Who exactly advises people "to not charge above 80%"?
The '13 Leaf manual (last US model year to have a setting to charge to 80%) does.
OP can download a copy from https://owners.nissanusa.com/nowners/na ... nualsGuide
and search for 80%. It's all over the place, besides referring to 80% mode as long life mode and "improves battery longevity".
Some bits from page EV-24
To maximize vehicle range, NISSAN recommends
using the default setting, long distance
mode (100% charge). To maximize the battery’s
useful life, use the following driving and charging
habits where possible:
Avoid sustained high battery state of charge
(caused, for example, by frequently charging to
100% state of charge and/or leaving the battery
above 80% state of charge for long periods of
• Allow the battery charge to be below at least
80% before charging
Unfortunately, Nissan has never publicly provided us with any battery degradation info for 80% vs. 100% or any other % SoC vs. temp and/or temp. Nor have they said how much better it is (if any) to only charge to 80% or if it's bad to run below 20% or whatever %.
The only warnings I quickly found about low SoC are along these lines:
To prevent damage to the Li-ion battery:
Do not leave your vehicle for over 14
days where the Li-ion battery available
charge gauge reaches a zero or near
zero (state of charge).
Avoid leaving your vehicle for over 14 days
where the Li-ion battery available charge gauge
reaches a zero or near zero (state of charge).