LeftieBiker said:
Are you saying that we here at MNL are telling people never to charge a Leaf to 100%?
Maybe so. I don't recall who, if any.
LeftieBiker said:
Because someone just claimed that, and you seem to be supporting him or her in that claim. Why, I have no idea.
I'm just presenting to the OP what the manual says and examples of this debate given the various li-ion battery literature, Nissan's hints/guidelines, people's various beliefs, etc.
For me, I generally only charge to 80% except for the few times where I prefer to have more than 80% or the full 100%. My commute's short enough (no more than ~13 miles each way) that charging to 80% is more than enough to go home and make it back to work, where I can charge for free. I live in and work in hotter parts of the SF Bay Area. So, unfortunately, my battery doesn't have anywhere close to as good as the Seattle area, Oregon, and cooler cities in the Bay Area like SF, Pacifica, Half Moon Bay, etc.
On weekends, to avoid having to charge much/at all at home, I do break the rule and the car might be at as high as 90 to 92% (per dash display) SoC for 12 to 16+ hours. This is the result of charging to 100% at work and often using free public L2 on the way home/on the weekend. Unless I hypermile, I can't arrive home w/any higher than 92%.
I don't care generally about the "20%" guideline but I've personally never left my car at below 10% for more than 6 or 7 hours, nor do I run it that low regularly. I'm not really convinced that there's any issue with low SoC beyond what I quoted in the manual. I've never run my cars to turtle yet but wouldn't want to leave it in turtle (if I did) for more than a day.
FWIW, some have attributed the gen 1 Volt's apparent minimal degradation to its battery thermal management and only using a narrower SoC range in the middle of the battery than the Leaf typically does. Teslas also have battery thermal management and Model S reportedly suffers from minimal degradation probably due to this, many trips resulting in not very high DoD and I suspect many owners don't often charge to 100% as they (AFAIK) have some sort of charge limit % UI. Looks like they allow 10% and 2% increments.
Examples of literature: (not that some of the data/discussion may not be of the variant the Leaf uses)
http://batteryuniversity.com/learn/article/types_of_lithium_ion
http://batteryuniversity.com/learn/article/how_to_store_batteries
http://batteryuniversity.com/learn/article/types_of_lithium_ion