Optima RTS 3.7 Red Top Starter Battery 8020-255 Type: Sealed Lead Acid - Spiralcell Capacity (EN) Ah: 44 Nominal Voltage V: 12 Cold Cranking Amps (EN) CCA: 730 Reserve Capacity (BCI) min: 90 Weight Kg: 14.4 approx Length mm: 229 Length Top Cover mm: 237 Width mm: 172 Width Top Cover mm: 171 Height Excluding Terminals mm: 168 Height Including Terminals mm: 197 Extreme Vibration Resistance: Yes Fast Recharge: Yes Optima Spiralcell batteries are the optimum lead acid battery. Alternator: 13.8 to 15 volts. Battery charger 13.8 to 15 volts, 10 amps, 12-15 hours approx. Float charge 13.2 to 13.8 volts, 1 amp maximum current (All assuming a room temperature of 25 degrees C). All measurements are approximate.