5-Series (E12,E28, E34, E39, E60)Chat relating to the BMW 5-Series of all generations. Specific models include: BMW 518, BMW 520, BMW 520i, BMW 530i, BMW 528i, BMW 530i, BMW 518i, BMW 524d, BMW 525i, BMW 525e, BMW 528e, BMW 540i, BMW 535i, BMW 520d, BMW 525td, BMW 525d, BMW 530d, BMW 525i/xi, BMW 530i/xi. (BMW 5-Series Forum)
Hi all, hopefully someone will be able to help me out here. I have been having problems with my 2005 E60 525 where every morning the battery is completely flat. After searching on this site I have learnt that this is not an uncommon problem. Reasons varying from the IBS, Hedgehog and the comfort system( or something like that). Following guidance i borrowed a multimeter and carried out a drain test which showed a huge reading of 5 amps. I believe it should be around 0.03 amps. So before i put it into a rather expensive dealer can anyone suggest what might be causing such a large drain. Thanks in advance.
After how many minutes was the amperage this high? Different modules/busses go to sleep at different times. it can take up to 70 minutes for everything to go completely to sleep. Without dealer equipment to point you in the right direction of what is causing the draw for example frequent wakeups or modules not assuming sleep mode etc then these problems can be near impossible to find. If you dont have a very good understanding of all of the systes and how they work then the troubleshooting is best left to professionals. One thing you can do is try disconnecting any aftermarket equipment if you have any installed and also any ipod or phone chargers etc.
Look at the basics first for example maybe the glovebox light stays on after you close it or the underhood light stays on (if it has one??) or the trunk light stays on or if you have a car cell phone charger or somethin that doesnt belong to the car.. after that your probably looking at what Dirty_Tool said or other things like shorted circuits and stuff... also if you have an aftermarket stereo then that maybe an installation problem
Thanks for your replies. I have monitored the drain 20 mins after switching off believing that thus is long enough to put the car into sleep mode. After this amount of time the drain reads 3.5 amps. I have no after market products fitted.
I'm going to take it into the local dealer tomorrow and see if they can help.
20 mins is not long enough for all of the busses to go to sleep. 3.5 amps would be fairly normal after that amount of time. Good luck at the dealer. Be sure to update your post and let everyone know what the resolution was.
Ok time for an update. Apologies for the delay but i have been away from the car for the last few weeks due to work. I took the car into the so called BMW specialist who did a full diagnostic check after charging the battery. He told me that no fault codes were reported.
Before departing for the last few weeks i disconnected the neg lead. On return reconnected the lead and the car started first time. After doing a little reading i disconnected what i believe what is the intelligent battery sensor lead from the battery negative lead. I think there is a fault with this which was stopping the car going into sleep mode and hence draining the battery over night. This seemed to solve my problem although now when starting the car occasionally it cranks for a very long time before starting. Therefore my next question is what exactly does the IBS lead do?
The AutoGuide.com network consists of the largest network of enthusiast-owned enthusiast-operated automotive communities.
AutoGuide.com provides the latest car reviews, auto show coverage, new car prices, and automotive news. The AutoGuide network operates more than 100 automotive forums where our users consult peers for shopping information and advice, and share opinions as a community.