8 Lessons about battery health

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ericy

ericy

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They did a systematic analysis of a number of EVs to come up with information about battery health, and how fast it degrades with time.

https://electrek.co/2019/12/14/8-lessons-about-ev-battery-health-from-6300-electric-cars/

I don't want to quote the whole article, but there are a couple of takeaways. Liquid cooled batteries do better. And cars with a larger SOC buffer will do better. Cars in really hot climates will do worse.

Frequent DCFC makes it worse, esp in hot climates. Which makes me wonder how much of this problem is really just thermal.
 
Nice article. Just we are often limited to what the car tells us or allows us to use. Worse, some of the EU/LG-CHEM cars suggest either really poor performance or ‘sand-bagging’. Given the history of diesel and other too good to be true claims ... well I would prefer independent lab analysis.

Color me skeptical of vehicle reported metrics. For example, Tesla has temporarily increased range of their cars in a hurricane evacuation area ... a good thing. In trading EV battery life vs owner life, Tesla makes the moral choice.

Bob Wilson
 
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gooki said:
I thought this was only for cars that we're sold with software locked batteries, not all Tesla's.
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I've been using a new tool, 'scan my tesla', which reports both the owner viewed and internal battery SOC. Our other car, a 2014 BMW i3-REx, has been listed as having a 22 kWh battery but usable is only 18.6 kWh in mine and most good-shape BMW i3.

Bob Wilson
 
I do suspect that high temperatures play a major role in degradation. I do use an air cooled 2018 4kwh Leaf. This is the one with "Rapidgate" not so fast L3 charging. On a low SOC it charges at around 48kw and starts tapering sharply after 50% SOC. I think Nissan did this to reduce L3 heating but it may be a little
overkill. I've only been able to add 2 heat bars at the most by L3 from 20% to 80%. This winter I've only added one bar per charge which I welcome as it brings that battery closer to the "goldilocks zone".

I've gone out an hour after arriving home in cold temps and found the battery had not yet lost a heat bar. The thing you have to watch Leaf packs is that they take a long time to cool down. So, if you're wanting to do a long trip with more than 2 L3 top ups I can see where you could get into overheating if you get the software upgrade. One of my tricks is that two 15 minute stops will heat the battery less than a single 30 and give more range because of the taper.

As a result of Inside EVs I pay very close attention to my battery temp. We only get stinking hot in South East Ontario for two months of the year and I am extra vigilent during that period. So far. So good. I will keep readers posted as the car (and I) get older.
 
Paul K said:
I do suspect that high temperatures play a major role in degradation. I do use an air cooled 2018 4kwh Leaf. This is the one with "Rapidgate" not so fast L3 charging. On a low SOC it charges at around 48kw and starts tapering sharply after 50% SOC. I think Nissan did this to reduce L3 heating but it may be a little
overkill. I've only been able to add 2 heat bars at the most by L3 from 20% to 80%. This winter I've only added one bar per charge which I welcome as it brings that battery closer to the "goldilocks zone".

I've gone out an hour after arriving home in cold temps and found the battery had not yet lost a heat bar. The thing you have to watch Leaf packs is that they take a long time to cool down. So, if you're wanting to do a long trip with more than 2 L3 top ups I can see where you could get into overheating if you get the software upgrade. One of my tricks is that two 15 minute stops will heat the battery less than a single 30 and give more range because of the taper.

As a result of Inside EVs I pay very close attention to my battery temp. We only get stinking hot in South East Ontario for two months of the year and I am extra vigilent during that period. So far. So good. I will keep readers posted as the car (and I) get older.
Click to expand...
Leaf spy is an excellent tool for monitoring pack temperature.
 
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