How are Motorcycle Batteries Rated?
The amp/hour (AH) capacity is the basis for rating motorcycle batteries. For example, a 12AH battery can produce one amp of current flow for 12 hours, or two amps for six hours. In order to calculate the amount of time needed to use up a fully charged motorcycle battery by turning the lights on, we have to take power in watts, and divide it by voltage, which gives us the current draw in Amps. Therefore, a 72 watts beam and tail together, divided by 12 volts equals a 6-amp draw. So in 2 hours, the 12AH battery is dead.
Checking Motorcycle Battery:
If you decide to check if your new motorcycle battery is done correctly, follow this actual factory-recommended service procedure.
If the battery is not a maintenance-free type which doesn’t have a vent tube, unwrap the battery, unkink the vent tube and snip about a half-inch off the end. Fill it with electrolyte midway (between the high and low level markings on the case) and leave it undisturbed for one or two hours. Remember, the battery will still be at only 65% of full charge at this point. Add electrolyte again if required.
If your battery is a...