Byris
Re: chargers...you might also look at the Multiplex charger. It will do NiCd, NiMH, LiPo, and Pb (lead acid, like the one you probably have for your starter). It operates off any 12 volt source, but has leads with banana clips connected to alligator clamps. Thus away from the field you can simply disconnect the alligators and plug the bananas into a 12 volt power supply. There are a number of these available with posts for the bananas for under $40.