Battery Voltage is dropping to 11V overnight
12-08-2013, 09:32 AM
#11
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Tried to jump start the car with no success 
. I didn't clean the terminals on my 2nd car battery though. They started to corrode. My cables may be gone bad as well I don't know. At least I managed to register the new battery in INPA.
It turns the engine but not enough compression to ignite I'll give it another try after I clean my Honda's battery terminal.
I've got a question, should the aiding car (which is in running condition) be powerful as jumped car in order to be able start the engine at first try?
Shouldn't a running car be able to provide enough juice given that it's another diesel which also powerful?
. I didn't clean the terminals on my 2nd car battery though. They started to corrode. My cables may be gone bad as well I don't know. At least I managed to register the new battery in INPA.It turns the engine but not enough compression to ignite
I'll give it another try after I clean my Honda's battery terminal. I've got a question, should the aiding car (which is in running condition) be powerful as jumped car in order to be able start the engine at first try?
Shouldn't a running car be able to provide enough juice given that it's another diesel which also powerful?
You should try to get to the bottom of the problem soon. Attaching a fully discharged battery to an alternator (especially an older one) has the potential to damage it. Not only is the BMW alternator being stressed when it finally starts with a battery at 11.8V, but the Honda alternator is really being stressed trying to power itself, charge its own battery, charge the BMW battery, power the BMW computers and supply cranking power to the BMW starter. Lots of stress.
The main question is do you ever see the new BMW battery reach a full charge of 12.5V+ after driving?
12-08-2013, 10:51 AM
#12
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Guys, I found the culprit to my problem. It is the cable which BMW recalled 1.5 million cars for cable replacement. It's getting really really hot and there is a damage on it. I heard a "bang" while I was driving and singing 
. Then started the Christmas tree on the dashboard. When I opened the trunk I saw that cable in the picture was detached from the tip of the arrow.
I then did a potentially fatal mistake, I just forced the cable back in without securing it
. So I thought I was connecting as it should be. That was the reason I was getting different readings when I measuring with voltmeter where the arrow is and the battery terminal.
Anyway, I'll go to BMW service tomorrow and get it replaced immediately. I'll try to return the voltage regulator I bought. There is a 7days return no questions asked law here.
I know that my trunk does not look like a healthy place for a battery. Battery is currently not fixed and if go over the sleeping policemen it can jump and cause damage to itself. It can also cause a fire!!!!
Please learn from my mistake/experience and take care of this serious problem. That cable is getting very very HOT.
. Then started the Christmas tree on the dashboard. When I opened the trunk I saw that cable in the picture was detached from the tip of the arrow.I then did a potentially fatal mistake, I just forced the cable back in without securing it
. So I thought I was connecting as it should be. That was the reason I was getting different readings when I measuring with voltmeter where the arrow is and the battery terminal. Anyway, I'll go to BMW service tomorrow and get it replaced immediately. I'll try to return the voltage regulator I bought. There is a 7days return no questions asked law here.
I know that my trunk does not look like a healthy place for a battery. Battery is currently not fixed and if go over the sleeping policemen it can jump and cause damage to itself. It can also cause a fire!!!!
Please learn from my mistake/experience and take care of this serious problem. That cable is getting very very HOT.
12-09-2013, 03:58 AM
#15
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Hi roswell
Have you check the cable where it goes throug the trunk flor ! ! ! , it's a known issue that ( safty bullitin have been send out from BMW last year here in Europe ) it is the fitting that go throug the floor an connects the positiv cable inside with the one on the outside ( going forward to the starter and engine compartment ) , it can get defect ( shortcut to ground ) and drain a lot of power and also course a FIRE in the car !
Can also give the faliur of the BST modul as you mentioned here !
So get this checked as soon as possible !
Have you check the cable where it goes throug the trunk flor ! ! ! , it's a known issue that ( safty bullitin have been send out from BMW last year here in Europe ) it is the fitting that go throug the floor an connects the positiv cable inside with the one on the outside ( going forward to the starter and engine compartment ) , it can get defect ( shortcut to ground ) and drain a lot of power and also course a FIRE in the car !
Can also give the faliur of the BST modul as you mentioned here !
So get this checked as soon as possible !
Last edited by BenAnd; 12-09-2013 at 04:02 AM.
12-10-2013, 08:25 AM
#16
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IBS monitors battery temperature, voltage, and current draw and stores these at some sample interval. These are used to calculate State of Health (SoH), and State of Charge (SoC).
Battery voltage output is dependant on temperature due to the chemical reaction changes and load current due the I2R losses across the plates.
IBS creates a "chart" of sorts and monitors battery state of charge and passes that information via the BSD (Bit Serial Data) interface to the DME. The alternator is also connected to the BSD for the purpose of allowing the DME to control output voltage. Alternator output voltage is what determines if the battery is charging or not (if Eg > Vt where Eg is alternator output and Vt is battery voltage) and will place the battery in a non-charging stated based on a few conditions. This is done for several reasons, one being to prolong the life of the cells as lead-acid batteries degrade faster on constant trickle charges due to degradation of the active (lead) material from the structural grid (usually an alloy with lead) it is pressed onto causing shedding. Also, alternators producing charge current require torque, that torque comes from the engine resulting in less power availbable and decreased fuel economy.
Not registering a new battery in IBS fails to wipe the historical data associated with the old battery. This results in a measured Vt for the new battery higher than what is excected, so the IBS falsely believes that the old battery must be at a higher SoC than the new one and the DME instructs the alternator not to charge it. This has resulted in people driving along for a few minutes and getting random electrical errors due to the battery providing all the load and dropping voltage quicker than the DME responds the ramp up alternator voltage.
This is also why any variation in battery from what the car came with requires programming. AGM, wet cell, as well as other types of batteries have different charging characteristics and not updating the DME with the correct type can lead to less than optimal and possibly detrimental charging parameters.
These cars have remarkably complex electrical systems that can be remarkably frustrating to troubleshoot something that used to be so simple.
Last edited by jcolley; 12-10-2013 at 08:28 AM.
12-10-2013, 09:07 AM
#17
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So what are the ramifications of temporarily unplugging the IBS to see if it's faulty and slowly draining the battery? What if the IBS is not the issue? Would unplugging it cause more problems?
Last edited by balbs; 12-10-2013 at 10:24 AM.
12-10-2013, 10:05 AM
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If IBS is preventing the system from going to sleep, there will be an "increased battery discharge" error in iDrive when Terminal 15 power comes on. Unplugging the BSD line connector from the IBS sensors may cause BSD bus faults to be stored, but I'm not certain if it will prevent the modules from going to sleep.
I'll have to look through the E60 training docs.
I'll have to look through the E60 training docs.
12-10-2013, 10:13 AM
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Don't have time to sift through it right now, but here's a great primer on the Helbako IBS manufactured for BMW.
10_E60 Voltage Supply and Bus Systems.pdf
10_E60 Voltage Supply and Bus Systems.pdf
12-10-2013, 01:39 PM
#20
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Not exactly true.
IBS monitors battery temperature, voltage, and current draw and stores these at some sample interval. These are used to calculate State of Health (SoH), and State of Charge (SoC).
Battery voltage output is dependant on temperature due to the chemical reaction changes and load current due the I2R losses across the plates.
IBS creates a "chart" of sorts and monitors battery state of charge and passes that information via the BSD (Bit Serial Data) interface to the DME. The alternator is also connected to the BSD for the purpose of allowing the DME to control output voltage. Alternator output voltage is what determines if the battery is charging or not (if Eg > Vt where Eg is alternator output and Vt is battery voltage) and will place the battery in a non-charging stated based on a few conditions. This is done for several reasons, one being to prolong the life of the cells as lead-acid batteries degrade faster on constant trickle charges due to degradation of the active (lead) material from the structural grid (usually an alloy with lead) it is pressed onto causing shedding. Also, alternators producing charge current require torque, that torque comes from the engine resulting in less power availbable and decreased fuel economy.
Not registering a new battery in IBS fails to wipe the historical data associated with the old battery. This results in a measured Vt for the new battery higher than what is excected, so the IBS falsely believes that the old battery must be at a higher SoC than the new one and the DME instructs the alternator not to charge it. This has resulted in people driving along for a few minutes and getting random electrical errors due to the battery providing all the load and dropping voltage quicker than the DME responds the ramp up alternator voltage.
This is also why any variation in battery from what the car came with requires programming. AGM, wet cell, as well as other types of batteries have different charging characteristics and not updating the DME with the correct type can lead to less than optimal and possibly detrimental charging parameters.
These cars have remarkably complex electrical systems that can be remarkably frustrating to troubleshoot something that used to be so simple.
IBS monitors battery temperature, voltage, and current draw and stores these at some sample interval. These are used to calculate State of Health (SoH), and State of Charge (SoC).
Battery voltage output is dependant on temperature due to the chemical reaction changes and load current due the I2R losses across the plates.
IBS creates a "chart" of sorts and monitors battery state of charge and passes that information via the BSD (Bit Serial Data) interface to the DME. The alternator is also connected to the BSD for the purpose of allowing the DME to control output voltage. Alternator output voltage is what determines if the battery is charging or not (if Eg > Vt where Eg is alternator output and Vt is battery voltage) and will place the battery in a non-charging stated based on a few conditions. This is done for several reasons, one being to prolong the life of the cells as lead-acid batteries degrade faster on constant trickle charges due to degradation of the active (lead) material from the structural grid (usually an alloy with lead) it is pressed onto causing shedding. Also, alternators producing charge current require torque, that torque comes from the engine resulting in less power availbable and decreased fuel economy.
Not registering a new battery in IBS fails to wipe the historical data associated with the old battery. This results in a measured Vt for the new battery higher than what is excected, so the IBS falsely believes that the old battery must be at a higher SoC than the new one and the DME instructs the alternator not to charge it. This has resulted in people driving along for a few minutes and getting random electrical errors due to the battery providing all the load and dropping voltage quicker than the DME responds the ramp up alternator voltage.
This is also why any variation in battery from what the car came with requires programming. AGM, wet cell, as well as other types of batteries have different charging characteristics and not updating the DME with the correct type can lead to less than optimal and possibly detrimental charging parameters.
These cars have remarkably complex electrical systems that can be remarkably frustrating to troubleshoot something that used to be so simple.
I agree that the IBS communicating with the DME allows the DME to communicate with the alternator and vary the output voltage.
However, the OPs question was as follows:
Can it be that IBS sensor detected that my old battery cannot be charged anymore and it is not letting alternator charge the battery?
So since I have not registered the new battery could it be IBS simply blocking alternator from recharging the battery by not completing the circuit on the negative terminal?
As you know, the IBS is not connected to the positive cable power line, nor does it control any type of breaker or relay that gives the IBS the control to completely interrupt charging of the battery. The minimum output of the alternator will always reach the battery (short of the BST activating).
If what you say is true, then when "the battery is placed in a non-charging state" the voltage across the battery terminals would be 12.6V or less. This is never the case while the alternator is operating.
Voltage variation from the alternator is temperature related to prevent degassing the battery but alternator minimum output is never interrupted to the battery.