April 26 2012 by Jason Fogelson
It's spring, so you might be thinking about getting a new battery for your motorcycle. If you didn't take the time to put your battery on a smart charger for the winter, you're definitely going to have to do more than just think about it. Motorcycle batteries are much smaller than car batteries, which is one of the factors that contribute to their shorter lifespan (and warranties). I've had good luck with my batteries over the years, mostly because I'm kind of obsessive about keeping them hooked up to a Battery Tender smart charger in between rides, even during good weather. My most recent battery lasted almost ten years, thanks to careful maintenance, and the fact that I live in a very moderate climate.
If it's been a while since you bought a new battery, the variety of battery styles might be a little overwhelming. It doesn't need to be.
There are two basic types of motorcycle batteries: Conventional (wet) and maintenance-free.
Conventional batteries are the old-fashioned wet batteries that need to be kept full of distilled water and checked periodically for electrolytes. They are subject to damage from vibration and heat. These batteries must be mounted upright, or they will leak and fail, and the battery fluid is acidic and corrosive to paint. The main advantage of a conventional battery is price -- they tend to be the least expensive motorcycle batteries available. Some older bikes require conventional batteries -- check your owner's manual and service manual to be sure.
Maintenance-free batteries come in several varieties. Harley-Davidson equips all of its current bikes with AGM (Absorbed Glass Mat) maintenance-free batteries, which are designed to be heat and vibration resistant. Their cases are completely sealed, valve regulated and equipped with stainless steel terminal bolts that won't rust or corrode. There are many different sizes of AGM batteries, even within the Harley-Davidson system, so be sure to get the right one for your bike.
The latest development in maintenance-free batteries is the gel battery. The difference is that instead of a wet medium within the battery, like what's inside the conventional and AGM batteries, the gel battery uses -- you guessed it -- gel. The advantage of a gel battery is that it will not leak, even if the case cracks. A gel battery can provide even greater resistance to heat and vibration, and because of the nature of the battery, a smaller gel battery can provide the equivalent cranking power of a larger conventional or AGM battery. Gel batteries can also be mounted at an angle, or even on their sides, which makes them popular with custom builders, because it makes battery placement and installation more flexible. The downside of gel batteries is price, and the fact that some motorcycle charging systems may need to be adjusted to perform optimally with a gel battery.
If your motorcycle battery is more than three years old, or has fails to hold a charge, have it tested before the riding season starts. Make sure that there's nothing wrong with your bike's charging system before you invest in a new battery.
If you do need a new battery, there are a few things to pay attention to beyond battery type. Make sure that your battery matches with your bike's cold-cranking amp (CCA) requirement. This is a measurement of the battery's power at zero degrees Fahrenheit, which is the situation where battery power is at its lowest.
Make sure that your new battery is fresh. Batteries can sit around a motorcycle shop or retailer for quite a while before they are sold, especially in odd sizes. Every new battery should have a shipping date marked on it. Find one that is less than six months old to install in your bike.
Finally, be sure to dispose of your old battery properly. Don't just toss it in the trash -- it contains lead and other toxic materials that need to be handled appropriately. Most battery shops will accept used batteries for recycling, usually for free or for a small fee.
Keep it charged and keep that bike on the road, not in the shop