I started noticing my cooper having issues with simply locking the car with the fob, I would have to try a couple of times. Next, I noticed a bit of a slow engine start, then a couple of nights ago, it simply didn't start, all I heard was clicking and all the dash information, such as radio, milage, and the headlights would quickly flash, then everything would go off as I tried to start the engine. I had to get a jump for a few minutes and I was able to start the engine. The next day, the same thing happened. Now, I should mention the battery is 9 years old. I'm hoping it is a dead battery at this point and not something more serious as the alternator or starter. I checked and the negative doesn't seem to have an IBS by the way. Any thoughts and/or input will be greatly appreciated.
Thanks all in advance.

 

Few weeks a go, I have similar symptoms, mine also last about 10 years, I replaced the battery with H5 Costco brand, work well.. check the cable connection to the battery , if there is not box at the end just the terminal , the battery does not require registration. if the cable has the box at the end , you need to register the battery, Bimmer link App can be used for it.

 

Got an AGM battery today. The old one was tested and confirmed as no longer usable. After the installation, the only information lost was the clock, calendar and miles ran on the gas tank since last filled. Everything else works fine, such as lights, radio stations, etc. There wasn't an IBS, so it was quite simple to change the battery.

 

AGM Batteries are (imho) well worth their money. The one fitted in my Mini is now over 11 years old with no issues whatsoever (despite the car being moved on average once, at most twice a month).

While they are quite less susceptible to wear when not fully charged, AGM batteries are not completely immune against it. And since your car comes without IBS, it may well be the case that it is charging the battery using the optimal voltage for non-AGM batteries (which is max 14.4V). If so, the AGM battery will never be fully charged since they require 14.8V.

I don't know if a Mini without IBS can be programmed to use an AGM-optimised charging cycle. However, if you have an external charger which is AGM compatible, I'd recommend using it every once in a while to top up the new battery, especially prior to letting the car sit for prolonged periods of time.

 

I found out the hard way that you have to tell your mini that your putting in a new battery. Newer euro cars, and many domestic ones require you to tell your car you have a new battery. You can do this by going by the Mini dealership or using an Android app and an OBD dongle. There are a ton of apps you can use to reprogram things on the ECU. The problem with dropping a new battery in your Mini is that it will charge it at a lower rate thinking it is an old battery. I killed 3 batteries over the last 2 years. Luckily, the batteries I bought had a warranty.