Bike Battery Care and Feeding | Motorcycle Cruiser

Bike Battery Care and Feeding

A Few Tips On Maintaining Your Ride's Power Source

With a good chunk of riders finally rolling their bikes out of the garage after a long winter, there's no better time than now to go over the finer points of your bike battery's maintenance regimen. We looked over a few recent tips from Harley-Davidson service experts, and came up with these takeaways.

A motorcycle battery is always working. Even when your bike is parked, the battery discharges continuously in small internal loads called “self-discharge.” Self-discharge speeds up drastically as the temperature rises – like, for instance, in a hot garage in the summer – and accessories like alarm systems will only increase the rate of discharge. If a battery is discharged too deeply, for too long, it can be permanently damaged. Then when you push the starter button, all you're left with is the sound of silence. No more Saturday ride.

Because motorcycles may often be parked for some time between rides, they're especially prone to battery damage from deep self-discharge, even during the riding season. The best way to prevent premature battery death, according to the pros at Harley-Davidson, is by keeping a parked motorcycle plugged into a maintenance-type battery charger like a Battery Tender. Instead of standard battery chargers, look for units that feature internal circuitry to charge a motorcycle battery at the proper rate and can then change modes to protect the battery from over-charging.

The good choice is the new Harley-Davidson 800mA Waterproof Battery Tender (P/N 66000004, $49.95) which features a three-step charging system that constantly monitors battery voltage to bring the battery up to full charge and switches to float mode to maintain the charge over extended periods. Its waterproof case protects the charger from damp floors and outdoor elements, and the charger is reverse-polarity protected and spark-proof, even when the leads touch. The charger is sold with a fused alligator-clip harness that’s handy for charging the battery when it’s removed from the motorcycle for long-term storage, and with a fused ring-terminal harness that can be connected directly to the battery terminals and left on the motorcycle. It’s then easy to plug the charger into the on-bike harness whenever it’s parked. (Harley-Davidson has equipped all 2014 Touring-model motorcycles with a factory-installed battery charger wiring harness).

Battery Life and Replacement The true life of a motorcycle battery is determined by many factors, but most sources agree that a well-maintained battery should deliver at least five years of service. AGM (Advanced Glass Mat) batteries can be a good choice because they're sealed and never need added electrolyte, and won’t leak even if the case is punctured because the electrolyte is absorbed in glass mats placed between the positive and negative plates. Stainless steel terminal bolts to resist corrosion are a desired feature to look for, too.

Service Tips for Battery Safety

• Always exercise caution when working with batteries. • Wear eye protection. • Keep sparks, flames and cigarettes away from batteries at all times. • Never lean on a battery when jump-starting a bike. • Never store a battery in a sealed container; always allow for proper ventilation.

For more tips, see our related article on batteries here or you can visit for Harley-related details.