[alanw]

Originally Posted by beef78

Will using a car battery charger hurt a smaller 12 volt battery?

Generally, yes it will hurt a small battery. Unless your charger has a low enough amp setting, car chargers are meant for bigger capacity batteries and put out too many amps for our little AGM batteries.

I think the rule is to use a charger that puts out at least 10% but no more than 25% of the batteries rated AH, so for example use a 2500ma max output charger with a 10ah battery.

I use one of these G3500 Genius chargers for my 12ah batteries
http://www.geniuschargers.com/G3500

And I'd use something like the G1100 Genius (or equivalent) for a 10ah battery