I think there is something odd going on with the batteries on these. I haven't noticed what you have seen, but I do notice that the battery drains itself when not in use more rapidly than I would expect. For me, if i charge to 100% and then leave it for a few days, it seems to lose a few percent , then stabilise. Maybe that's the bms doing it's thing to protect the battery?I’ve noticed the same when just leaving my bike plugged & charging overnight. It’ll say 100%, but will go through the first 10% super fast.
Then doing the same route after charging for 4hrs, I get much better range.
People tell me I’m wrong and I’m no electrician, but I repeat the same local route and see a 15% variation.
I think it’d be ideal to use a timer so power to the charger cuts off just after a full charge.
It wouldn't surprise me if Theres another battery firmware update soon, there's something weird going on.