I'm thinking about all types of charging (LiIon, lead acid, etc.). I get the basics.....but would really enjoy more info on the subject. Also....one thing that confuses me is how you can "overcharge" a battery...and how you can supply too much current (amps) to the battery. Since its generally said that current is DRAWN based on need, why does the battery itself not dictate the current requirement? My assumption has always been that the charger itself both supplies and draws current at the same time? Still, more info would be helpful. I bought a charger for my phone. It supplies 4.75v and a max of 2 amps. I am always wondering if that means it IS pushing 9.5 watts into the battery.....or if that means IF the battery calls for it. I ask because the "stock" charger for this phone battery is 5v and 1.0 amp, thus 5 watts. Does this mean I'm actually pumping 9.5 watts in or does it mean that the battery COULD draw that much, but probably isn't? Can anyone help me get the process of charging a battery clear in my head? Thanks!!