Onbypass wrote:I called Nissan to ask about this. I've heard posts from folks using the 20%-80% rule, others that time is perfectly so that it only stays at 100% for a short while, and other that charge all the time without any regard to anything!!!!
The first two aren't incompatible. If possible, try to keep the battery between 20-80%, but if your range needs require more than 80%, then minimize how long it stays at a high level by timing the charge to end as close to your departure time as possible. The issue isn't charging to 100%, it's charging to 100% and letting the car sit like that for an extended period. Nissan prior to 2014 had a "Long Life Mode" that automatically shut off charging at 80% but they took it away for the US and Canadian market.
I have a 2018 Leaf, so the battery chemistry is probably different from the 30 kw/h versions.
It may be different, but one important factor is it may not be any better, and could be worse.
For example, the 30 kWH batteries seem to degrade faster than the 24 kWH ones used in the 2015's and some 2016's. It's too early to say if the 40 kWH in the 2018's will do better or worse than any previous Leaf battery.
So....I called Nissan and asked them. They said that high heat is the most important factor when talking about battery longevity. They said that if it's hot out, park in the shade. Also, turn on the A/C in the car 5-10 minutes before you get into the car, when it's outside. It doesn't completely cool the battery, but it helps.
As the Leaf doesn't have any kind of active cooling system for the battery, turning on the A/C wouldn't help at all. The Kia Soul EV (at least the original -- don't know about the new model just announced at the LA Auto Show) does direct cabin air to the battery, but from what I've heard it hasn't made the battery last any longer than the Leaf's.
They also said to let it run down to 30-40%, and recharge then. 20%, 30%, 40%.....those levels ( In other words, don't drive to the store and recharge it when it's 90%! Also, don't let it run down to 5% either!!!)
The theory is that it reduces the number of charging cycles.
There's also a theory that frequent but shallow charging cycles are better for your battery, as it heats up the battery less. I do agree with them that you shouldn't "top up" if the battery is already in the 90's % and to not let the battery level drop that low.
When it's low, I am going to charge it to 100%, and I am not going to time it, unless I switch to a power plan that is less expensive overnight.
Well, I hope you don't have a big range need, because constantly charging to 100% and letting it sit for long periods like that is definitely not good for the battery. Even Tesla with their active battery TMS doesn't recommend constantly charging to 100%.