I have a Lil' Rascal electric scooter and the batteries died. They were 12v, 34 Ahr batteries. Two of them. I had some 12v, 20 Ahr batteries and put them in there, and the scooter is running fine, but I'm afraid when I plug in the charger, they are going to overheat and explode. If the charger is meant for 2, 34 Ahr batteries, and they are now 2, 20Ahr abtteries, will that hurt anything? Thanks. No the only difference will be how long it will run on 1 charge. The 34Ahr will last 50 percent longer than the 20Ahr The amp hours determines the length of power and the 12 v is the amount of voltage that is needed and since they're both 12v then it is safe to charge. you shoulda got a hoveround..it would have taken you all the way to the grand canyon.. It shouldn't hurt. I use to have to unplug my charger so it didn't overcharge the batteries because it wasn't a smart charger.~ | 