Yeah it’s interesting: it varies by OEM. Volvo and Lucid, for example, allow 100%, or nearly 100%, charging, and strongly advise that owners rarely do so. That allows them to advertise the longer range that is only possible by accessing capacity that would be buffer in other vehicles. The usable capacity is close to the total capacity with little to no buffer built in. Others have various amounts of buffers, so what is shown as fully charged is actually 83% or a bit more or less. So their “full” charge is the former’s 80% level. And few of them seem to be wonderfully transparent about the size of their buffers.
What brand is your vehicle?
I readily accept that time near true 100% accelerates battery degradation. I’m just not finding anything that verifies the size and edges of the, for lack of a better phrase, sweet spot. I think that probably @Fear_Itself’s approach is as good as timing it to be ready just before the morning commute, if in reality charging to 80%. But I would love to hear that someone else knows it.
@puzzlegal most of my CMax miles were electric also, especially when the battery was fresh. 19 miles covered my daily commute. I got frustrated when it went into “engine maintenance” mode, burning gas because its ICE needed to run a minimal amount.