Should I replace my battery? I assume its original. I bought the car about 1.5 years ago and its a 2003 MCS. I bought a replacement at autozone and when I went to install it I saw that the Mini battery had an indicator on it and the indicator was in the green meaning its fully charged.

I just assumed that since winter is coming up and the battery should be 4 years old now that it would be a good time to replace.

Should I wait?

 

Judging by the life I got out of my battery and the myriad posts from others who have had theirs die in three years or less, I feel that anyone running for more than three years on their OEM battery is running on borrowed time. I replaced mine with an Optima yellow top deep cycle battery with great results, others have used Optimas or other replacement batteries and have been satisfied. As most of us enter into cold winter months ahead, there will be increased demands being put onto our batteries, and those with marginal ones risk coming out to a car that wont start.

Four years on yours? I think you had a good run.

 

Many major auto parts stores can test your battery while you wait to see if the battery and charging systems are working correctly, often in less time than it takes to go to a garage and have a mechanic do it. Most of them will do it for free. I have a local NAPA store near me and I have had it done in other cars besides my MINI.

Just because a battery is old doesnt mean it will or will not fail. You can always replace your battery but if it were me, I would have it tested first, then only replace it if it wasnt up to par. I have plenty of other people and things who would like my money.

Let us know what you decide.

 

IMO, it depends on your situation. If the MINI is your only vehicle and/or you're frequently in places where you NEED (not want) your car to start, replacing at 4+ years is a reasonable maintenance decision. Sure, you could be 'leaving money on the table', but given the high tech/power centric vehicles we have today, the battery is more important than it used to be. In the old days, if the battery died, you bump start the car and move on, parking on a slope if you can't afford a new battery. The MINI uses a CPU to control the functions of your car. If it doesn't get clean power, strange things can (and have been reported) to happen.
Given that you can get a new battery for not much more than a tank of gas these days, it could be good insurance.
That said, I've got an '04 on the OEM battery and it's doing fine. I also have other vehicles, a trickle charger, and I live in a warm climate and don't drive out into the boonies much.
FWIW, there have been reports here where a battery had died, even though the indicator was green. IIRC, the indicator shows the condition of a given cell - if another cell 'dies', as in a plate dislodging.

 

My battery died suddenly a few months ago (original battery, '05 under 30K miles) and was eventually replaced under warranty.

It was a huge PITA to jump start it. when the truck came out to jump it, I had already tried to recharge it for over an hour. the guy tried to use one of those power boxes to jump it, nothing. then he hooked up the truck to the battery, nothing. Finally, he hooked up both the truck and the box and got it to start. it ran long enough for me to get to the dealer.

Once that battery goes, it's gone. Good luck trying to jump it. If you have the cash to replace it, replace it.

 

im on my stock battery and charging it every 10 days in the winter
while it hibernates.

seems like it's holding the charge quite well.

 

Tested my battery today (actually on 8/22/07 which is where this post was copied from
https://www.northamericanmotoring.co...ry#post1705722 ) 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.

 

I agree with Eric above, it depends on your situation.

I have a 4 year old battery and will not be replacing because if it dies I will simply buy an new one. Right now it is doing fine.

When I purchased my car 2 years ago the prior owner did not drive it much and the battery was iffy. After having it as a daily driver for a month the battery started performing fine.

I can't see myself someplace where having a cell phone will not get me home.

 

I replaced the battery in Artoo (2003 S) this fall prophylactically because four years is good for a battery and I went for the Optima RedTop with better cranking specs.

I did not want to have to buy a battery in haste.

Rich

 

Just searched for 'Optima battery' because when I was taking sunset pictures with the running lights on, it didn't want to start. This morning (22 degrees) the red battery light showed up, so I guess that's a hint?