This Gama Sonic 3.2 Volt IFR18500, 800 mAh, 1-cell replacement LiFeP04 battery pack is for Gama Sonic solar light fixtures in the GS-139. Specifications: Nominal Voltage: 3.2V Size: 18500 Capacity: 800 mAh Chemistry: Lithium Phosphate (LiFePO4) Max Charging current: 1.5 Amp Max Discharging current: 7 Amp Energy density: 9.6 wh Brand: Portable Power Included Qty: 1 Dimensions: Length: 65 mm (2.56") Width: 36.5mm (1.5") Diameter: 18 mm (0.71") Weight: 85 g (3 Oz) Features: Fits GS-139 series lamps. Lithium Phosphate battery lasts up to 3 years Plug in clip allows for easy replacement in lights Superior high temperature & storage performance make LiFePO4 the most suitable one for Li-ion battery positive material Longer than 1000 cycle life is more suitable for application use. Light weight and high energy density. Installed IC chip will prevent the battery pack from over charge and over discharge. It helps protect battery chemistry integrity and prolongs battery life. Highest Safety of all Lithium batteries Includes 1 Male adapter