Battery dies overnight
11-04-2009, 07:37 PM
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The battery on my 545 is dead overnight. It is driven more then enough everyday to keep the battery charged. I even charged the battery and reinstalled it same thing battery dead next morning. What should normal amperage be for this car when it is sleeping? When I first read the amperage it is around 5 amps. All the trunk lights and interior lights are off. Then after a couple hours it drops to 3. I checked voltage across all the fuses in the trunk and glovebox. No voltage drops found. I then pulled each fuse looking for a drop in the ammeter reading. I found when pulling the ignition fuses in the glove box number ignition fuse 7 and 15 and the radio fuse 34 the ammeter drops to .84-1.4 amps. All three fuses need to be pulled to get the amps to drop. I left the fuses out and reconnected the battery to see if the voltage drops overnight again.
This morning the battery was dead. There where a couple other fuse that when pulled resulted in a very slight amp draw change.
Anyone know where to go next? Anywhere I can get wiring prints and manuals for the car?
Thanks.
Craig
This morning the battery was dead. There where a couple other fuse that when pulled resulted in a very slight amp draw change.
Anyone know where to go next? Anywhere I can get wiring prints and manuals for the car?
Thanks.
Craig
11-04-2009, 07:45 PM
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pulling the fuses are a good step to see if something is sucking juice. have you tried charging the battery, making sure you can start the car, and then leave it over night to see if you can start it the next morning?
michael
michael
Originally Posted by skibarefoot' post='1047539' date='Nov 4 2009, 08:37 PM
The battery on my 545 is dead overnight. It is driven more then enough everyday to keep the battery charged. I even charged the battery and reinstalled it same thing battery dead next morning. What should normal amperage be for this car when it is sleeping? When I first read the amperage it is around 5 amps. All the trunk lights and interior lights are off. Then after a couple hours it drops to 3. I checked voltage across all the fuses in the trunk and glovebox. No voltage drops found. I then pulled each fuse looking for a drop in the ammeter reading. I found when pulling the ignition fuses in the glove box number ignition fuse 7 and 15 and the radio fuse 34 the ammeter drops to .84-1.4 amps. All three fuses need to be pulled to get the amps to drop. I left the fuses out and reconnected the battery to see if the voltage drops overnight again.
This morning the battery was dead. There where a couple other fuse that when pulled resulted in a very slight amp draw change.
Anyone know where to go next? Anywhere I can get wiring prints and manuals for the car?
Thanks.
Craig
This morning the battery was dead. There where a couple other fuse that when pulled resulted in a very slight amp draw change.
Anyone know where to go next? Anywhere I can get wiring prints and manuals for the car?
Thanks.
Craig
11-04-2009, 07:54 PM
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Originally Posted by skibarefoot' post='1047539' date='Nov 4 2009, 11:37 PM
The battery on my 545 is dead overnight. It is driven more then enough everyday to keep the battery charged. I even charged the battery and reinstalled it same thing battery dead next morning. What should normal amperage be for this car when it is sleeping? When I first read the amperage it is around 5 amps. All the trunk lights and interior lights are off. Then after a couple hours it drops to 3. I checked voltage across all the fuses in the trunk and glovebox. No voltage drops found. I then pulled each fuse looking for a drop in the ammeter reading. I found when pulling the ignition fuses in the glove box number ignition fuse 7 and 15 and the radio fuse 34 the ammeter drops to .84-1.4 amps. All three fuses need to be pulled to get the amps to drop. I left the fuses out and reconnected the battery to see if the voltage drops overnight again.
This morning the battery was dead. There where a couple other fuse that when pulled resulted in a very slight amp draw change.
Anyone know where to go next? Anywhere I can get wiring prints and manuals for the car?
Thanks.
Craig
This morning the battery was dead. There where a couple other fuse that when pulled resulted in a very slight amp draw change.
Anyone know where to go next? Anywhere I can get wiring prints and manuals for the car?
Thanks.
Craig
11-04-2009, 07:58 PM
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oh okay that's not the test i wanted you to run but since you already checked the alternator then nevermind. 
what's the voltage like?
michael
what's the voltage like?
michael
Originally Posted by skibarefoot' post='1047568' date='Nov 4 2009, 08:54 PM
Yup, battery has been charged many times, the car starts fine and runs without incident all day. When parked for the evening the next morning the battery is dead again. I even had the alternator tested and it is charging OK and diodes check OK.
11-04-2009, 08:06 PM
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Originally Posted by acuteperformance' post='1047571' date='Nov 4 2009, 11:58 PM
oh okay that's not the test i wanted you to run but since you already checked the alternator then nevermind.
what's the voltage like?
michael
what's the voltage like?
michael
11-04-2009, 08:10 PM
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let's see what happens with the fuses pulled out then.
Originally Posted by skibarefoot' post='1047576' date='Nov 4 2009, 09:06 PM
Alternator output or battery charged voltage? The battery is new, changed it before really troubleshooting. When charged it is 13.5 volts. Alternator output is 14.5. I haven't measured it for awhile so the output voltage may be off. When the car is jump started then driven the battery comes back charged.
11-04-2009, 08:19 PM
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Originally Posted by acuteperformance' post='1047580' date='Nov 5 2009, 12:10 AM
let's see what happens with the fuses pulled out then.
With the fuses out the amp draw drop down to .84-1.5. Yes it varies. With the fuses in it's pretty steady. I left the fuses out last night the the battey went from 11 volts (low due to troubleshootin) to 6volts in about 5 hours. This morning I disconnected the battery and charged it. Right now the car is in the following configutation.
Battery disconnected
Ignition fuses and radio fuse out
Trunk is open and latched to keep the light out
Passenger door open and latched to keep the light out
Glove box open and the light unplugged
We have another BMW to drive E36. The car has been sitting these past couple of days for troubleshooting.
11-04-2009, 08:54 PM
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My Ride: 04 545i sport, stick, L7, sat, nav. Charcoal/ runflat/ cdv delete.
Suede headliner/ trunk, 3 way front speakers, four 8" subs in rear shelf, ACM, iPod dock in ash tray using gateway 500 with MP3 text and video on screen, MRTM aluminum pedals/ door pins, 10 farad cap, sound processor, line conditioner, 2 amps ( 4x100 and 2x200)
Just curious what your using to measure current draw? Something similar to this?
11-04-2009, 09:03 PM
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Originally Posted by methodsound' post='1047644' date='Nov 5 2009, 12:54 AM
Just curious what your using to measure current draw? Something similar to this?
Digital multimeter set on the dc 10a scale. Discount neg bat cable and place the leads between the neg battery post and the neg cable.
11-04-2009, 09:47 PM
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My Ride: 04 545i sport, stick, L7, sat, nav. Charcoal/ runflat/ cdv delete.
Suede headliner/ trunk, 3 way front speakers, four 8" subs in rear shelf, ACM, iPod dock in ash tray using gateway 500 with MP3 text and video on screen, MRTM aluminum pedals/ door pins, 10 farad cap, sound processor, line conditioner, 2 amps ( 4x100 and 2x200)
Originally Posted by skibarefoot' post='1047654' date='Nov 4 2009, 10:03 PM
Digital multimeter set on the dc 10a scale. Discount neg bat cable and place the leads between the neg battery post and the neg cable.
I use the adaptor so I do not have to worry about the fuse in the DMM. Either way, an acceptable draw would be around 40 milli amps.
Is your car able to go to sleep? It should sleep after about 16-26 minutes with all triggers closed and no activity.