EBC Universal Smart Charger - 52v 2 amp Lithium Ion Battery
52V 2A Smart Charger / Selectable charge voltage to prolong battery life - selectable 80%, 90%, 100% charge voltage /90~264VAC Universal AC input / Charge voltage 58.8 / AC Plug: USA / DC Charge connector: DC 5.5mm Barrel/ Power: 2 amps / Protection function: / Overload / Over voltage / Over temperature / Over current / Reverse polarity / Power off or trickle after finished charging.
This 2 amp charger will charge the 52v Shark battery in 4-6 hours. Less than 8 hours if the battery is totally drained.
For more info on extending battery life click here.