Ask the Editors: Maintaining a Maintenance Free Battery
You’re absolutely right, a majority of the batteries nestled within our ATVs are the same lead-acid boxes that have been firing up automobiles and lawnmowers for decades (there are some exceptions as lithium ion and polymer are starting to come on the scene: basically larger versions of a cell phone/ laptop or RC car battery).
What is meant by maintenance free has all to do with the fluid inside the battery. Years ago the metallic plates inside of the battery were literally suspended in a pool of acid. This acid would evaporate or leak over time and it was literally become the consumer’s responsibility to make sure the cells were topped off for the battery to work.
Maintenance free batteries are sealed from the factory and the plates inside surrounded by something called AGM or Absorbent Glass Mat. There is still sulfuric acid inside but instead of being a chamber of liquid, it’s absorbed by a very fine fiberglass layer, making the battery spill-proof.
ATVs are perfect for this technology because being sealed, AGM reduces the risk of acid spilling in a crash, lowers the weight without a hit on performance, works well in cold temps and allows battery installation at odd angles.
In the long run, we’ll probably witness the whole lead acid battery become phased out by some of the much smaller, lighter and quicker-charging technologies mention above but for now, maintenance free simply means no futzing with liquid-filled open cells.
