Large Tesla Battery

SaltiDawg wrote:
That's why our Astronauts only ride space craft that have been successfully used at least for ten years. Oh, wait. lol

That's why a single aircraft costs the same as a prototype car.... Oh, wait.

brulaz wrote:
Have been reading GreenCarReports for a while now.

From their pages, it seems most original Chevy Volt batteries are still going strong after 6 years with little capacity loss. The last page of this article discusses this: Bolt-Volt battery replacement and degradation

The Nissan Leaf has not been so successful, especially in hot climates. Here's story about having to replace the battery pack after 5 years and 65K miles in Seattle: Nissan in Seattle

I suspect the difference between Leaf and Volt battery longevity is in part how the batteries are cooled (liquid vs air) and the fact that the Volt is a Hybrid, and so the battery may not be as fully discharged as often as a pure electric.

And here's some speculation on Tesla's battery longevity, which might not be that bad either:
Tesla battery longevity

Seems battery technology has been steadily improving over the last decade. And in other areas too: the new Toyota Prius has a new heat pump cabin heating system that they claim is 63% more efficent than resistance cabin heating. Toyota Prime Heat pump

Good post. We also follow the green car reports site. The heat thing was a consideration when we bought our leaf. We decided where we live it wouldn't be a problem. They changed the battery chemistry in later part of 2013 (ours is a 16) to a more heat resistant technology but I think the passive cooling of a leaf still makes them susceptible to early degradation in hot climates. It will be interesting to see what the 2018 leafs use. Passive or active cooling. I guess we will all find out on September 6 th.

Have been reading GreenCarReports for a while now.

From their pages, it seems most original Chevy Volt batteries are still going strong after 6 years with little capacity loss. The last page of this article discusses this: Bolt-Volt battery replacement and degradation

The Nissan Leaf has not been so successful, especially in hot climates. Here's story about having to replace the battery pack after 5 years and 65K miles in Seattle: Nissan in Seattle

I suspect the difference between Leaf and Volt battery longevity is in part how the batteries are cooled (liquid vs air) and the fact that the Volt is a Hybrid, and so the battery may not be as fully discharged as often as a pure electric.

And here's some speculation on Tesla's battery longevity, which might not be that bad either:
Tesla battery longevity

Seems battery technology has been steadily improving over the last decade. And in other areas too: the new Toyota Prius has a new heat pump cabin heating system that they claim is 63% more efficent than resistance cabin heating. Toyota Prime Heat pump

That's why our Astronauts only ride space craft that have been successfully used at least for ten years. Oh, wait. lol

MEXICOWANDERER wrote:
Short exposure lab tests are amusing at best. What large scale long duration public exposure reveals will be reality.

When I created a line of superior duty alternators I knew better than to chortle after only a few hundred. After the 5 thousandth, and tenth year, I breathed easier then started extolling the proven reliability of the product.

When the millionth electric car hits the road and another 5 years pass then and only then will statistics achieve truly valid status.

If Lab, mock-up, and computer simulations were that effective I would have never earned the money to buy all the toys I have, and retire comfortably at an early age. It's always fun trying to explain to the design engineers that it doesn't actually work they way they say it does. Throw in climate, and creative means of abuse end product users come up with and all bets are off as to how things will work over time. Although for the most part slow and incremental, batteries are getting better slowly but surely. The guys in the marketing and hype departments are still showing grate creativity as well.

MEXICOWANDERER wrote:
When the millionth electric car hits the road and another 5 years pass then and only then will statistics achieve truly valid status.

In five years the chemistry and design will have changed...

Short exposure lab tests are amusing at best. What large scale long duration public exposure reveals will be reality.

When I created a line of superior duty alternators I knew better than to chortle after only a few hundred. After the 5 thousandth, and tenth year, I breathed easier then started extolling the proven reliability of the product.

When the millionth electric car hits the road and another 5 years pass then and only then will statistics achieve truly valid status.

Searching_Ut wrote:

John & Angela wrote:

2oldman wrote:

road-runner wrote:
Can the Li battery be run all the way down without shortening its life? And I wonder how good its life is, in terms of discharge cycles, compared to a golf cart battery?

No. Mfr says 80%. 3-5k cycles.

And further to this you can google a survey on how many deep cycles the average EV driver cycles their battery although i don't recall if it mentions how deep they cycle. Anyway on average users charge about 125 times per year. For us it's about 80 and we tend to recharge at the 35 to 40 percent point. We usually charge to arround 90 percent but on longer trips we charge to 100 percent the night before. One down side of charging to 100 percent is the reduced Regen braking you get at 100 percent. This is because there is no where for the power to go until the percentage of charge drops a bit. A curiosity of electric vehicles.

The fact most people won't cycle the battery anywhere near 80 percent on a regular basis is what allows GM to bet that the battery they are putting in their Bolt will be able to maintain 60 percent capacity at the 8 year mark. Time will say whether or not this costs them. As for charging to 100 percent, all lithium variants I've seen age deteriorate quite a bit faster if stored in a fully charged state. If you're not going to start using it right away probably best to only charge to 95 percent or so.

Regarding the question on cycle depth and battery life, none of the batteries I've seen the independent data on have been able to meet the criteria of still being able to reach 80 percent of original capacity after 2000 cycles of 80percent. That is of course on a bench in a controlled temperature environment. Like a lead based battery, depth of discharge, temperature and current rates for charge and discharge can have negative effects, but for the most part they aren't as pronounced as what you see with lead acid. It's not unreasonable to expect twice the cycle life out of a lithium based battery cycling through 80 percent as what you would get from a quality lead acid being cycled 50 percent. Unfortunately, like with any new technology real data is hard to come by, and user perceptions tend to be terrible.

. I agree. A lot of this will be wait and see. Our one vehicle is almost three years old and we seem to be down about 3.2 percent total. It will be interesting to see how it looks in 7 to 10 years.

John & Angela wrote:

2oldman wrote:

road-runner wrote:
Can the Li battery be run all the way down without shortening its life? And I wonder how good its life is, in terms of discharge cycles, compared to a golf cart battery?

No. Mfr says 80%. 3-5k cycles.

And further to this you can google a survey on how many deep cycles the average EV driver cycles their battery although i don't recall if it mentions how deep they cycle. Anyway on average users charge about 125 times per year. For us it's about 80 and we tend to recharge at the 35 to 40 percent point. We usually charge to arround 90 percent but on longer trips we charge to 100 percent the night before. One down side of charging to 100 percent is the reduced Regen braking you get at 100 percent. This is because there is no where for the power to go until the percentage of charge drops a bit. A curiosity of electric vehicles.

The fact most people won't cycle the battery anywhere near 80 percent on a regular basis is what allows GM to bet that the battery they are putting in their Bolt will be able to maintain 60 percent capacity at the 8 year mark. Time will say whether or not this costs them. As for charging to 100 percent, all lithium variants I've seen age deteriorate quite a bit faster if stored in a fully charged state. If you're not going to start using it right away probably best to only charge to 95 percent or so.

Regarding the question on cycle depth and battery life, none of the batteries I've seen the independent data on have been able to meet the criteria of still being able to reach 80 percent of original capacity after 2000 cycles of 80percent. That is of course on a bench in a controlled temperature environment. Like a lead based battery, depth of discharge, temperature and current rates for charge and discharge can have negative effects, but for the most part they aren't as pronounced as what you see with lead acid. It's not unreasonable to expect twice the cycle life out of a lithium based battery cycling through 80 percent as what you would get from a quality lead acid being cycled 50 percent. Unfortunately, like with any new technology real data is hard to come by, and user perceptions tend to be terrible.

Peak energy use varies according to regions within the USA. The aforementioned re-pump reservoir system in California pumps water back uphill during demand slump in the early morning hours then lets it fall during peak consumption 2:00 PM - 8:00 PM

My little toad has a 1-ton rated belt-driven A/C. During 35c weather the unit does not cycle - it is on full time. I would hate to think how much electrical energy it would take to spin that (small) Nippondenso compressor.