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Parasitic battery drain - X5 35d
Parasitic battery drain - X5 35d
Hi guys every time I start the car the clock resets so I thought I'd call AA they said theres a drain of 7amps while the car is switched off. Any ideas where I need to look, the battery was replaced 2.5 years ago with with a Bosch S4.
Parasitic battery drain - X5 35d
That’s a significant drain. A code read might find it but otherwise it’s a case of pulling fuses unfortunately. One thought that spring to mind is the hedgehog. Same issue that the E53 has. The blower regulator is on the main fan unit. Pulling the climate control fuses might find if that is the cause.
Never anthropomorphise computers. They hate that.Parasitic battery drain - X5 35d
Personally I wouldn't rule out the battery actually being faulty too if its been sitting at home on a low charge with the pandemic this last 2 years
Parasitic battery drain - X5 35d
I personally think the battery is faulty but it was provided by AA, because soon as I turn off the ignition after a minute it so the battery warning comes up. Going bsck to X5sport, currently the heater blower motor is causing issues it is intermittent it speeds up and down and some days does not work.
Parasitic battery drain - X5 35d
If the heater blower is revving up and down it definitely needs the resistor/hedgehog changing first or even disconnected to rule it out but I've had a battery fail in 6 months in the past 
Parasitic battery drain - X5 35d
That is exactly what it's doing revving up and down. I also think the battery is failing as soon as I switch off the car, the steering wheels moves back in its sleep position and battery warning comes on. Is heater resister known to drain the battery if faulty?
Parasitic battery drain - X5 35d
Before you get too far into fault-finding, is your battery fully charged? A fully charged battery should show 13.2V DC on a voltmeter with the car asleep or the battery disconnected.
To answer your question - The hedgehog (Final Stage Resistor) was known to cause issues on the E53 with the internal fan sometimes continuing to run after switch off. It also kept the tell-tale ‘P’ symbol lit on the gearshift. I don’t know what the tell-tale is on the E70 and newer. Could be the handbrake LED though. It should go out after 15 mins.
If you have a voltmeter then see what the reading is from the jump points under the bonnet with the engine running. It should be at least 13.8V DC for a ‘wet’ battery and 14.4V DC for an AGM type (the battery should say AGM on the top). If the voltage is less than those two that points at an alternator issue.
Then take the measurement again with the engine off. If it drops rapidly (especially to below 12V) then that points to a cell having failed.
To prove the battery, disconnect it from the car and see what the voltage readout (preferably when fully charged) is and then what is does over several hours. If it falls below 12V it’s toast.
When the AA changed the battery, did they recode the car? You have the Intelligent Battery System (IBS) and that needs coding at a battery change. The system has to be told what type and rating of battery was installed. If that wasn’t done then your car will be mis-charging the battery and that will shorten its service life.
Note that a parasitic drain within the battery will not show up as a 7A current as you report. Internal battery faults appear as a loss of charge capacity (inability to store and hold a charge). If you have had a 7A current draw found, that points at an issue within the car electrical system. A diagnostic check should identify which system is affected. I had a device plugged into the glovebox USB point on my X6 and computer recorded it as a fault as it kept the car system awake. It wasn’t much of a draw (a few mA) but it was still recorded by the computer.
To answer your question - The hedgehog (Final Stage Resistor) was known to cause issues on the E53 with the internal fan sometimes continuing to run after switch off. It also kept the tell-tale ‘P’ symbol lit on the gearshift. I don’t know what the tell-tale is on the E70 and newer. Could be the handbrake LED though. It should go out after 15 mins.
If you have a voltmeter then see what the reading is from the jump points under the bonnet with the engine running. It should be at least 13.8V DC for a ‘wet’ battery and 14.4V DC for an AGM type (the battery should say AGM on the top). If the voltage is less than those two that points at an alternator issue.
Then take the measurement again with the engine off. If it drops rapidly (especially to below 12V) then that points to a cell having failed.
To prove the battery, disconnect it from the car and see what the voltage readout (preferably when fully charged) is and then what is does over several hours. If it falls below 12V it’s toast.
When the AA changed the battery, did they recode the car? You have the Intelligent Battery System (IBS) and that needs coding at a battery change. The system has to be told what type and rating of battery was installed. If that wasn’t done then your car will be mis-charging the battery and that will shorten its service life.
Note that a parasitic drain within the battery will not show up as a 7A current as you report. Internal battery faults appear as a loss of charge capacity (inability to store and hold a charge). If you have had a 7A current draw found, that points at an issue within the car electrical system. A diagnostic check should identify which system is affected. I had a device plugged into the glovebox USB point on my X6 and computer recorded it as a fault as it kept the car system awake. It wasn’t much of a draw (a few mA) but it was still recorded by the computer.
Never anthropomorphise computers. They hate that.Parasitic battery drain - X5 35d
Thanks X5 I will keep those things you listed in mind. Looking back when the battery was changed it wasn't coded in that much I can recall. Personally I do feel the battery isn't holding charge. It needs further investigation, have booked it in with my local indy. I'm not very hands on with these things and don't have the tools.