these are the specs in our reference system. I'm sure there's a very small +/- margin, but it should be really close: DRZ400 battery "YT7B-BS": L- 5.9" W- 2.56" H- 3.66" 5 lbs CRF450X battery "YTZ7S" L- 4.44" W- 2.75" H- 4.13 4.7 lbs Thanks for posting that cornelieaz. I put the DRZ battery in my airbox. The height and width are smaller then the CRFX battery, which is good for wedging it into the airbox. The length is larger, but as long as it fits between the frame members (which it does) then that dimension doesn't really matter. The DRZ battery does weigh more, but it's really insignificant.