[Honda100]

I had a Nissan 240sx with a a 54 lb battery and then went 180 CA little tiny pack that I made myself. Weighed 14 lbs I think. However though, the CR on my car was 13.1:1 and the battery quite often did not have the power needed to turn the motor over, so I often had to bump the starter a few times until fuel made it into the cyilnders, which would lube them enough to get the car to start easier. However, that battery was for a track car, so I'd assume a regular car would be fine.

Also on a stupid note, for my Super Cub, I soldered a pack of NiMh double A batts (10 total) to make a 12v pack and it works just fine. I saved a massive 3 lbs of weight!