The ATEN UPS Internal Battery Pack comes with a hot-swap design, allowing uninterrupted operations during battery replacement to ATEN UPS systems. It ensures stable power supply and offers easy installation, bringing users hassle-free management to their power equipment. Note: When the battery pack is not in use, please recharge it for 4 ~ 6 hours every 3 ~ 6 months. Electrical Nominal Output Voltage 36V Battery Battery Type Sealed Lead-Acid Battery Size 9AH Battery Quantity 3 Physical Properties Dimensions (L x W x H) 25.77 x 21.37 x 6.66 cm (10.15 x 8.41 x 2.62 in.) Weight 8.10 kg ( 17.84 lb ) Color Black Environmental Temperature (Operating / Storage) Operating: 32 – 104 °F (0 – 40 °C) Storage: -15 – 45 °C Humidity (Operating & Storage) 0–95% Elevation (Operating / Storage) Operating: 0-10,000ft (0-3,000meter) Storage: 0-50,000ft (0-15,000meter) Note For some of rack mount products, please note that the standard physical dimensions of WxDxH are expressed using a LxWxH format.