2005 MINI S with approximately 2 year old Optima battery

OK, here is the history......

3/12 - car won't start.....bring battery in for slow re-charge. This appears to work for a day or so. I bring battery back in for re-charge and again it works for a day or so. Bring battery back in for 3rd time and no further issues. Autozone checks battery and alternator...no known issues.

4/12 - while idling, gages go wild and "flutter", rpm's go down almost causing car to stall. Clock goes back to "-:--". A few days later this happens again, but causes the car to stall.

5/12 - it appears only to happen after running the car with AC on.
5/12 - after getting to work, I turn the car off and remove the keys....gages act up again. Also, car loses power as windows do not roll down and trunk won't release.

6/12 - gages act up while pulling away from red light and power steering goes out temporarily.
6/12 - bring car to local shop....cannot find any issues.

7/12 - did not drive car much the week of 7/2. Car did not start on 7/9(car had power as interior lights came on and could hear the clicking). Car did not start on 7/10(car no longer had power). Brought battery back to Autozone.

I am the original owner and there have been no issues in 7 years(only replaced oil, brakes and tires).

I replaced the original battery about 3 years ago and replaced with an Optima. After about a year, the car would not start and I ended up replacing with another Optima battery(under Optima warranty). I have confirmed that the battery ground is good.

Any help would be appreciated.

 

I do 99.9% of work on my vehicles, these electrical problems are pain to diagnose without having the vehicle acting up in front of you. Also, the person describes the problem in words from his point of view of what he/she thinks is the problem which skews the potential differential diagnosis of the problem for the car.

0.1% of the time that I take my vehicle in for service is when I have electrical problem.

Make sure the cables are tight on the battery and where-ever they go. Clean the terminals, not just the battery end but also wherever the cable is tied down.

Optima deep cycle, if drained too low, it will create internal short and won't recharge right. Optima has gone down with their quality rather rapidly it is ridiculous. I had 2 blue top deep cycle fail on me on two different vehicles both of them internal shorts.

Intermittent electrical problem sometimes are caused by loose ground as well. Believe it or not, loose ground can do a lot of odd things.

You may also have relay that is stuck on. Check your drain off of the battery see what they are when the car is in OFF position.

 

I would have the battery slow charged for 24hr. Then have a digital load tester put on it, and see what the numbers are. Also I would have them run the alternator for 10_15 minutes on the machine in the store. Never use the tester that they roll out to your car, all too often they don,t give you a legit answer. Sadly that means you have to remove the alternator from the car.

Every so often we got an alternator that couldn't provide enough charge to the battery, and the battery would slowly discharge while driving, and as someone else said, if something like a relay is stuck, it'll draw power. Lastly, my camaro's factory security system draws too much power from our car if it sirs for a few days, and is quite a common problem with our car, might want to check into that. Just my two cents

 

Btw, are you using a blue deep cycle, or a yellow one? ( blue is for marine, they don't last as long as yellows) Personally unless running alot of electrical things like a stereo system, I usually sway my customers away from them, since It's not necessary. And if you do have a large stereo system, or any aftermaket system for that matter, might want to look into that, it may be draining more power then the alternator can produce.

 

I saw that answer coming. LOL

If you know their spec (D34M and D34), the only difference between and the is the top post versus the side accessory posts. The rest is IDENTICAL. I am wrong. One more difference, one is marketed as MARINE battery and the other as automotive battery.

One other thing many don't know about the Optima batteries is the bottom of the battery is also color coded. Light gray is the deep cycle version and the black/dark gray is the starting battery.

This I KNOW personally because I go to 4x4 truck shows and one year I asked the Optima representatives about their batteries.

I and many other 4x4 owners who run 8000lbs+ capacity winches and some even 12000lbs winches run these deep cycle BLUE top light gray bottom battery. Winches draw A LOT of amps. The Optima I used to swear by but past 2 years, they have not been performing well for me.

 

Going back to the topic.

How often do you start the engine?

How long do you drive between starts?

Have you tried any other batteries?

How old is the Mini?

FYI, when AC clutch is engaged, battery is working along with the engine to engage the clutch and to turn the compressor. Substantial voltage drop/load is present at the AC clutch.

 

It is a Red Top. I purchased the Optima because I work at Johnson Controls(they manufacture the battery) and I receive a good discount.

I use the MINI to travel to work and back....about 5 miles each way.

I am beginning to believe that I am not driving the car enough.

I purchased a Battery Tender last week and have used it each night....since then, I have not had any issues.

Thanks for the replies.

 

Alternator can only do much as someone already mentioned.

However, you shouldn't need battery tender if you are driving every other day or even once a week for a few miles.

 

Five miles each way daily should be enough to keep a healthy regular battery charged, but I don't know about Optimas. The exception might be if you spend a lot of time idling at traffic lights during your commute. A lot of idling time with enough electronics going could draw down a battery more than the time at higher rpms charges it.

Having to connect a battery tender every night doesn't sound like the best solution.

 

Get a Scangauge or the like and see what the voltage is doing. This is a really good way to check things yourself while the car is running. It should be at about 14v once the system turns on after starting the car. By the way, our 2 MINIs get driven only 1 to 2 miles a lot of times and then will sit in the garage for 3 or 4 days. No battery problems. So your driving 5 or so miles everyday should be fine if everything is working right.

 

Now my PS is going out intermittently.....any ideas?

 

The PS going out intermittently COULD be a bad PS fan. If the fan is bad, the PS pump may overheat and shut itself off - when it's not overheated, it should work again.

Also, on battery drain, I heard that some circuits in MINIs stay "on" for 30 mins after you shut the car off... or the last interaction with the car: if you open the door, the 30 mins resets. If you're going to diagnose car-off battery drain, open the hood and windows and wait 30 min first.