This SAE Aerospace Recommended Practice (ARP) describes two general types of Ground Support Equipment (GSE) battery chargers. The conventional industrial battery charger typically requiring up to 8 hours to recharge a 100% discharged battery, hereafter called Conventional Charger. The other type a fast battery charger typically used as an opportunity charger for ground support equipment, hereafter called Fast Charger. Recommendations that apply to both types will refer generically to charger.