battery charge

Hi! I’ve been charging my 17,5 Ah Panasonic battery with not original 4A generic charger from Amazon, instead with 2A original charger. The battery can’t be charged anymore with any charger. Nothing happens when I plug in the charger. In the last few weeks I had to plug the charger (2A or 4A)...

I have an EasyMotion Evo Street urban electric bike - 2015-2016. Until a few days ago, it as has worked perfectly. Now, when I turn on the handlebar controller, it starts up normally, but shows the battery at zero level. In this state, I don't get any pedal assist, and cannot change the pedal...