12.0 V 4000mAh Powerful Battery Pack made of 10 x D size High Quality Ni-Cd cells with 14 Gauge wire. Features: 1．Dimension: 160 x 60 x 66 mm. 2．Weight: 3.4 Lbs. 3．Designed for Emergency Lighting Power, however, can be used for any DC 12V back up power application. 4．At 500 mA discharge current, the power pack can provide 8hrs of running time. 5．Rapidly charges 6．Long cycle life 7．Recharge up to 500 times. 8．Since NiCd batteries have lower self-discharge than NiMH, it is suitable for use as a storage battery for solar power. 9．You can use our 7.2V-12V smart charger to charger this battery pack.