Thanks for that info.
For info I charged the three with a standard charger. You are right it doesn't run at all with three. Although with a multimeter i could see the damaged forth had some charge in it. I was able to hook it into bike to show the motor was ok which is what i needed to do.
Hope you can help.
I have a 48v 20" that has 1 damaged battery. I want to charge the other three, can this be done on the bike with the 48v charger or is that a bad idea?
If I get the three charged will it run (even if at lower power) just to show the motor works before I sell it?
Thanks