Lithium-Iron Phosphate Batteries are perfect fit for outdoor solar powered equipments. The battery offers a longer life cycle,  and its wide operating temperature range provides an outstanding performance in efficiency and sustaining energy while charged by solar powered devices. Rechargeable Battery for solar lights   Features High recharge cycles life of more than 1000 times.  Wide operating temperature range : The battery   is capable of operation in a wide temperature range   from -10oC to +60oC.  Excellent safety: The batteries passed all safety test    of crushing, altitude simulation, short circuit, impact,   nail picking and over discharge test without leak,    explosion or fire   Specifications Chemistry: Lithium Phosphate Voltage: 3.2 Capacity: 400mAh Size: 14430 (same diameter of AA but shorter in length)