Charger Light Stays Green When Connected To Battery

Hello,

I am having issues with a lectric xpress 1 where the battery is able to power the bike, but when connected to the charger the light on the charger never goes from green to red. Meaning the battery isn't being charged. I have tried
-checking the fuse in the battery

-replacing the charger

-cleaning the input puns on the battery

I would like to avoid buying a new battery because they are rather expensive (especially if i dont know what caused the failure). Anyone have an issue like this before?