Howard Lighting HL0202-BATT Rechargeable Replacement Battery Battery for Hl0202 6V, 4.5Ah, sealed Lead acid, maintenance-free, rechargeable battery Internal solid-state transfer switch automatically connects the internal battery to lamp heads for minimum 90-minute emergency illumination Fully automatic solid-state, two-rate charger initiates battery charging to recharge a discharged battery in 24 hours