About this item [Work For VTOMAN Only] The FlashSpeed 1500 Extra Battery can be only used for VTOMAN FlashSpeed 1000 and FlashSpeed 1500 Power Station. [Double Your Capacity At Once] VTOMAN FlashSpeed 1500 Extra Battery has a large capacity of 1548Wh. It can expand the capacity of FlashSpeed 1500 power station from 1548Wh to 3096Wh, or expand FlashSpeed 1000 from 828Wh to 2376Wh. Accordingly, whether camping, traveling, or at other times, this product bundle allows you to carefree enjoy your time.(Kindly note that the FlashSpeed 1500 Extra Battery cannot be used alone, it has to connect with VTOMAN power stations to work) [LFP Battery with BMS] The FlashSpeed 1500 Expansion Battery is built-in durable LiFePO4(LFP) battery that features a lifespan of 3000 full cycles to 80% of its original capacity. LiFePO4 is also much safer and more durable than NCM batteries. Also the built-in BMS provides multiple protection for the battery, such as over-charge protection, over-discharge protection,