Residual Value: Electric Batteries vs. Internal Combustion Engine Vehicles • Hacker News Board

Re: Residual Value: Electric Batteries vs. Internal Combustion Engine Vehicles

#31

Post by baq » Mon, Mar 27, 2017, 12:36 PM UTC

klodolph wrote: post #25

Aron wrote: post #21

I believe that as batteries get on in in life their rate of decay accelerates. It's not a linear process. Maybe there's room for recovering the raw materials effectively, and I wonder if there are upfront tradeoffs that could be exchanged to make that easier. Musk has repeatedly said that scale cost reductions leads ultimately to material cost limit and it's already up to ~50$\130$ per kwH.

Apparently, recovery of lithium from batteries during recycling is not economical, either in terms of money or energy efficiency. Additionally, lithium batteries are more difficult to recycle due to their complexity and the amount of variation between battery types. Compare this with lead acid batteries. About 99% of lead acid batteries are recycled, and the recycling process itself is rather efficient. http://www.sc…

if you plop a lithium recycler in the middle of sahara, or arizona, where solar power is plentiful, you only have to deal with the economics.

i don't see why tesla wouldn't do exactly this a decade or two from now, when there'll be 100x more lithium batteries at or near the limit of useful capacity. it could be literally next door to the gigafactory so they could feed it with a conveyor belt.

Re: Residual Value: Electric Batteries vs. Internal Combustion Engine Vehicles

#32

Post by londons_explore » Mon, Mar 27, 2017, 1:02 PM UTC

dovdovdov wrote: post #18

madengr wrote: post #2

I was surprised there was only about 10% battery loss after 100k miles.

You can google around, these batteries don't use full capacity, instead they have a buffer that kicks in for failed/worn cells.

I'd like to see the behaviour near the end of life for these packs.

Packs in laptops seem to last 3 hours, 2 hours, 1 hour, then 5 minutes, 5 seconds, and "won't even switch on". I wonder if the car packs will have a similar performance cliff.

Re: Residual Value: Electric Batteries vs. Internal Combustion Engine Vehicles

#33

Post by thephilsproject » Mon, Mar 27, 2017, 1:03 PM UTC

dovdovdov wrote: post #18

madengr wrote: post #2

I was surprised there was only about 10% battery loss after 100k miles.

You can google around, these batteries don't use full capacity, instead they have a buffer that kicks in for failed/worn cells.

It's more to reduce degradation - lithium batteries don't like being at 80% state of charge. If you never let them get there, they will last a lot longer.

Re: Residual Value: Electric Batteries vs. Internal Combustion Engine Vehicles

#34

Post by londons_explore » Mon, Mar 27, 2017, 1:12 PM UTC

Typical lithium capacity-age chart:

http://www.calce.umd.edu/batteries/pics/dcir.png

I suspect many users will be happy with their car down to half the usual range (ie. the 700 cycle mark). Even if the original owner isn't happy with this, they can resell to someone needing less range.

After that, there really aren't many cycles left in the battery before it gets to zero. Remember that cycles aren't the only thing degrading batteries - simply storage also causes degradation, so even utilities who rarely have to make use of their batteries (eg only once per week) might only see a year or so use of the cells. I doubt that pays for the installation cost.

Re: Residual Value: Electric Batteries vs. Internal Combustion Engine Vehicles

#35

Post by londons_explore » Mon, Mar 27, 2017, 1:18 PM UTC

URSpider94 wrote: post #7

This is a terrible analysis. First of all, it assumes that the cost of a kWh of battery remains at today's high value. If battery costs are falling rapidly (and they are), then the value of a used battery pack will be driven down as inexpensive new packs come on the market. Second, it ignores the fact that 10-year-old packs will have a substantially higher rate of catastrophic failure than new packs, and if reliabili…

The 18650 cell is fairly standardized though.

One might imagine a machine to rapidly tear the cells out of car battery packs, automatically test each cell, and then reassemble the rest into a new utility level pack.

It might turn out to be better to just grind the whole lot up in a fire suppressing environment, extract the lithium metal, and remake the cells from scratch though.

Re: Residual Value: Electric Batteries vs. Internal Combustion Engine Vehicles

#36

Post by klodolph » Mon, Mar 27, 2017, 1:30 PM UTC

baq wrote: post #31

klodolph wrote: post #25

Earlier quoted context omitted.

Apparently, recovery of lithium from batteries during recycling is not economical, either in terms of money or energy efficiency. Additionally, lithium batteries are more difficult to recycle due to their complexity and the amount of variation between battery types. Compare this with lead acid batteries. About 99% of lead acid batteries are recycled, and the recycling process itself is rather efficient. http://www.sc…

if you plop a lithium recycler in the middle of sahara, or arizona, where solar power is plentiful, you only have to deal with the economics. i don't see why tesla wouldn't do exactly this a decade or two from now, when there'll be 100x more lithium batteries at or near the limit of useful capacity. it could be literally next door to the gigafactory so they could feed it with a conveyor belt.

I'm a little skeptical—it sounds like the claim here is that we just have some technical hurdles, and we'll need some cheap electricity. Missing from this discussion is an analysis of the environmental impact of recycling and the environmental impact of mining.

By no means am I making claims about how batteries will be recycled in the future, I just think we should base our policy decisions on the science. Recycling lithium batteries is not easy, since they tend to blow up. The main recycling processes either toss them in an incinerator, cryogenically freeze them, or chop them up in an inert atmosphere. Most of them recover negligible amounts of lithium, which is cheap to mine anyway.

Re: Residual Value: Electric Batteries vs. Internal Combustion Engine Vehicles

#37

Post by daveguy » Mon, Mar 27, 2017, 2:18 PM UTC

semi-extrinsic wrote: post #13

URSpider94 wrote: post #7

This is a terrible analysis. First of all, it assumes that the cost of a kWh of battery remains at today's high value. If battery costs are falling rapidly (and they are), then the value of a used battery pack will be driven down as inexpensive new packs come on the market. Second, it ignores the fact that 10-year-old packs will have a substantially higher rate of catastrophic failure than new packs, and if reliabili…

I agree it's terrible; even from TFA's opening paragraph: > if electric utilities were to pay $15,000 per battery, the battery alone in a 10-year-old Tesla would retain more value than an entire vehicle powered by an internal combustion engine (ICE). a) why would a utility pay that much ($2.2/cell) for a bunch of heavily-used 18650s when you can buy lightly-used 18650s on eBay today cheaper? b) if you look up used 20…

a) surprise. Those "lightly used" cells aren't lightly used. Have you ever bought them? Cheap eBay cells are garbage.

Re: Residual Value: Electric Batteries vs. Internal Combustion Engine Vehicles

#38

Post by intrasight » Mon, Mar 27, 2017, 2:31 PM UTC

epistasis wrote: post #16

intrasight wrote: post #15

I am of the opinion that the EV market is going to be held back until we have standard battery packs of known price, quality, and warranty. There's no good reason that this can't be taken on by some standards body. ANSI? Milspec? Please, somebody!

I think that there's still a need for significant exploration of the design space. What type of standard are you suggesting? Size? Connection? And how is that holding back anything at the moment?

Size: I'd suggest several standard sizes in multiples of 15cm (6 inches). For example 30cm cube. Connector: Should be recessed so it doesn't extend beyond size envelope. Voltage: Probably would need several. Connector should be unique to voltage. Multiple of 4.44 volts (NiMH x Li-Ion voltages).

Lack of standards holds things back when companies need to make a very large investment and need to know over what timeframe it will work. These standards could be in place for a long time. The "D" cell battery standard is over a hundred years old.

Re: Residual Value: Electric Batteries vs. Internal Combustion Engine Vehicles

#39

Post by intrasight » Mon, Mar 27, 2017, 2:37 PM UTC

tveita wrote: post #26

intrasight wrote: post #15

I am of the opinion that the EV market is going to be held back until we have standard battery packs of known price, quality, and warranty. There's no good reason that this can't be taken on by some standards body. ANSI? Milspec? Please, somebody!

It hasn't happened for mobiles or laptops, and I suspect similar reasons will prevent it from happening for cars. As long as battery life, size and weight are all important to the buyers, manufacturers would rather put in the extra customization work to get a competitive advantage.

Capitalism depends first on competition and then on competitive advantage. We need standards for modular power storage before we can have competition. Look at the competition for standard PC PSUs. Super high-quality and low cost - compared to proprietary power supplies.

Compete on quality (life, weight, cycles, etc) within the bounds of a modular standard.

Re: Residual Value: Electric Batteries vs. Internal Combustion Engine Vehicles

#40

Post by mitchellst » Mon, Mar 27, 2017, 2:43 PM UTC

The analysis assumes prices for these used battery packs are not governed by supply and demand. What happens to this analysis 5-10 years from now when the secondhand market for decade-used, 80% capacity batteries faces a supply glut, with relatively few potential buyers? As the comments here make clear, it's not altogether clear that such batteries are worth $15k now, as the paper claims. Let's say they are worth that much-- sounds like a great opportunity to build a business reconfiguring batteries for utility storage. But if you do that job well, then once your utility customers have satisfied their peak storage needs, your returning business drops to nothing, and the floor drops out on this battery market.