From the J&P Cycles Blog Archive

Motorcycle batteries. We tend to take them for granted. They're reliable (most of the time), easy to maintain (if done correctly) and economical. But there are a few things you should know before you buy one and more important - after you buy it that will save a major headache down the road - literally!

When preparing to purchase a new battery, make sure you've got the right one. Over the years, Harley has utilized several different types and styles of batteries. In the old days, when the kicker was the only means to start the engine, batteries had a relatively easy life. All they had to do was power the lights and provide the juice for an occasional toot of the horn. Then things got tough for batteries. The electric starter began making demands on batteries that really taxed the conventional 12-volt lead acid battery. These days, we still have the traditional design along with the low maintenance, lead calcium battery. Many people use the sealed cell batteries, introduced on the new H-D models in the 1997 model year. In addition we also have some newcomers from the aftermarket. A couple years ago, we saw the introduction of true sealed cell batteries, maintenance free (sic) for electric start Harley-Davidson motorcycles. This "maintenance free" technology (there is always some maintenance involved) carries a price however, so be prepared to pay a little more for this type of battery.

Regardless of what type of battery purchased, take the time to set it up properly. The first time a battery is charged is the most important charge of it's life. Most batteries are "dry charged" and although they will perform adequately (for a while) without additional charging, the state of charge is normally about 45% to 50% after servicing. As soon as the battery is connected to your motorcycle's electrical system and loaded (this happens as soon as you turn the ignition switch on) the battery takes a "set." In other words, if your new battery only has a 50% charge when you install it, it will never reach a higher state of charge. Talk about operating under a handicap!

To get as much as possible out of your new battery, follow these guidelines:

  1. If you're dealing with a conventional battery (lead acid or lead calcium), fill the cells slowly. Allow the air to dissipate from the cells, this usually takes 20 to 30 minutes. Then top off the cells. Never over fill the cells!

2.  After letting the electrolyte settle and soak into the plate material, charge the battery for at least 8 hours at a rate of 1/10th the battery's amperage rating (not to be confused with cold cranking amps). I prefer a manual, fixed rate charger. You can usually purchase a good 12-volt, 2/6 amp manual charger for under $35. My favorite method is to charge the battery at 2 amps for about six or seven hours, then switch it to 6 amps for that extra push.

3.  Keep tabs on the battery temperature while it's charging. The battery case should not be warm to the touch. If the battery plate temperature exceeds 115°, the plates can warp, creating the possibility of an internal short. If it becomes warm (not likely if you keep the charge rate at 2 amps), simply disconnect the charger until it cools off.

4.  After you install the battery, make sure the vent hose (if it has one) is routed correctly. This means keeping it away from hot things, like cylinder fins, exhaust pipes, etc. Also make sure the hose doesn't become pinched or kinked. It's also important to insure the hose doesn't terminate close to parts such as drive chains or belts, wheels/tires and exhaust pipes. It should be long enough to hang at least 1"-2" below the bike's frame.

5.  Coat the battery connections with some type of protectant. I've used everything from terminal coat to wheel bearing grease. Something that works extremely well is the chain lube, particularly the non-foaming O-ring type.

6.  Match the care you give your battery to your riding habits. If you tend to take a lot of short hops (stop-and-go city riding conditions), the battery tends to become discharged. Each time the engine is started, it takes 10 to 15 minutes of operation at highway speeds to restore the battery's charge. This rarely occurs if most of your riding is in the city. If this profile fits you, invest in a good trickle charger to help maintain the battery whenever you're not riding. A little trick many people use is to connect a regular charger to a programmable timer (the kind you can buy for $5 at the local K-Mart). Set the timer to charge the battery for an hour or so every day and you'll add years to your battery life.

The old saying goes "out of sight, out of mind." As part of your regular weekly maintenance ritual, make it a point to keep an eye on your battery. Make sure the connections are clean and the electrolyte is at the upper level. Don't fill the cells up to the top! This can ruin a battery by allowing one bad or weak cell to contaminate the others. Use only distilled water for topping off the low cells.

Some people prefer to remove the battery from the bike for long periods of storage. This really doesn't matter, one way or the other. Whichever way you prefer, make sure the battery is regularly maintained. By this, I mean never let the battery go for more than a two-week period without charging it. Even on a wooden bench, with clean terminals, the best batteries in the world will become discharged. When this happens, it's all over for the battery (particularly with today's low maintenance lead-calcium batteries). Well, that about wraps it up for now. Hope you got a charge out of our look at batteries!