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Discussion Starter #1
Hey Guys

I was at a local parts store today and just thought I hadnt checked my battrery or anything in about 2 yrs, so I asked them to do a battery test and it came up as Battery being good, but only 18% charged, it was when I had drove it for about 1/2 hr, I am not having any troubleds starting it or anything. The guy at the parts store said it could be car's charging system, but it doesnt make sense to me, if anything was srong with charging system, my battery would have died by now. I dont know where to start.

Any input from you guys would be helpful.

Thanks in advance.
 

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Hey Guys

I was at a local parts store today and just thought I hadnt checked my battrery or anything in about 2 yrs, so I asked them to do a battery test and it came up as Battery being good, but only 18% charged, it was when I had drove it for about 1/2 hr, I am not having any troubleds starting it or anything. The guy at the parts store said it could be car's charging system, but it doesnt make sense to me, if anything was srong with charging system, my battery would have died by now. I dont know where to start.

Any input from you guys would be helpful.

Thanks in advance.
If it was only 18% charged, it would never start the engine. Perhaps 18% discharged?
 

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I recently had a situation where - due to lack of driving my E60 daily and short trips - my battery partially discharged to the point that although it started OK, the voltage drop when the starter was cranking was enough to cause the computer to reset (avg mpg, date, time) and I noticed the radio would cut out. The car drove normally.

I wound up getting a battery tender plus (about $40)... and if I plan to let the car sit for more than a week or two, or if I'm not driving it for more than half hour at a time, I'll hook up the tender and let it sit. The tender trickle charges the battery and "floats" it once charged to keep it fully charged without damaging the cells.

I never had to do this with any other car I've owned, but the E60 has a lot of electronics and some of the circuits draw power even when the car is off. I will mention this to the dealer when I take it in next time. There may be a software update to address the issue.
 

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Freude am Fahren
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Battery might be on its way out and not taking a full charge anymore. Optimate 3 might help, but I'm not sure. +1 for a Battery Tender/Optimate type of thing. These are NOT trickle chargers, but are intelligent and won't blow your battery up.

If the car is running fine and it's 18% discharged, I don't see why there's a problem***8230;18% charged probably wouldn't start the car.
 

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Take note of chart in image below..at 11.89 volts...the battery is at 0% state of charge. If your battery is at 18% state of charge...it is probably putting out somewhere around 12 volts.

When you get consistently BELOW 11.89 volts...that's when the trouble starts and you may find your self stranded. The car battery is designed with an RC (reserve capacity) which helps for brief period to start the car when the battery becomes discharged...but the battery will not be able to keep starting your car or doing it job properly if consistently in a state of discharge.

If you've UNLOCKED your OBC...you can do TEST #9 and check your battery's voltage anytime you desire...it can be done in 10 seconds.

 

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Discussion Starter #6
Take note of chart in image below..at 11.89 volts...the battery is at 0% state of charge. If your battery is at 18% state of charge...it is probably putting out somewhere around 12 volts.

When you get consistently BELOW 11.89 volts...that's when the trouble starts and you may find your self stranded. The car battery is designed with an RC (reserve capacity) which helps for brief period to start the car when the battery becomes discharged...but the battery will not be able to keep starting your car or doing it job properly if consistently in a state of discharge.

If you've UNLOCKED your OBC...you can do TEST #9 and check your battery's voltage anytime you desire...it can be done in 10 seconds.

No I havent Unlocked my OBC yet, and I dont know even know how to do that.

And what I understand since I had just drove the car and didnt follow the procedure to remove the stray charge, I could have been getting wrong information and battery just might be fine without any problems
 

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Freude am Fahren
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Low has a picture of the car with the open doors light up, hi has a message centre that says "Door open" or something like that. Q's got lots of pics; I should start saving them :p. Hi also has "BC" written on the bottommost button on the right side of the radio control. It's pretty neat***8230;has lots of info.

The user's manual has pics of both dashes as well. I assume yours is a low, as it's not a 540
 

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Great explanation ^^^^ thanks

Here's the pics...the LOW MID does NOT have BC written on the bottom right button of the MID (only has the clock face button). See red arrows pointing to the BC icon in image below:



And like BMWnoob13 said...the LOW instrument cluster uses a GRAPHIC DISPLAY...and the HIGH instrument cluster uses a 20-digit alpha/numeric display..the HIGH cluster also has TWO buttons...one is the trip odometer reset button...and the other is the Check Control System button that allows you to scroll thru the Priority Warnings (see owners manual for detailed description):


 
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