Just got my new charger.
It is a no-name 48V/4.5 amp auto-charger.
I am recharging right now. The killawatt says its' only pulling 108 watts, so I don't think it's putting out too many amps. Maybe I need the batteries run down a little deeper for it to want to charge faster?
I will have the numbers tomorrow on the energy usage of my first run with the new charger.