I'm looking for a lightweight battery kit. I know several vendors had kits years ago but battery tech has changed since then. I would like the battery to meet or exceed oem specs but weigh much less. I will be Autocrossing the car if that makes a difference.
Anyone have suggestions?

 

Even if I can't find a kit, I want to do this. What are the top choices for light weight batteries now days, that meet the Mini's CCA ect?

 

Well, it's not what you're looking for as it's much lower in CCAs and reserve than factory... but I'm running an Odyssey PC680 on top of my battery box delete (to fix a Varex muffler dead in the middle). It's 15.4 lbs instead of the 34ish lbs of the stock one, but it's also 110 CCA and 24 minutes reserve capacity. So far it didn't let me down, but I daily it pretty much all the time once it's out of storage and that roads are free of salt (about an hour of driving per day to go to and back from work).



You could look into Braille batteries. I know the 17.5 lbs one is around 475 CCA and 45 minutes reserve cap. Which is probably close to factory specs.

 

You'll need to go lithium to exceed OE specs with a lightweight battery, and that's going to be prohibitively expensive for most folks putting one in a Mini. You'd also want to run a parallel dual battery setup with a lipo battery, not entirely sure why, but I know BMW had issues and that's what they do. One regular deep-cycle, one lipo.

 

I decided to get an oem spec AGM replacement @39 lbs. Until I can keep the Mini in the Garage full time it's just not worth the hassle at this time to juggle cars, to put it on a battery tender on a regular basis I seriously considered a 21 lb. Deka AGM that cost $109 that I figured was the best compromise but really would like the 17 lb Braille or much better price wise 17 lb Deka equilavent at apx $85 Of course, even better would be one of the 4 lb or so Lithium batteries at about $ 600.