Sounds like you’re killing your batteries by not using a charger that is provided by the manufacturer. If you need a charger replacement, I would get the exact one that came with the scooter. Otherwise, you could damage your batteries which are expensive. I would recommend finding the GoGo scooter model on our site, then looking at the specs to see how many amps the charger is that comes with it.
After you’ve identified how many amps your charger is supposed to be, you should know if you’re killing your batteries or not. I imagine 3 amps is the highest you’ll be able to go since all GOGO’s are travel units with relatively small batteries.