> People who have bought them abroad are sometimes advised to keep the battery between 20%-80-90% full.
You want to keep batteries roughly in that range to maximise their lifetime health. That doesn't mean the battery will explode if you do otherwise once in a while e.g. you charge limit the car to 80% for your daily drive and before a big trip you charge to 100%.
Route planners will generally keep you in that band anyway because charging speeds fall off a cliff as charge exceeds 80~90% (depending on the manufacturer's usable % standard), and it's rarely worth wasting 30mn charging to full to save 5~10mn extra at the next stop (the same occurs to a lower extent at very low states of charge, plus you want some spare, so the lower 10% are generally treated as a reserve).
Well, stopping the car at 40% (20% for Li-ion) capacity or alternatively at 0% with dead batteries, I know what I prefer (ideally there would be an option for emergencies, perhaps disabled in rental cars ;-} .
You want to keep batteries roughly in that range to maximise their lifetime health. That doesn't mean the battery will explode if you do otherwise once in a while e.g. you charge limit the car to 80% for your daily drive and before a big trip you charge to 100%.
Route planners will generally keep you in that band anyway because charging speeds fall off a cliff as charge exceeds 80~90% (depending on the manufacturer's usable % standard), and it's rarely worth wasting 30mn charging to full to save 5~10mn extra at the next stop (the same occurs to a lower extent at very low states of charge, plus you want some spare, so the lower 10% are generally treated as a reserve).