A cheap alternative to using a light weight battery, is swapping from a regular full sized battery (like the one I have pictured below) to a OEM Honda Fit battery. These batteries are pretty popular for people doing engine swaps who are looking to clean up space in the engine bay, or simply shave some weight for the track. If you are using a B or K series motor it is more then enough powerful as long as your not running some crazy stereo setup, but that would kind of kill the point of saving weight anyway.
New OEM Honda-Fit Battery (Part No: 31500-SNC-00100M) – I ended up grabbing one from a local dealership for $140 and a $16 core fee that was returned when I gave my old battery. You can see I also swapped out the old OEM battery bracket for a cheap $10 one off amazon that looks way better and won’t rust. Another benefit is that if your running a aftermarket harness like me that goes through the OEM AC plug port, the battery can be mounted farther away from it giving you better clearance.
Both batteries next to each other, you can see the Fit battery is much shorter than the normal style battery
Now lets get down to the weight savings, with the regular sized battery it came in at 28.2lbs
The OEM Honda Fit battery comes in at 21.9lbs, resulting in 6.3lb savings, which is approximately 22.47%. lighter, not bad! A nice alternative compared to expensive aftermarket lithium models, for a budget racer it’s a nice option.