I put a ytz-10 battery between the a-arms. Made a strap to hold the battery down, made couple brackets to hold the voltage regualtor & the cdi box. Think the stock battery has 230cca, the battery I installed is 190cca, but weights close to 10lbs less. Now oil changes are so much better, the R1 uses the same battery & the ytz-10 is in lots of quads. Didnt have any issues with starting, some buddies went with the ytz-7. But its only 130cca's.