PVX-2120L is a 12 Volt 210 Amp Hour Maintenance-free, Valve-Regulated Sealed Lead-Acid Battery Designed specifically for Photovoltaic Systems SUN-EXTENDER BATTERY DESIGN FEATURES Copper Alloy Terminals for improved electrical connections. No exposed lead terminals. This change was incorporated to improve environmental safety and health. Threaded insert terminals are recessed to prevent short circuits across battery connections. New cover is flat top design. No protruding or exposed vent valves. Built in lifting handles. Reinforced container walls to reduce bulging. High Impact Strength Copolymer Polypropylene Case and Cover. Completely Sealed Valve Regulated Construction. Immobilized Electrolyte Non-Spillable. Maintenance Free Design Never Requires Watering. Absorbed Glass Mat (AGM) Micro-porous Glass Separators retain electrolyte. Flame Arresting Pressure Regulated Safety Valves. UL Recognized Systems Component. Positive Plates - Proprietary Lead Calcium Alloy- Negatives Plates - Lead Calcium. Low Self Discharge Rate Approximately 1 % per month at 25 C (77 F). Operate over a Wide Range of Temperatures from -40 C (-40 F) to +72 C (+160 F). Classified as "Non-Spillable Battery" for transport. Complies with DOT HMR49, Non-Hazardous Materials. Group Type: Group 4-D Dimensions (LxWxH): 20.76" x 8.03" x 8.63" / 527.4 x 203.9 x 219.1 mm Nominal Weight: 138 lbs. / 62.7 kg