Hello this is my first post and I have tried searching to find a similar issue like mine. So I apologize if this is a repost.
I purchased my 2010 Mini Cooper Hatchback S in 2013. Since then I have had to have a brand new engine installed (due to animal that hit on a toll road in Texas) and a new clutch (due to a issue that I found in threads here which is why I am coming to ya'll now). Just recently I had a issue with my wipers not working I went through the threads etc and tried the quick fixes (I do have warranty and extended warranty etc on car) but took it to the dealership where I was told it is do to weather (there was water on my passenger side but it hasn't rained in San Antonio Texas this summer at all) I said fine I'll deal and check others have not had the chance and I still don't believe. I do believe it is a sealing problem as to how water damaged the Control Box, whatever it is called. That has been on the back burner of things I wanted to deal with it still drove perfectly fine.
Recently about two three days ago I started to smell a egg smell when ever I would stop the car and have the A/C on..it would then get to a sour smell over time eventually going away when I started to drive. Also had slow starts with the push start. I called a mini approved shop (due to wanting to get a outside dealer view and due to previous experience with dealer and my warranty, there is always something etc) and setup to bring it in. Did not have the chance . I'm driving from work, stereo sound just stops, stop at my local corner store grab some items starts up fine. Stereo music is back on also think nothing of it. Get home unpack then have to go back out ...try to start the car nothing...I see some of the instruments try to come on...etc. Get out and try again nothing. I don't understand...little by little more and more items just are dieing. Eventually give up..neighbor comes over we try to jump it..nothing still...takes jumper cables off says they are ultra hot and believes there is power but looking at something electrical. I called MINI roadside and (that was a episode, lets just say the towing company cant tell the different between a creme mini and a blue mini in the dark) and took to the nearest dealership. THE ONLY dealership in San Antonio.
I get a call from service tech instantly says battery (has not checked) and quotes a 325$ bill. Crazy talk!! it includes some resetting crap (I now know as possible crap, due to some of the forum posts etc). I am wondering could this be something else or am I truly stuck. Again I have warranty like crazy and extended ..unfortunately battery is not included...anther crazy talk. Again any help would be appreciated...I really do love driving this car the techs etc have always been great (nice) and I know they also have a business to run....now should I run and have it taken to the non dealership..or stay and take it because it could really be the battery and that is a common go to etc

 

It is possible the egg smell is from the result of overcharging... the chemical result of electrolysis (the reaction in the battery) resulting in the over production of Hydrogen (sometimes identified by the rotten egg smell)

If that is the case, then it is possible the alternator is in an overcharge state and is cooking your battery (this could also cause the jumper cables to heat up when attempting to jump the car)

At this point you can't just say battery, you have to have the alternator checked and most importantly the ground cables.

Have the car worked on where you are comfortable with the service and work.

Best of luck...

Motor on!

 

First THANK YOU THANK YOU for the reply. I do hope you are right and it makes sense as I'm reading and going over all the symptoms and piecing them together...I really don't want to fork over 325$ for a battery when it is something entirely else that luckily would be covered. I will most definitely repost with findings because this just became interesting

 

Well dealer called back and informed it was just the battery...and when the battery dies it will sometimes give off that hydro sulf smell, tel-tale sign that it is dieing. Go figure. Either way I will bring up the alt check when I go and drop 350$ on this battery.

 

Thanks again grateful for this forum and so glad that there are people out there that take the time to give just a small piece of mind when it is needed.

 

JABowers has a good point about the alternator, be sure they check it. Since you're driving a 2010, bet it's the original battery. In which case, it's due to be replaced and bad batteries in a Mini will do all kinds of weird things..

 

Interesting, I'm on my original battery on my 07 MCS. Now we all know what to expect when our batteries take a dump, first time though I heard about the smell of rotten eggs. $350 isn't bad a price coming from a Mini dealer as I have seen $400-$600 for a replacement battery.

 

Seven years on a battery, you've beaten the odds. Once I've hit around four years on a battery, I just go ahead and replace it. I don't like being stranded. But then again, the summer heat here in Phoenix kills them fast..

 

My battery isn't showing any signs of age, I even roll my windows up and close the sunroof with the engine off.