I have never realy understood batteries. To me they should never fail and yet they do. They seem to fail during cilmatic weather changes (hot to cold,cold to hot,wet to dry, dry to wet.)
But why do they fail? It is a chemical reaction between zinc,lead and acid. I suppose if you let the darn thing draw down far enough it would no take a charge. But I have never killed one for that reason. What I mean is that I have allways been able to recharge them on a trickle charger left on for 24 hours if it was only discharged.

I didn't do it, no one saw me do it, you can't prove anything! "Bart Simpson"