Sterling Power battery to battery charging system - DC to DC smart battery charger, marine grade DC powered charger 12v to 48v
RIDE 1 UP Electric Bike HD 48 Volt Battery Charger Output is 54.6 Volts | eBay
Amazon.com: SuperHandy Heavy Duty Lithium Ion Battery Charger 100-240V AC 50/60Hz 2.5A (Charger ONLY) (for SuperHandy 48V 2Ah/4Ah Batteries Used n Utility Cart, Wheelbarrow, Mobility Scooter, Air Compressor) : Tools & Home