The fireman lithium ion battery 51.2v (lifepo4) battery is a high performance energy storage unit designed for residential and office back up,it provides 5120kh energy,a normal 51.2v voltage and a 100ah -220ah rating with 6000-lifecycles, often featuring a wall mountable,,pentawall design to work with 48v inverter for home or office solar power systems. With company warranty.