Hello, another minor issue for me. On my 2012 R60, most days when I get in the car and start it up it gives me a warning that something is draining the battery. Ever seen this before? Kind of want to have some ideas before I take it into the shop, since this sort of thing can super hard to track down and the shop may not be very interested in spending that kind of time on extended warranty work.

 

do you have an automatic transmission?

 

No, but I did unplugg my usb phone charger that has a LED power indicator, and put the car on the charger. The charger read 56%. Charged it up to 100%. Been driving it for two days and no battery drain warning. Going to drive it for a week or two and then take a reading again. Wondering if the alternator may be about to go out, since I drove it for a week and it still wasn't fully charged.

 

put up the exact warning message as it appears on the screen.

It could be that your 4 year old battery is just done and needs to be replaced.

If so you'll have to re-code the ECU for it if you change the size or type. I just did this with mycarly and it was pretty easy but kind of pricey for the dongle, the app, and the battery registration add-on feature.

 

the reason i asked about an auto trans is they shift so early that the rpm stays to low for the alternator to reach full output

try keeping the rpm at or above 3,000 and the alternator will output more energy for charging the battery ... this has cured the battery drain msg on several auto trans cms

the cigar plug should shut off when the engine is shut off and the key removed ... mine does in my 12 all4 ... i have 3 cigar lighters and each has a 2 port charger in all the time ... they all have pilot lights and they all shut off when thr engine stops

 

Yeah, logically, I was thinking the same thing about the cigarette lighter. I was just trying to eliminate every possibility.

 

the alternator should charge fine at idle. If this helps I'd be thinking you are nursing along an alternator that's about to die.

 

i have suggested keeping the rpms at about 3,000 to several owners having the battery drain warning, all had already had batteries and alternators tested and wete asking for help.

i think city stop and go low speed traffic commute + cold weather (seat heat on, heater fan on high, electric window defroster on, outside mirror heat on, headlights on and phone/ipod/gps playing) + auto trans early shift leads to a non-charging battery condition

manually shifting to keep the rpm near 3,000 has solved the problem for several people

 

Alternators are not like old fashioned generators. They deliver charging at low RPMs that should be more than adequate unless your trips are mostly 10 minutes or less. Any vehicle produced in the past 25 years should be in this category.

 

do you have a voltmeter on your mini? i do have one on my 12 cms all4.

at idle, if i turn on everything,
headlights
heater fan high
seat heaters on high
rear defroster
radio
wipers
fog lights

the voltage is 12.6-12.8, insufficient to charge the battery .... the battery may or may not be discharging at that system voltage but it is definitely not charging

a 12 volt nominal battery requires 13.8 - 14.4 volts to charge

with the above loads on, i do not see 13.8 volts until the rpm reaches 2,400 - 2,700 rpm and do not see 14.4 volts or above until above 3,400 - 3,700 rpm

i deal with alternator loads on aircraft daily, aviation alternators come with output performance charts that plot amps vs rpm and they do not put out rated amps at idle, no alternator does, aviation, automotive or utility

 

Well, why would anyone turn on all those high load drawing accessories and then sit around idling? I'm at or above 2,400 rpm most all the time I'm driving. Your style may be different of course, but it's never been a problem for me even with lots of short trip errands. Maybe the charging rate needs adjustment for winter driving in the case mentioned above? Maybe the "intelligent" battery monitoring system isn't in sync with the battery? Regardless, my statement was generally correct, and I wrote "at low rpms," I didn't specify at idle.

 

just demonstrating that you can in fact use more amps than thr alternator can supply

i have never personally had the problem, i have a manual and like to keep the rpm at or above 3,000 for the throttle response

but many people have posted in the facebook groups, both cm and other models, with the battery drain warning

sime have needed a new battery, but most have an automatic transmission and commute in the city stop and go traffic

under those circumstances it is essy to not keep the battery charged due to the early shift points of the auto trans

going into manual mode and keeping the rpm near 3,000 has solved the problem

 

Ok, good information to know. Thanks.

 

Tested the battery, alternator, and parasitic drain over the weekend. Drain was .06mA, very very low. Alternator pumps out 14-15V at idle, normal. After two weeks from full charge, battery was at 40%.

Car is getting new battery under 30 day warranty.

 

The shop says the battery and alternator, both need to be replaced. I'm like, whatevs. That's what the 30 day warranty is for. I mean, I'll be without my car for several days (no alternator in stock) but hey, what are you going to do?