I just replaced the bmw brand battery with the 34R Optima red top. It fit almost perfectly. The only modification necessary was to slightly bend the positive terminal connector to get it onto the terminal. All is good otherwise.
This is for the '04 MCS, battery in the boot!

 

WOW......I think this is the longest I have heard of an OEM battery lasting in an early car.

 

I still have the original battery in my '04 MCS. 34R Optima, eh?
Good to know. I'll need it one of these days...
Thanks

 

I have a September '03 build MCS still on the original battery at ca. 70k !

 

05 build here, still on original battery...!!

 

03 MCS 110k original battery

 

Me too!! 03 MCS 110K original battery!

 

Has anyone used the Interstate MT-47 battery? It's also higher-capacity than the stock battery (although not as high as the Optima 34R), but I can get it locally for half the price of the 34R.

It's the model that Interstate recommends on their site, and I know the terminals are in the right place, but I haven't found anyone yet that's actually used it, so I don't know if it's a 100% drop-in replacement.

 

Go look at it..you may need to order the vent kit....if there are places to connect tubes to vent the hydrogen gas that is made when a flooded cell battery is charged (like the OEM).
Spiral wound, recombinant gas, sealed battery's like the Optima are not flooded, sealed, and would only vent gas in some major type of abnormal event.
The Optima is a different group than the stock, and it is one reason it has so much power, along with the design, bit it fits.

 

I remember having the OEM battery in my car for many years past when it should have died.

Then out of nowhere, on a day when I really needed to get somewhere, it just died without any warning.

That is why I now replace my batteries just before they are ready to expire; I don't want to be surprised again even if it costs me alittle $ sooner.

I too replaced the BMW battery with the Optima !!! Its design is safer for the MCS, since the battery is located within the passenger area !

 

Me three. 03 MCS 101223 miles on the original battery. Looking at getting the Optima sooner or later

 

Is there a way to maintain the OEM battery?

 

I put a charger on my car once a year to top up the charge. Usually in the summer (and in the shade). I am still on my original battery.

In the 70's I had a Pontiac that I meticulously maintained and when I sold the car in 1985, it was still on its original 11 year old battery. Granted, 70's cars had a lot less electronics than current cars to. However, I also had a car that I did not maintain charge every year and I ended up replacing the battery every 3 to 5 years.

 

OEM batterys are kinda un-even in quality on MINI's....many 05' owners got new batterys for free under re-call of sorts in 07.....so some of you with a "orgional Battery" may have a newer one, that was an OEM one....it seems like 50% of the orgional owners got new bats before the end of the 36 months bumper warranty.........so the fact it says MINI does not mean much...
The fact the battery is in the rear on the S means it is not exposed to as many temperature variations, and it is generally in a location one would expect a long life....IF it is driven regularly for and hour or more....so the charge can be kept hi. Less frequently driven cars, and the longer cable runs, seem to have the battery's fail pretty fast from suflation, partiality a result of the batts being kept for periods of time at less than 100% charge. Some better battery charges have a special DE-sulfatation mode...it can work, but takes several days....
On a MINI that sees mostly short trips, a battery minder might be a good idea, or perhaps, like what I did, get a better battery. The Optima's have lower internal resistance, and will accept the charge faster (so they "get FULL" more quickly after a start...important due to the long cable run), and do not deteriorate as much as flooded cell batteries...they stand up to being under charged, discharged, temperture extreemes, etc....the one drawback, is they are a bit bigger....(due to it being a differnt group battery!!)
But in my book, since I use the car as a daily driver, the extra 10 pounds is not an issue!!

 

My battery just died and was looking on this thread to find a suitable replacement. It was the original battery.

2002 MCS, 65k miles.

I dont drive the MINI in the winter and have it on a battery tender in an unheated garage, so it may not have seen the full brunt of 4-season environment that others have seen.

I'm going with the Optima 34R to replace.

 

Last week I came out to my car two days in a row and my windows were down about an inch. I remembered reading here that it might indicate a battery about to die, so I decided to check it. I had never looked at it closely, but the light was not lit, and I figured that wasn't a good sign. So, called Autozone and they had a optima 34R in stock, drove up, slapped it in and i'm feeling good about the next 5 years. My car is an 06 with 42K on it.