• The power supply needed to recharge a battery depends a great deal on the internal chemistry of the battery. • Grandcell Rechargeable Alkaline batteries are composed of a different chemical system from NiCd and NiMH batteries, and hence require different power parameters when it comes to charging. • A NiMH / NiCd charger applies constant current without any voltage regulation. A Rechargeable Alkaline would leak/vent in this type of charger, making the battery useless. The venting results from a pressure build-up caused by the electrolysis of the electrolyte in the Rechargeable Alkaline battery.