k, I ran the 48V 18AH pack down to 2 bars today, and plugged it in. this is the charge curve, in watts. Divide watts by 12V to get amps on a DC system. I note that the light on the charger went from red to green about when that 'tick' is at about 8:10pm, about 3.5 hours after plugging it in, but it still seems to be charging a little. it will eventually shut off.