How Long To Charge Motorcycle Battery At 6 Amps. I see multiple problems here. Charging a battery on a motorcycle is different from working on your car battery.
If you were going to use the 300ma charger then the motorcycle battery would take around 8 to 12 hours to be fully charged. Amperage rating of the charger is 6 amp. A battery charger that provides 6 amps for each hour that it is connected to your battery will be able to charge a 48 amp hour battery in about eight hours.
Using a 2A charger on a motorcycle battery -- I would suggest 125A or lower 2.
Charge for a full 8-12 hours. As you can probably guess then the Amp rating of both your charger and the battery is a major part of what determines how long it takes to charge your motorcycle battery. Motorcycle and scooter batteries are 12 volts just like car batteries so they use the same chargers. Battery Charging Basic Rule.
