
crowded road.

A car battery has enough amps to literally use as a welder (two jumper leads,
an arc welding rod and a 550CCA car battery is enough to stick most things
together in an emergency :P ), and is more than enough to create a massive
fire.

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cyphar
One of the really disappointing things about Tesla is how incredibly
proprietary all of their products are. For a company that has such lofty goals
as "saving the world", it feels wrong to me for them to then sell DRM cars and
unrepairable black boxes. Maybe I'm just too idealistic, but surely if we have
an opportunity to create a new market for solar devices why would we decide to
recreate the proprietary world of the 1980s? Creating your own powerwall from
recycled batteries is a pretty neat hack, and I'd hope that people are
publishing free (as in freedom) hardware designs for said battery banks.

~~~
extr
This isn't unique to Telsa, all vehicles are becoming more difficult to repair
as computers and software replace what used to be handled by mechanical
systems. I would actually much prefer to drive next to a Tesla knowing that
the guy behind the wheel (potentially staring into space as it drives itself)
hasn't implemented any "hacks".

A similar argument exists for why DIY battery banks are not ideal. It's not
inconceivable that some dedicated hobbyist engineer pulls it off in a safe
way. But how would you feel if you were over in your neighbors garage and
noticed he had haphazardly wired 600 18650 cells together based on a design he
found on the internet?

~~~
jerkstate
This stuff isn't black magic, it's science and engineering. As more hackers
participate in this space, the open source components and techniques will get
better and better (I'm not familiar with open source battery management
systems but I would bet there is already some good stuff out there). I think
there are a lot bigger dangers to hand-wring over than nerds needing out over
this stuff.

I think there are as many or more car hackers than ever - CAN bus opened car
hacking from the world of the gear head to the world of the computer geek.

~~~
zanny
> As more hackers participate in this space, the open source components and
> techniques will get better and better

I so strongly disagree with this assumption. We got a nascent not even close
to open source scene on x86 and a few hobbyist tweak boards. They still use
proprietary hardware, the firmware is still almost always proprietary, the
drivers are often proprietary, and for general users 99% of their OSes are
proprietary.

And the _consequences_ of that world that doesn't care about right to repair
or software freedoms or having control of computers impacts _me_. I can't get
an x86 pc now without a hardware backdoor, I can't use 802.11an wifi without
proprietary code, I can't display visuals to a screen without proprietary
code. The screen itself is running a ton of proprietary code. My hard drive
has a computer in it and thats wholly proprietary.

And that was in an ecosystem where moddability was handed to us _on a silver
platter_ with ACPI which only existed for IBM and Microsofts sake, not for
anyone elses. It was not a charity. That is why we still have no mobile
platforms that use a standard hardware abstraction layer that you can run a
generic OS on.

The Internet of Things never developed an open source ecosystem. SmartTVs
never developed an open source ecosystem. Set top boxes and consoles never
devleoped an open source ecosystem. Cars almost certainly will _never_ develop
an even remotely functional open source ecosystem - companies will _use_ open
source code, because someone else did the work for them and they can save
money. They won't contribute back, they won't respect their users, and they
won't respect the developers that put in thousands of hours of free labor by
sponsoring them. That isn't open source winning, that is corporate profits
winning.

Look at John Deere. That is where we are going. This is not going to be a
simple matter of find the ethernet jack, telnet into a shell, and start
running code. This is signed payloads, read only rom, and no way to access the
firmware.

If there is an open source car ecosystem, it will be like the open source
phone OS world. A joke, that cannot practically run on anything, that at best
is ripping half of the Android equivalent out of itself to even run. And I
guarantee Ford et al will never be as philanthropic as Google was in open
sourcing Android to release their car OSes middleware like that.

~~~
jerkstate
Firmwares will always be dumped. The crackers can always catch up. If you
really care about this, vote with your debugger.

------
ficklepickle
This sounds like it could be rather dangerous, no? Connecting up a bunch of
old lithium cells of unknown origin and using them hard.

I'd also worry about an insurance claim being denied if it burned my house
down.

However, I very much approve of the DIY ingenuity and repurposing of old
stuff.

~~~
askvictor
If they're from laptops the cells should be safe (as opposed to unknown new
cells from AliExpress which may or may not be to spec); albeit not necessarily
at maximum capacity. As long as appropriate protection circuitry is used, I
don't see how using then hard would make any difference (laptops use batteries
hard too).

~~~
userbinator
_opposed to unknown new cells from AliExpress which may or may not be to spec_

Many of those are actually recycled old cells, likely from laptop batteries,
and could still have a lot of capacity left --- often, what happens is that
one of the cells in the pack fails/goes out of balance and the protection
circuit disables the whole thing, meaning the rest of them are still very much
usable.

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castratikron
I take old laptop batteries apart and use the cells for USB power banks. You
can buy cases off of eBay for a couple bucks that hold two cells and have USB
connectors and a charge controller built in. It's no Powerwall, but they're
still very useful. I power my bike light with them.

~~~
robbles
Would you mind posting a link to the specific case you use?

~~~
castratikron
[http://www.ebay.com/itm/NEW-5600mAh-5V-USB-Power-Bank-
Case-1...](http://www.ebay.com/itm/NEW-5600mAh-5V-USB-Power-Bank-
Case-18650-Battery-Charger-DIY-Case-For-Cell-Phone/351972879495)

~~~
voltagex_
Do the cells have the protection circuits on them?

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esturk
DIY Powerwalls aside, the idea of procuring cells across various "dead"
batteries is amazing for the environment. A lot of times, people just throw
out the entire battery even though only 1 or 2 cell is dead which shuts off
the entire thing. But this is literally the 2nd-R in "Reduce, Reuse, Recycle",
which comes before recycle. I know there's a notion that recycle makes
everything so much cleaner but there's a reason why its the 3rd-R in the
motto.

~~~
dom0
Sadly "Reuse" has found no reflection in the laws and practices in most
industrial countries. For example, giving replaced lab equipment to hobbyists
is a perfect way of reuse, however, very few companies do that. Most rather
send everything to the crusher or exchange it with the manufacturer for a
discount who will do the same.

------
noddy1
Question.. All my device lithium batteries seem to lose ~70% of their ability
to hold charge after 500-1000 cycles, however the tesla car
batteries/powerwall claim to give a decade+ of use despite being built of the
same cells. How does that work?

~~~
Baeocystin
If you never discharged below ~30% or charged above ~80% of their true
capacity, and made sure they always stayed within a comparatively narrow
thermal envelope, your batteries would achieve the same lifespan.

The last quarter-charge in either direction is where ~80% of the lifecycle
wear comes in, and temperature excursions account for much of the rest.

~~~
agumonkey
From what I gathered, lack of internal voltage allow for different chemical
reactions and structural changes that either create resistance, or actual
shorts.

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olfox
I don't think the trouble of scavenging, testing and grouping the laptop
batteries is worth it. The cheapest quality cells I've found costs around 210
euro for 1 kwh. To reach the same capacity you would need ~17 healthy laptop
batteries @ 60wh.

With all the added work, buying just one type of cell seems way better. But
really, why not buy deep cycle lead acids and an auto-watering system? No
hype!

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squarefoot
One thing that often strikes me is the use of 18650 cells in an unpractical,
though technically and economically correct way. Even low power laptops today
employ series of multiple 18650 cells in parallel, so why not make an effort
to bring down the price of bigger cells such as the 26650 or 32650? today the
32650 costs more than the sum of the 18650 cells it replaces, which clearly
explains the wide use of 18650s, but using that one would also reduce the
number of cells by 2 or 3x, therefore saving some good money in both time and
parts (wires, fuses/protections, holders etc). I'm talking about generic
lithium cell production and marketing, not this project which is truly great
even just for avoiding the burial of used cells in some 3rd world landfill.

~~~
parimm
18650's have a 18mm diameter. a 32650 would make most laptops too thick

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erikcw
I've recently started tinkering with this topic and have really enjoyed
jehugarcia'a YouTube channel[1].

[1]
[https://m.youtube.com/channel/UCcMfCkN1juSa49DJFYltOTw](https://m.youtube.com/channel/UCcMfCkN1juSa49DJFYltOTw)

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dave7
As an ecig user / moderate enthusiast, this horrifies me.

18650s are great! It's awesome to know you can easily and cheaply fix an old
laptop battery to better than it's ever been by replacing the cells with some
nice new VTC5s or 25Rs.

Hooking up tons of them with varying capacities and levels of resistance is
surely not wise.

Ecig user knows using even an un-married pair of 18650s in a dual 18650 mod is
a recipe for blowing up in your face sooner or later.

Idk, maybe there's something with such a large number that makes it less
likely to fail catastrophically?

~~~
Dylan16807
In a use case like this you're sticking a hundred cells in parallel and
[dis]charging them at a fraction of C. This makes the variances in capacity
and resistance nearly meaningless. All the cells in a block will safely track
the same voltage, and you can easily put a protection circuit on each block to
keep that voltage in spec.

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6stringmerc
I'm an Amateur Inventor. I used to work in Insurance. You might be able to
guess where this went: Ctrl+F "insurance" \- no results.

Okay, fine, take some risks you innovators you! Just don't expect me to play a
sad song if the experiment burns down your house, your neighbor's house, and
results in criminal charges. Really, I'm not being glib. I will continue not
being glib if what I foresee comes to pass, with potential serious damage to
life and/or property. GL, HF.

~~~
CPUstring
There is an entire section in the article about how most people's first
reaction is "don't burn the house down" and how the community worked together
to create safety systems. The community is aware and working on issues like
that

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tinus_hn
I don't know how true this claim is but if people really put 95% of all
lithium batteries in the trash, that's really sad.

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sdfjkl
From what I've seen (and I haven't really been following this), they're rather
using old electric car batteries to do that. Electric cars have been around
long enough for there to be old/broken ones available now and most of the
cells in their banks are still good.

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captainmuon
I wonder, they don't seem to put protection / monitoring circuitry in on the
per-cell level (which would be prohibitively expensive). How do you know when
a cell or a block of cells go bad? Or does it not matter?

I think it could be bad if the resistance of one increases and you have a
bunch of them in series...

~~~
lolc
Luckily they are not connected in series and the packs are monitored.

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ge96
Isn't it a pain in the ass to find/test all those cells. I think I saw either
an article or a instructables page that had like 100 cells or something. Maybe
it was a thousand. Looked tedious.

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hackernoon
reminds me of this [http://gridlesskits.com](http://gridlesskits.com) – also a
DIY storage/solar project that was on HN a few months ago

~~~
jacobsalome
This is a repost of the Hackernoon article, no?

~~~
nikodunk
Nope, OP of the Hackernoon post here – GK is by us and is the new home of the
project. Thanks for policing though :P

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nerd7473
Sounds interesting

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kwiens
The original story is far better researched and more technical. Can we change
the link to that instead of this repost?

[https://motherboard.vice.com/en_us/article/kzz7zm/diy-
powerw...](https://motherboard.vice.com/en_us/article/kzz7zm/diy-powerwall-
builders-are-using-recycled-laptop-batteries-to-power-their-homes)

~~~
giannidunk
You're right, this is way better!

~~~
locusm
A good place to start is here:
[http://diypowerwalls.com/](http://diypowerwalls.com/)

