Battery discharge when stationary

[vigilante]

Hi guys,

I know its been asked many times but i have gone through the forums and could not find a solution. So my car was running fine and i dropped it for PPF coating when i went on vacation. I came back after 15 days and collected the car. Drove home no issues. Next morning i start the car and it says increased battery discharge and the car wont start. So i jump started it and let it warm up but i left it it home on a battery charger and went to work.. Came home started the car and it drove fine parked it overnight and the same thing happened the next morning. I put it again on the battery charger and it started ok in the evening but again in the morning battery drained and increased battery discharge message. During the night the alarm also goes off and i have to go and put the charger on as the car wont unlock as it seems the battery is too low. I have tried disconnecting all the door handle comfort access connections and it didnt help. I have noticed burn marks on the jump terminal under the hood.

Please advise what i should look into next.

Btw i have already changed the battery also in trying to resolve the issue.

Thanks

[crazyinp]

Originally Posted by vigilante

Hi guys,

I know its been asked many times but i have gone through the forums and could not find a solution. So my car was running fine and i dropped it for PPF coating when i went on vacation. I came back after 15 days and collected the car. Drove home no issues. Next morning i start the car and it says increased battery discharge and the car wont start. So i jump started it and let it warm up but i left it it home on a battery charger and went to work.. Came home started the car and it drove fine parked it overnight and the same thing happened the next morning. I put it again on the battery charger and it started ok in the evening but again in the morning battery drained and increased battery discharge message. During the night the alarm also goes off and i have to go and put the charger on as the car wont unlock as it seems the battery is too low. I have tried disconnecting all the door handle comfort access connections and it didnt help. I have noticed burn marks on the jump terminal under the hood.

Please advise what i should look into next.

Btw i have already changed the battery also in trying to resolve the issue.

Thanks

Check if you are actually charging it. You can use voltmeter or if you have ISTA you can connect and run check. When you change the battery, did you register the new battery or you just did swap? What battery did you use?

[vigilante]

Originally Posted by crazyinp

Check if you are actually charging it. You can use voltmeter or if you have ISTA you can connect and run check. When you change the battery, did you register the new battery or you just did swap? What battery did you use?

Thanks for the response.

The battery tender that I have shows that the battery is charging. When its drained it shows 9.5v or less and when i charge it after 3-4 hours it shows 13v-14v and the car starts on the touch of the start button. I am using ac delco 100amp battery and I have registered it using ISTA.

[M5Rick]

I would never hand over car to non BMW people for such a long time, all types can roam around the car and may interfere with stuff on it.

[crazyinp]

Originally Posted by vigilante

Thanks for the response.

The battery tender that I have shows that the battery is charging. When its drained it shows 9.5v or less and when i charge it after 3-4 hours it shows 13v-14v and the car starts on the touch of the start button. I am using ac delco 100amp battery and I have registered it using ISTA.

What is the voltage when car is running. Is it actually charging? If it does, better start looking what is draining your battery. I have no experience with it before but reading that CAS is common to drain the car when you have bad handle

[m5rosco]

My previous and current F10 M5's have both shown the battery discharge when stationary error message on start up. Both of them were down to a failing comfort access handle.

[vigilante]

Today we tried everything. Took off all 4 door handle and still it showed a parasitic drain of .4 amps

We tried pulling all fuses one by one while the voltmeter was connected in series and still we had constant .4 amps of drain.

I also tried disconnecting the ibs sensor grip from the negative terminal and still the same.

What am i doing wrong??

[vigilante]

Ok so found a connector for the door light disconnected and just connected it back on. Could the disconnection be drawing the current? Lets hope it was the issue. Will know in the morning but could that be it. Someone told me if anything is left disconnected on a bmw it draws current and drains the battery. Is that true?

[vigilante]

Ok so that was not it and the drain remained. So we kept checking and finally i have found that one of the auxiliary coolant pump is continously on and never goes to sleep even after 3 hours. If i disconnect its connector the battery stops drawing current. Where is the module that controls this pump. What should i look for??