The HR series VRLA battery is designed for heavy loads, has high power and a long service life in float (buffer) mode. The HR series battery has 30% more power than standard series and is used in backup power systems with UPS. Specifications: Number of elements: 6 Voltage: 12 V Nominal capacity: 5.5 Ah at 20-hour discharge to 1.75 V per element at 25 ° C Weight: 1.64 kg (Tolerance ± 5.0%) Internal resistance: 30 mOhm Terminal type: F2 Maximum discharge current: 55 A (5 seconds) Short-circuit current 280 A Shelf life: 10 years Maximum charging current: 0.55 A Test capacity: C10 5.1 AHC20 5.5 AH Charging voltage Float Voltage: 13.7V~13.9V@25°C Temperature Compensation: -3mV/°C/cell Cycle Charge Voltage: 14.6V~14.8V@25°C Temperature Compensation: -4mV/°C/cell Operating Temperature Range: Discharge: -20°C~60°C Charge: 0°C~50°C Storage: -20°C~60°C Normal Operating Temperature Range: 25±5°C Case Material: A.B.S. UL94-HB, UL94-V0C Self-Discharge: RITAR Rechargeable Battery Regulated Lead Acid (VRLA) batteries can be stored for up to 6 months at 25°C and then recharging is recommended. The monthly self-discharge rate is less than 3% at 25°C. Please charge the batteries before use. Please note! Failure to comply with the voltage and current specifications may damage the battery and void the warranty.