Yuasa - Battery Maintenance Free AGMLiving up to its name, the Yuasa Maintenance Free Battery gives worry free starting for your motorcycle and ATV through its tough and stable lead calcium design that allows for sustained performance over a long period of time regardless of inactivity. Absorbed Glass Mat (AGM) Technology is an advanced battery design used in Yuasa's Maintenance Free Batteries that eliminates water loss. So you'll never need to fill it with water check the acid level.