Harley-Davidson motorcycles require a well-maintained battery in order to function properly. Unfortunately, since most Americans view motorcycles as recreational vehicles, most Harleys are weekend warriors that spend more time in the garage than on the road. This can degrade the battery’s charge and cause many problems, ranging from a hard to start condition to poor engine performance. Using a multimeter and a few basic tools, you can identify a faulty battery before it becomes a real problem.
1. Locate the battery. Sportster and Dyna models have their batteries behind the left side frame cover or in a box mounted on the side of the frame while the other models conceal the battery beneath the rider’s saddle.
2. Access the battery. A Sportster’s side cover can simply be pulled off of the frame by hand, exposing the battery. The battery box on a Dyna model can be opened by hand as well. Remove the seat to access the battery on Softail and Touring models. Locate and remove the three Allen bolts that secure the seat to the frame using an Allen wrench. Lift the rear of the seat upwards and pull it towards the rear fender to disengage the seat from the frame.
3. Turn your multimeter on and set it to a 50 volt DC (Direct Current) scale. Keeping the multimeter’s leads separated, the multimeter should indicate a reading of zero.
4. Place the multimeter’s leads onto the battery’s terminals. Touch the multimeter’s black negative (-) lead to the battery’s negative (-) terminal first, followed by the red positive (+) lead to the battery’s positive (+) terminal.
5. Observe the multimeter’s voltage reading. A well-charged battery will have a voltage of 12.1 to 12.5 volts. If the voltage is lower than 12.1 volts, connect the battery to a charger. Retest the voltage following a full charging session. Replace the battery if the voltage does not maintain a charge greater than 12.1 volts.
6. Reinstall the motorcycle’s cover or seat.