Motorcycle Battery Maintenance

Motorcycle batteries don't require much maintenance but what little service battery does need is easy to perform. From the December 2003 issue of Motorcycle Cruiser. By Mark Zimmerman.

By and large, modern motorcycle batteries are paragons of reliability, particularly when compared with those we had that not too long before them. That being said, they do require some minimal, periodic maintenance.

As a rule of thumb, most motorcycle manufacturers recommend a routine battery inspection and service at roughly 2500-mile intervals, while most battery manufacturers recommend taking a look at least once a month, whether the battery is being used or not. How involved you want to get is up to you. For some of us, an inspection may mean that if the charge light doesn't come on and the bike starts on the button, then the battery must be fine. Others prefer to be a bit more proactive to avoid the hassle and cost of routine battery replacement.

Start by making sure the battery top is clean and dry. Batteries can discharge across the crud that collects on top of the case. You can wipe the case clean with a soft rag and any type of grease-cutting soap, or do as I do and just spritz it with Simple Green and give 'er a good rinse with the hose. Make certain the battery caps are tight to prevent the soap from entering the battery cells.

Inspect the battery terminals, the connecting hardware and the cables. They should be tight, clean and free of corrosion. The terminals and cable ends can be cleaned with a wire brush or sandpaper.

Inspect the battery case for any signs of physical damage, such as cracks or abraded areas. Take a look at the battery top. If it appears to be raised or warped, there's a good chance the battery was either overcharged or overheated.

The electrolyte level should be checked and adjusted as necessary. If it's low, add only distilled water, never acid, to bring it to the full mark.

Before reinstalling the battery, check the vent tube. Make certain it's not kinked, pinched or in any way obstructed. Make sure the tube is routed away from the drive chain and that it terminates below the swingarm. Don't worry about any small vertical cuts in the tube; the manufacturer put them there as a safety vent in case the tube became plugged. If the vent tube seems a bit short, and you're worried that vented acid may damage your bike's finish, you can extend the tube by slipping a length of fuel line over it.

For the finishing touch, give the battery terminal connections a light coat of dielectric grease or petroleum jelly to protect them from oxidation.

Finally, batteries are a lot like people and motorcycles; a bit of exercise is good for them. When batteries are left to sit, they're disposed to go flat. If you tend to admire your bike more than you use it, a pulse charger should be used to keep the battery up to snuff between rides.

For more articles on how to maintain and modify your motorcycle, see the Tech section of

These tools and supplies are what you need to keep your battery up to snuff. The nylon bristle brush is perfect for scrubbing the battery case. Use the steel brush to clean the terminals. A battery bottle (or a empty contact-lens-solution bottle) makes it much easier to fill the cells. Lastly, dielectric grease should be used to protect the terminals.
How embarrassing! This low-on-water battery came out of my own bike!