E Battery Chargers 110VAC are designed to specifically work in conjunction with the E batteries manufactured by e Propulsion. Selection of the charger current rating is determined by the size of your existing battery bank and required time for recharge. The higher the current rating of the charger, the quicker the recharge time.
For example a E 40 battery that is rated at 2048 W hours (2048W-Hr/48VDC= 42A-Hr) which was discharged to 20% of its 42A-Hr rating would require approximately 34 A-Hr to recharge. If you had a 10A charger, it would take approximately 3 1/2 hours to recharge the battery to full. If you had a 20A charger, the charge time would be half of that or approximately 1-3/4 hours.