

Rapidly falling costs of battery packs for electric vehicles - crawshaw
http://www.nature.com/nclimate/journal/v5/n4/full/nclimate2564.html

======
vonklaus
Does anyone know how long something like the new Tesla powerwall lasts? What
happens after the useful life of the hardware, can they be recycled/fixed?

~~~
bigiain
I'm not sure about the specific chemistry used in Teslas thing, but consumer
grade Lithium Polymer cells are usually quoted as maintaining 80% of initial
capacity after 1000 charge/discharge cycles (when using proper recharging gear
- sub $10 Chinese toys often ignore charge requirements altogether and trash
or set fire to lipos within a few dozen cycles). Which fit's quite well with
observations of phone batteries becoming problematic after ~3 years of daily
charging.

~~~
SeanLuke
Keep in mind that phone batteries, and laptop batteries, are generally charged
to the top and then often completely exhausted. This is a worst case state-of-
charge scenario for battery life, and doesn't happen in car batteries etc. For
example, the Chevy Volt doesn't permit its battery to be charged over 80% or
discharged less than 30%. GM expects its battery to drop only 10% after 5000
cycles.

~~~
MrFoof
Teslas do similar on the top-end. They don't normally charge past 80%. You can
override this behavior in preparation for a long trip to ensure you have extra
range available, but it reverts back to the default setting automatically
after a few days.

~~~
SeanLuke
> They don't normally charge past 80%.

I thought for Tesla it's 92% for a standard charge. The Volt is extremely
conservative in this regard (Chevy was first out the gate).

~~~
Animats
As Lutz says in his book "Car guys vs. bean counters", that was done to make
the Leaf battery last longer. The car industry knows that 80% of trips are
under 40 miles, so most of the time, that's enough range. Longer, and they cut
in the gasoline engine, so there's no reason to stress the battery life.

~~~
SeanLuke
??? This was an entirely confused comment. (1) we are talking about SOC, not
capacity, and (2) why are you talking about the Leaf?

------
pcunite
Personally, I'm very excited about electric vehicles. There are five in my
family, so we have a big vehicle. So, to move something the size of a Suburban
is a necessity. The Tesla Model X looks like a possibility.

~~~
dublinben
Most full-size sedans can comfortably transport five adults. Get a station
wagon, and you've got plenty of cargo space too.

You don't really need a massive SUV.

~~~
evilduck
Most families of 5 have a number of years where they are not seating "five
adults". I drive a sedan and have two kids under 5 years old, a 5th passenger
is basically out of the question. If you had 3 kids in car seats, a vehicle
with a third row is seating is your only option.

~~~
brc
I have 3 across the back seat, all in child seats. It's more possible than
most people realise.

Oversized child seats are a major cause of people driving cars bigger than
they need to. I'm not sure how this has happened, but you can end up needing
more space to fit a child than an adult would require. I suspect it's the
proliferation of region- specific child restraint requirements, which has
meant manufacturers have washed their hands of the problem. The car seat
manufacturers have worked out that the more a seat looks like an oversized
sofa for their precious cargo, the more sales they make. I doubt that an inch
extra of foam padding makes any difference in a large impact, but it feeds
into anxiety of new parents.

~~~
evilduck
I would basically agree except that it doesn't change the availability of
smaller car seats, the small sofa chair car sest is practically a universal
design, and the highest rated brands (which is largely synonymous with
"convenient and well designed") are some of the worst offenders of space
usage. I just transitioned one kid to a booster seat and it actually takes up
an normal adult width finally.

------
Shivetya
Battery cost is only part of the problem, the bigger problem is ability to
charge where potential customers live and charging times. Unlike a
conventionally fueled car, or EREV, there is no oops with a five minute fix.
You forget to charge and you have to wait it out.

I think a better application is instead of focusing on individual car buyers
is to go for large government users of vehicles, namely the every day school
bus. A neighboring county logs nearly sixty five thousand miles a day while
school is in session. With nearly nine hundred routes that leaves an average
near eighty miles. Considering the wasted space in the buses structure and
replacement of the engine/drivetrain it certainly looks like a good option.

Regardless of price decreases its the recharge rate that needs a lot of focus.

~~~
bigiain
To be fair, it's not like you can completely ignore the remaining range in
your dead-dinosaur fuelled vehicle either. If you run out of gas on a freeway
or backroad in the middle of nowhere, you're still gonna get annoyed at your
"oops".

I'm probably a bit more aware of this than many - I ride a motorcycle with
only 200 or so km (maybe 130mile) range, and take it _lot_ of places where
keeping a good running tally of where the next fuel options are, and how I'm
gonna get home if the next place happens to be shut.

I suspect that in under 5 years, there'll be roadside assist vehicles with big
3 phase generators on board that are capable of Tesla Supercharger kind of
rates of charge.

~~~
ceequof
AAA did it in 2011: [http://newsroom.aaa.com/2011/07/ev-charging-
statio/](http://newsroom.aaa.com/2011/07/ev-charging-statio/)

"Level 3 charging" here means DC fast charging: 125 amps at 500 volts
(depending on the vehicle)

~~~
bigiain
/me pulls a technicality and claims "minus 4 years" is "less than 5 years" \-
thus being proved correct.

------
dmritard96
non paywall version?

~~~
jessriedel
[http://rdcu.be/cIqD](http://rdcu.be/cIqD)

~~~
vonklaus
Doesn't work on mobile.

