Couldn't find a specific answer to this on the search - anyone out there have an Optima red top battery they have put in the Mini S? Seems it is not a problem to have it in the trunk box unvented, but it would ease my mind a bit to hear this from others. The Optima website doesn't list a fitment for the Mini (altho it does fit, I've tried) and under FAQ about "gassing" it hedges its bets with a response ala "normally none". This an OK installation in readers experience? Thanks!!

 

I know it's been done before in MINIs by fellow NAM members. I am a big fan of the Optima batteries, myself... and I wouldn't put anything else in my vehicles... once the factory battery is worn out.

In my case, my MINI still has the factory battery... but an Optima will definitely be replacing it when the time comes.

 

The 34R is a perfect fit and it's capacity is higher than OEM.

<https://www.northamericanmotoring.com/gallery/data/500/medium/OptimaInstall.jpg>

And there is no venting required with the Optima. I left the vent in the battery well just in case but it is not connected to the battery any more.

Rich

 

Ive owned several of them but i have noticed when they fail its usualy without warning and they are dead as a doornail when they do it.

 

I have had these in both of our cars and make it a habit to return them to
Costco 2 years after purchase for new ones for no charge. I don't think
Costco carries the smaller models that fit the Mini.

 

Be advised, the 34R Red Top Optima will fit and work in the R53 only, not the N/A R50 Coopers. Dammed, stupid underhood box.

 

Okay, so I bought a 34, but not the R (terminals are not reversed)... so but I noticed that the secondary connection on the positive terminal is not giving you any issues (in the image). Mine is at nearly a right angle (so it fits with the stock battery, but not the optima). Did you bend that secondary connection or is mine different?

 

BTW, if you use the stock hold-down on the battery in an R53, you will need a piece of wood about 3/4" wide, 1/2" thick, and a few inches long to shim it down to fit the red-top, or else something 1/2" or so thick underneath the battery. The Optima 34R is about 3/8-1/2" shorter than the OEM.

I just wrapped a loose knot in the vent hose to keep it out of the way, but left it in place.

BTW, it's six pounds lighter than the OEM battery, so it is a definite go-faster.
6^)

 

I'm all for the weight savings, and shims were going to be my next question.

I can tell you don't want to shim from the bottom here. The battery housing is shorter than OEM, but the terminals make the right total height. You want to make contact with the bracket without raising the terminals.

What about the sides, did you shim the sides at all?

 

I was going to replace my battery with an Optima as soon as the factory battery failed. 6 years later, I'm still waiting for it to fail. Starting to wonder whether the OEM battery isn't a better choice afterall.

 

Tossing out your passenger and going on a diet is far more cost effective. You might also consider clearing out the empty beer bottles, but that's strictly optional.

 

Focus guys, focus... should i shim up the sides or let it moe as it will?

 

Shim baby shim.

 

No need to shim the sides, as the hold-down works fine, and the battery does not have flat sides to shim to anyway. The OEM and the Optima outside profile are nearly identical, so the fit is the same, and the OEM does not touch the sides of the hole anyway.

Nevertheless, I "shimmed" mine with some carpet scraps, which cut the exhaust noise noticeably.

 

I just "shimmed" mine with one of the plastic blocks it came with. It fit neatly between the posts and under the bracket. With out that the bracket will only touch the battery at the bottom rear (rear of the car).

As to shimming the battery with carpet scraps, are you afraid of heat or anything to that effect?

 

If it got hot enough in there to harm carpeting, the battery would have been toast long ago.

 

Yeah, I'm not worried about your carpet scraps so much, but your battery might be a concern.

Are you worried that the carpet will provide insulation for the battery to maintain any heat generated by charging or discharging and help facilitate it's demise?

 

No. The battery box hangs out in the open air, for pete's sake, and it's already "insulated" on one side by the styrofoam holder for the "tool kit". The MC even puts the battery right above the engine...

 

As do most cars... what was I thinking?

So is it a significant noise reduction?

 

I probably noticed the noise reduction more than most, because I have done quite a bit to stifle noise in my car, using Dynamat, lots of carpet scraps, etc.

Not a biggie, just one more place where some noise gets in, and as long as you're looking in there, why not?