The chemistry of E-Series batteries is LiFePO4, it has about 3 times the energy density and 70% less weight than equivalent capacity lead acid batteries. In addition, the E-series batteries have a life of up to 3000 cycles, whilst typical lead acids can only reach 300 to 500 cycles. Compatible with the Spirit series, Navy series and Pod Drive systems Real-time battery monitoring, easy access to battery operating status Connectors able to be installed by one hand, no special tools required Does not include battery charger. E Battery charger sold separately. PRODUCT SPECS: E60 E163 Capacity 3072 Wh 8345 Wh Max Continuous Discharging Current 70 A 150 A Rated Voltage 51.2 V 51.2 V Final charging voltage 57.6 V 57.6 V Cut-off voltage 41.6 V 41.6 V Battery Life 3000 Cycles at 80% DOD 3000 Cycles at 80% DOD Series Connection Not allowed Not allowed Parallel Connection Up to 16 Up to 16 Charging Time 2.7 hrs 7 hrs Weight 33 kg 76 kg Dimensions 51.2 x 29 x 30 cm 47 × 29.5 × 49.5 cm