My 2003 MCS still has the original battery and it loses charge if not used for a few days, so it's finally time to start shopping for a new battery. I originally planned on buying a lightweight battery, but because I occasionally keep the car stored for long periods of time and have an aftermarket stereo with amplifier and subwoofer, I think that will be too much to ask for from a tiny battery.

I have read several "Dead battery" threads on NAM and it seems like most advice others give is quite vague. Several users recommended getting an Odyssey or Optima battery, but when I looked on what model to get, their website doesn't have a battery listed for the MINI. Please forgive me, but I don't know enough about car batteries to know what's best for the MINI.

Also I recall reading a couple threads about people buying cheap replacement batteries and they somehow ended up leaking acid, corroding some shift link cables and costing lots of $$$$ and time to fix.

I prefer to find a replacement battery in the $70-$150 dollar range. Anyone want to throw out some ideas?

Finally, I just talked to Midwestern MINI parts and the oem battery retails for $140 and has a 2 year warranty. As of now, that seems like the easiest and safest option.

 

I believe, almost positive, the Optima 34R is a perfect fit replacement. Its a great choice if the car either sits for long periods or has some stereo work done, both you say you have. Optimas are not cheap though. I've seen the 34R for about 200 bucks, but properly maintained, it will outlast any other battery.

 

The reason you can't find a battery on the sites is because they don't have one with the same group size as the stock battery. The stock is group 47. I have a group 35 Optima and it fits without any issues. I've also read a 34R fits. Check Sears, they had one of the best prices I found.

The Odyssey is more of a lightweight battery but it's also very good. They are also deep cycle unlike the Red Top's. Only Optima Yellow Tops are deep cycle.

 

Hey you all, i'm saving up and hoping the finances are going to work out this year but... i'm thinking of getting an 07 MCS and I was wondering if it would be possible to switch out the stock battery with an Optima...

I've got a Red35 in my Ford Focus right now, but it looks way too big for the tiny space in the mini.

Please let me know!!!

 

I'm not sure what group size they use in the '07's. If it's the same group 47 as the 1st generation, you should be good to go.

Oh, and welcome to NAM

 

Personally I wouldn't spend money on an OEM battery - they replaced ours under warranty and in less then a year the new one is fading already. The batteries were also similarly bad in the BMWs we have owned, it is very strange.

 

I currently have an Optima Yellow Top group 34 in mine. Fits without issues. Any replacement you select should either be of the AGM (absorbed glass mat, like the Optima or Odyssey) style or an externally vented wet cell like the OEM battery. This is to prevent gas buildup inside the car (AGM batteries by design do not vent nearly as much during normal operation) and also to prevent any electrolyte spillage in the battery box. Unlike many cars, the MCS battery tray is welded into the trunk floor and is made of thin sheetmetal. It's an expensive proposition to replace the battery box, and it would not take much acid leakage to eat it up.

The Optima 34R has the proper, 'reversed' terminals. The Yellow Top deep cycle battery is not available in the reversed configuration, but the battery itself can be turned around and the battery leads attached without difficulty. The fused lead has to be bent up slightly for clearance.

 

I love my new 7-year Interstate battery. The tow truck operator said that he doesn't see them dead in cars he tows.

 

What's the model number?

 

Not sure about the number but make sure you get the BMW vent tube like this one

 

OPTIMA R34 is the perfect fit. I have used the Optima Red Top in my last 2 cars. Fantastic. If you have it installed be sure and have the installer give you the battery vent system when the install the Optima. The Optima does not require venting. My wife had an Interstate (Makes the Optima) battery installed in her BMW and they removed the vent system. 8 months later, we had a service at BMW and they wanted $230.00 to replace the vent system. You gotta be kidding!

 

I've had Optimas in other cars and never had a problem. I get them here... http://www.remybattery.com/ProductIn...uctid=34R-1050 usually the best prices I can find, and always good service.
As far as what to get, just measure the battery, look to see that the terminals will fit, and then get the max cranking amps you can find. With the MCS you want to be careful with the venting. Optima's require very little venting if any. Last one I had was for a Miata and they love them over at Miata.net.

 

Well, my roommate has a MCS 07 and i've been poking around under the hood... the problem is that the original battery is REALLY tiny, once he gets back i'll be able to get dimensions, but I know that the battery compartment is way different from older model minis.

The reason for the optima is because i'm looking to install a modest sound system. That, once again, is going to be hard to do in the mini.

If anyone has an 07 mini and has installed an Optima, PLEASE post your results!!

 

What results would there be? ""Installed and it started?
Measure it up, then go to the Optima site and see if one looks close. If you're going with a sound system you'll probably want a yellow top. Otherwise the red top is a great starting battery. I used to store my Miata for 5 months with no charger and just hop in and start it in the spring. Amazing batteries.

 

Well, I own a red top now and it works wonders with my sound system anyway :D but see, I measured out the stock battery and it's 8"x6.5"x7.5" with the terminals in a [ + - ]orientation.

The only problem is that I don't know if it's possible to get it in there or not. There's all this plastic stuff around the battery.

 

I definitely want a yellow top Optima for my 05 S Convertible. I notice the yellow top D35 does have the terminals in the proper location. It is 1 inch shorter in length (9 instead of 10), 0.1 inch narrower, and the same height. Will this affect fittment from your experience?

The D35 also has only 48 AH vs 55. My Bently Manual clearly states not to install a replacement battery with fewer than 55 AH. I would think, however, that the battery life will not be affected as the yellow top will better handle discharge (which would be slightly deeper given the same conditions). It would affect the period of time you can leave your car unstarted but as my car is a daily driver I don't anticipate any problems there.

Any comments. I'm thinking you may have considered this battery but decided the difficulty of the non-reversed terminals were less of an issue than the small size of the D35.

 

I love my 7-year interstate battery in my 03 MCS. Good luck!

 

I can't imagine "loving" any battery. To me, a battery is just a source of electrons with a warranty. Eventually they all have to be replaced and hopefully this happens under warranty.

I use a red top Optima in my Land Rover Defender solely because the battery box is located directly under the driver's seat and I'd prefer to keep my butt from being burned by acid.

In my MCS, I have a gold Duralast battery from Autozone. Their replacement battery for the MCS comes with the correct vent tube. Make sure it is included when you buy it. It is a lot cheaper than OEM or Optima and has a good warranty.

 

Well, for situations such as sound systems, an Optima really helps to make your car last a lot longer. My old Duralast was usually dead in about 30 mins of playing music with the car off, but with the Optima the car can last anywhere between 2 and 3 hours and still start my car!!

 

Alright you guys, just for reference... I switched out my battery and it fits great!! It's a direct swap!!

 

just be glad U dont own one of the new Pontiac GTOs from 2006 on-- my friend is still waiting for a battery for his from the dealer (over a month now) because the GTO is a (Australian) Holden, and since Holdens are mostly built RHD, the +/- battery posts are flipped around from what they should be for a LHD car. Very problematic.

 

The Optima's are great as they aren't a lead acid battery so no risk of leaking. The Optima battery also does not emit "dangerous" vapors like lead acid batteries. You are supposed to vent any lead acid batter installed in a passenger compartment to combat that.

With batteries, it is usually best to buy local so you can take advantage of the warranty by walking into any local shop. I prefer Sears as they are everywhere.

 

I just bought a Interstate 34r Should I discard the vent tube from my oe battery?????

 

Is that an Optima sold by Interstate? If it is a gel cell then it does not need the vent but I left it in the battery compartment when I put in my Optima just in case some day.....

If it is a regular lead/acid battery then it needs the vent as in its regular course of business it gives off hydrogen.

Rich

 

^^
Its just a regular Interstate I made a bunch of calls and could not find an Optima in my area.My wife wants to drive her new toy and is not happy that the battery is dead already.Would it hurt to put the Interstate in until I can find an Optima??