Mine has had 2 replaced by the dealership.
This seemed odd for a car with only 6200 miles on it when I bought it however they said the car had sat a lot since the owner of the dealership only drove it.

If I were replacing I would probably go the Optima route. They make a quality product and since the battery is in the boot I prefer to get a cell type batter that is complelty sealed.

 

That is why I stuck with the BMW battery. Works with the vent to let out any gasses. I don't expect Diehard to do that. Looked at Optima site....They have no matches for the MINI. What has everyone been using?

 

in 150 miles, Zane will roll 100k . June build 2002 MCS . Stock battery, Northeast Mass. winters and all. Some questions for all who have replaced batteries, does all your dealer programed options (daytime running lights, one touch unlock all doors, etc.) go away and have to be re programmed?Which is better ultima red top or yellow? Jock

 

My MC turned 5 years old Saturday, still on the orignal battery.

 

Never changed my battery, but several times have disconnected it for a weekend while installing mods. The programmed options are not affected. The only things I noticed that get reset are the clock, trip odometer, and on-board computer (e.g. avg speed, mpg).

 

34R fits without issues. 35 also fits but is a little taller than the stocker.

 

still on original battery. going onto my 5th year.

the trick is to keep a good charge at all times. if the car is not
driven much like mine, make sure you charge it every 10-12days
unless you unplug the battery.

 

The Optima Red Top 35 looks like a better fit than 34R because of the location of the terminals. The terminals on the OEM battery are 1.75" up and 1.00" in, while those on the 35 are 2.00" up and 0.75" in and the 34R are 2.25" up and 2.25" in. Fitting the Optima 34R requires straightening the right-angle connector on the end of the B+ wire from the fuse module.

Optima Red Top 35 (couresty of kapps):


Specs: L x W x H = 93.313" x 6.813" x 7.625" || Weight = 33.1 lb

Optima Red Top 34R (courtesy of Rich.Wolfson):


Specs: L x W x H = 10" x 6.875" x 7.875" || Weight = 37.9 lb

The Optima Red Top 34R has move cranking power than the 35 (800 vs 720 CCA) but the OEM battery only has 480 CCA.

 

117,000 Vermont miles and the original battery is still doing the trick.

 

There's one in every bunch. I hope you feel special now.

Thanks for the Optima input guys. The 35 might be my next ( after 117,000 more miles, of course. ) battery. Oh just general info...I did get 81,000 miles on this first battery.

 

MINIAC, one thing I have to note... I'm not sure if this is the same for the 34R but on my 35, the terminals are taller than stock while the actual body is shorter. This means the connectors are touching the insulation below the boot floor. Mine began eating away at the insulation as the battery slid around (remember I said the body is shorter meaning the metal hold-down piece doesn't do anything). To remedy this, I got a piece of high density foam and cut it to fit between the hold-down and the battery to keep it from moving. It seems to have done the trick.

 

According to the specs on the Optima site, the terminal tops of the 34R are slightly taller than the 35. Rich indicated via PM that the "feet" on the hold-down bracket held the 34R tightly in place, but didn't say anything about indentations in the insulation.

I believe the OEM battery is 7.5" to the top of the terminals. On my OEM battery there is a slight gap between the battery top and the hold-down bracket.

 

The top of the bracket is not what holds the battery in place (OEM or aftermarket), rather the lowest part of the hold-down bracket grips a flange on the base of the battery to keep it in place. There is a matching, fixed 'gripper' welded into the battery box towards the front of the car. Tightening the long bolt squeezes down on the clamp and forces the battery forward, eventually binding it in place. The high part of the hold down bracket is merely there to support the carpeted floor piece above. The replacement battery needs to have the flange for proper fit (the Optimas have it built in). I put plastic caps on the fixing nuts on the terminals to keep them from digging into the insulation. All fits perfectly.

 

Tested my battery today to see what kind of shape it's in after 4 1/2 years.

Copied this from http://www.repairfaq.org/ELE/F_Car_Battery.html

6. HOW DO I TEST A BATTERY?


The are four simple steps to test a car battery--inspection, remove surface charge, state-of-charge test and load test. To test a battery (or to troubleshoot charging or electrical systems), you will need a digital voltmeter with .5% or better accuracy. A digital voltmeter can be purchased at an electronics store and will cost between $20 and $200 U.S. If you have a non-sealed battery, you will need a temperature compensating hydrometer which can be purchased at an auto parts store for approximately $5 U.S.
6.1) INSPECTION


Visually inspect for obvious problems, e.g., loose alternator belt, low electrolyte, corroded cable or terminal clamps, loose hold-down clamps or cable terminals, or a damaged case.
6.2) REMOVE SURFACE CHARGE


If you have just recharged you battery or driven your car, eliminate any surface charge by one of the following methods; otherwise, go to the next step:

1. Allow the battery to sit for two to three hours,
2. Turn the headlights on high beam for five minutes and wait five minutes, or
3. With a battery load tester, apply a load at one half the battery's CCA rating for 15 seconds and wait five minutes.

6.3) STATE-OF-CHARGE TEST


Using the following table, determine the battery's state-of-charge:

Battery Voltage - State-of-charge - Specific Gravity
12.65+ ..............100% .................1.265+
12.45 ................75% ...................1.225
12.24 ................50% ...................1.190
12.06 ................25% ...................1.155
11.89 .................0% ...................1.120
[If the temperature of the electrolyte is below 70 degrees F (21.1 degrees C), then add .012 volts (12 millivolts) per degree below 70 degrees F to the reading.]
For non-sealed batteries, check both the specific gravity in each cell with a external hydrometer AND the battery terminal voltage with a digital voltmeter without the engine running. For sealed batteries, measuring the battery's voltage without the engine running with an accurate digital voltmeter is the only way you can determine the state-of-charge. Some batteries have a built-in hydrometer which only measures the state-of-charge in ONE of it's six cells. If the indicator is clear or light yellow, then the battery has a low electrolyte level and should be refilled before proceeding, or if sealed, the battery should be replaced.
If the state-of-charge is BELOW 75% using either the specific gravity or voltage test or the built-in hydrometer indicates "bad" (usually dark), then the battery needs to be recharged BEFORE proceeding. Replace the battery, if one or more of the following conditions occur:

1. If there is a .050 or more difference in the specific gravity reading between the highest and lowest cell, you have a weak or dead cell(s),
2. If the battery will not recharge to a 75% or more state-of-charge level or if the built-in hydrometer still does not indicate "good" (usually green, which is 65% state-of-charge or better),
3. If digital voltmeter indicates 0 volts, you have an open cell, or
4. If the digital voltmeter indicates 10.45 to 10.65 volts, you have a shorted cell. [A shorted cell is caused by plates touching, sediment build-up or "treeing" between plates.

6.4) LOAD TEST


If the battery's state-of-charge is at 75% or higher or has a "good" built-in hydrometer indication, then load test the battery by one of the following methods:

1. Turn the headlights on high beam for five minutes,
2. Disable the ignition and turn the engine over for 15 seconds with the starter motor,
3. With a battery load tester, apply a load equal to one half of the CCA rating of the battery for 15 seconds, or
4. With a battery load tester, apply a load equal to one half the OEM cranking amp specification for 15 seconds.

DURING the load test, the voltage on a good battery will NOT drop below 9.7 volts with the electrolyte at 80 degrees F (26.7 degrees C). [If the electrolyte is above 80 degrees F, add .1 volt for every 10 degrees above 80 until you reach 100 degrees. If below 80 degrees F, subtract .1 volt for every 10 degrees until 40 degrees.] After the load is removed, wait five minutes and the battery should "bounce back" to the 50% state-of-charge level or above. If the battery drops below minimum test voltage, does not bounce back, or will not start the engine, then you should replace it. If the battery passes this test, you should recharge it to restore it to peak performance.


My results
12.44 V at 70 degrees after removing surface charge = 75% state of charge.
10.60 V at the end of cranking for 15 seconds with spark the plug wires disconnected.
12.42 V 5 minutes after the above load test.

They suggest replacing a battery that has less than 75% state of charge,
so I'll probably replace it later this fall.

Mine is borderline on the state of charge test and did fine on the load test.

 

It's not totally dead, but 4 years 3 months and 69959 miles is apparently normal.

 

It will be 5 years old in July, now has 93,000 miles on it. Still snaps my 03 MC to life everytime And that after 3 winters of -40c/f temps

My wifes 05 Cabrio battery had to be replaced this past Sept.

Mark

 

Original battery in my '02 (Purchased 09/02) with 48,000+ miles. Stil fires up but I think I will replace so I don't get the dreaded click click click.

 

40,000 miles and 5.5 years on the OEM battery.

Who said they have a braille battery? What model did you get? I'm going lightweight when I need a new one.

 

March 02 Cooper S, 68,000 miles and origional battery. no problems

 

March 02 cooper with 145k on original battery... Still seems strong. If it does die I will be pop starting (gotta love a manual transmission) and driving to get a new one.

 

We had a fluke, as a cell within the battery died within 2 years, but replaced by MINI and so far no problem.

 

And it still cranked fine - I just figured it was time before it left my kid stranded somewhere.

 

'04 MC also in massachusetts .....4 years and 60,000 mi....no problems at all

1) over the years, I've had batteries die and they always gave the warning sign of slow tired sounding cranking upon cold starting...it seems the MINI battery will suddenly just die without warning....is this unusual?

2) if (when) it dies die, how bad is it for the car and for the car's electronics to pop the clutch to get the car going to get to a new battery service call?

 

When my battery died I did experience the slow cranking up issue beforehand, but it was only for a day or so and frankly I didn't fully realize the issue at the time (it was such a small difference in crank time I thought I might just be imagining it). So at least with my experience I did have a little warning.

 

thats a loaded question. how much do you drive it?