WetEV
Well-known member
surfingslovak said:Interesting. If you had said that couple of years ago, you would have likely witnessed something akin to a public lynching.WetEV said:from about 500 to about 4000 full battery cycles to 70% capacity. This is from 37,500 miles to 300,000 miles, based on 75 miles per full battery cycle.
I know. Yet well known experts, which I am not on either count, said much the same thing in the press. People didn't want to listen???
surfingslovak said:Perhaps, but as SierraQ said above, you are giving an insanely wide range of cycles.
The range of cycles isn't insanely wide. Consider climates from Prince Rupert, Phoenix, AZ. Then work out the Arrhenius ratio of lifetimes: perhaps 4:1 right there. Add self heating under moderate driving and charging(fairly low, longer battery life) to self heating under high discharge rates and/or recharge rates (fairly high, shorter battery life): perhaps another 1.5:1. Add some different cycles (100% to 10% or 70% to 30%, narrower cycles give longer battery life): perhaps another 1.3:1. Toss in a bit more for keeping the battery at 100% and other behaviors. Stir in a bit of other stuff. Looks like a wide range to me. Of course, I'm not a real battery expert. If anyone knows more, correct me.
On the other hand, you might assume that Nissan was being pessimistic in the battery life assessment like Nissan was in the range assessment. Perhaps exactly the same. In which case I'm being way too optimistic.
surfingslovak said:The manufacturer gave the purchasing public assurances that the battery will last the life of the vehicle, and that it will withstand a wide range of climates seen in the US. A TMS was specifically called out as unnecessary. Perhaps it was a bit naive to believe that, but for you to come forward in the wake of the Phoenix fiasco, claim that you knew it all beforehand, and anticipated some batteries reaching EOL in less than two years and 40K miles sounds a bit over the top.
I do fault Nissan on this.
Did you listen to Elon Musk at all? If you didn't listen to him, why would you have listened to me?
http://www.plugincars.com/tesla-ceo-rips-nissans-battery-technology-says-its-primitive-50527.html" onclick="window.open(this.href);return false;
surfingslovak said:Watch the pack voltage, it's a source of truth, and it indicates that not all of the capacity decline we see is imaginary.
I agree with your assessment that this isn't just a software bug.
surfingslovak said:I disagree. A lot of the technology in the Leaf was and is still treated as something proprietary and of great value. Not to be shared with the competition, and definitely not with the ignorant public. Many of us wanted to see something as simple as a cycle life data sheet from AESC. I dare you to find one. Instead, we were left scratching our heads and looking for shreds of information on comparable products and components, which is not exactly easy to do. The same thing can be said of thermal performance. It's fairly standard procedure to put cells in a temperature controlled chamber and see how different temps affect cycle life. And again, this information on AESC cells is nowhere to be found. The list goes on.WetEV said:The information needed to make an informed purchase was out there. There was an excess of optimism, there is now an excess of pessimism. There is a point to having a BEV like the Leaf (Li ion with no TMS) in much of the country.
Again, I do fault Nissan on this. More information is needed, and Nissan better realize that giving more information at this point reduces their future liability.
There is a point to a BEV without TMS. Lower cost, less to go wrong, just better keep it cool in other ways or expect to replace battery packs early. Nissan did not sell the Leaf this way, which is too bad.
surfingslovak said:I'm not a proponent of some of the more drastic measures suggested on the forum, but I do believe that this issue needs the attention it deserves. It can easily become the most important problem the Leaf program has faced. It could have a ripple effect on the nascent EV industry as a whole. There also needs to be more openness and some give-and-take between manufacturers and early adopters. We can help each other, and are starting to realize that, but it's not enough. That said, I absolutely agree with Tony and others that there needs to be new regulation for EVs. I suspect that's the only language the auto industry understands, and they will get it right.WetEV said:Yes, a full court legal press might maximize your payout, and will surely maximize the lawyer's pay. But is that a good thing? If it convinces other car companies to not offer a comparable BEV, is it a bad thing? I guess the answer depends a little on point of view, and on the time period, and what costs you consider.
I'm mostly in agreement with you. I've put this comment in to suggest that some of the more drastic measures are counterproductive. Nissan had best do something like the following (which I've said before):
1) Convert sales to leases on request, at least for hot areas. Maybe not free, but not high cost.
2) Allow for early lease exit without major loss to the customer. I note that there has been one case of this so far.
3) Give more information about the battery life expectation.
Regulation needs to be a requirement to put some basic battery pack life information on the EPA label. Perhaps just number of cycles to 70% at some standard temperature, rate of charge and discharge and cycle depth. The temperature might be the upper limit temperature of the TMS if there is a TMS. Some comment on the TMS system or lack there of is needed as well on the EPA label. There is a point to a BEV without TMS, but need to make sure people know what they are buying.