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E85 LONG RUNNING BATTERY DRAIN - NEED HELP IN FINDING A COMPANY WHO CAN IDENTIFY PROBLEM

Discuss problems you have had or are having with your Z4
longleydel
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E85 LONG RUNNING BATTERY DRAIN - NEED HELP IN FINDING A COMPANY WHO CAN IDENTIFY PROBLEM

Post by longleydel » Sun May 08, 2022 9:01 pm

Can anyone recommend a company in the area around north Kent (SE England) who have expertise/experience in solving BMW electrical issues please?

I have a mysterious, and what appears to be intermittent, long-running battery drain issue on my 2005 E85 3.0 litre Z4. An auto electrician has investigated and tested the car thoroughly 3 hrs plus) and concluded the problem appears to lie with either the climate control/heater unit located in the dashboard, or possibly the heater blower resistor (or ‘Hedgehog’) located I understand behind the glove box. I note from the Forum other owners have identified these as causing a drained battery.

All relevant fuses powering these items were removed (including removing one at a time during the testing process to help try and isolate the problem). I have continued to monitor any potential battery drain. The problem continues to persist however, and I’m still no closer to identifying the problem.

I bought the car privately last summer and experienced flat battery issues, fairly soon afterwards, on a regular basis. The battery is usually flat after 3 to 4 days from being fully charged (engine unable to turn over). I replaced the battery (Bosch 096) in August last year and again (another Bosch under warranty) in early April this year (constant charging – NOCO Genius 5 trickle charger – and occasional jump starting may well have ‘killed’ the last battery). I have been using a TopDon BT100 battery tester over the few months to keep a close eye on battery health and performance.

The fuse that would power the phone/Satnav has also been removed (no Satnav is fitted however) in case a phone was installed in the past, but subsequently removed. The Forum mentions problems with phone tec fitted within the vehicle trying to locate the phone thus draining the battery.

I have checked things like the boot and glove box lights are turning off and the light in the compartment behind the seats is turning off.

In connection with trackers, is there a ‘favourite’ place in Z4’s where these could be located? I have done some searching, but haven’t been able to locate anything that looks like one.

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E85 LONG RUNNING BATTERY DRAIN - NEED HELP IN FINDING A COMPANY WHO CAN IDENTIFY PROBLEM

Post by MKZ4000 » Sun May 08, 2022 9:08 pm

Could try H&C motors in Maidstone.

Not a fix, but you could fit a battery disconnect switch to the negative terminal of the battery.

Clock will need resetting each time if that bothers you.
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E85 LONG RUNNING BATTERY DRAIN - NEED HELP IN FINDING A COMPANY WHO CAN IDENTIFY PROBLEM

Post by bigwinn » Sun May 08, 2022 9:10 pm

Derek

Sounds like you have already done a load of stuff with people more qualified than I am

Whenever I’ve had drain issues I put a volt/ammeter in line with the battery neutral, first to see see the constant drain being put on the system. It’s worth a google to see what the resting state amps should be: versus what your car is draining.

Then with a helper pull each fuse in turn until you find the offending circuit.

It’s worked for me on an E30 with a whopping drain that turned out to be the OBC

Cheers

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E85 LONG RUNNING BATTERY DRAIN - NEED HELP IN FINDING A COMPANY WHO CAN IDENTIFY PROBLEM

Post by longleydel » Sun May 08, 2022 9:23 pm

Thanks, I'll do some research into H&C Motors. Not keen on fitting a cut off switch. I want to keep the car completely original (just under 42,000 miles form new and only 3 owners including myself). Also, I believe continue battery disconnection isn't good for certain sysyems on the car and may require resetting occasionally.

Thanks Stuart, I'm not overly familiar with car electrics (though learning quite quickly given this problem) and uncertain about using a voltmeter correctly as you suggest. Also, the auto electrician seemed to think the problem was intermittant making it quite easy to miss by testing in the way you suggest.

Thanks again both for your thoughts.

Derek

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E85 LONG RUNNING BATTERY DRAIN - NEED HELP IN FINDING A COMPANY WHO CAN IDENTIFY PROBLEM

Post by markplant » Sun May 08, 2022 10:25 pm

Do you garage the car but leave it unlocked, iirc some systems won't go to sleep unless the car is locked
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E85 LONG RUNNING BATTERY DRAIN - NEED HELP IN FINDING A COMPANY WHO CAN IDENTIFY PROBLEM

Post by Smartbear » Sun May 08, 2022 10:30 pm

markplant wrote: Sun May 08, 2022 10:25 pm Do you garage the car but leave it unlocked, iirc some systems won't go to sleep unless the car is locked
They do but it takes longer :thumbsup:
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E85 LONG RUNNING BATTERY DRAIN - NEED HELP IN FINDING A COMPANY WHO CAN IDENTIFY PROBLEM

Post by Motionblurrr » Sun May 08, 2022 11:00 pm

I never had a dead battery from a random drain but I did discover the bulb inside the center console (in between/behind the seats)would never turn off even when I turned the car off. Thankfully I had an LED in there but I took it out due to fear of it draining the battery when I needed it the most.

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E85 LONG RUNNING BATTERY DRAIN - NEED HELP IN FINDING A COMPANY WHO CAN IDENTIFY PROBLEM

Post by Ewazix » Mon May 09, 2022 7:00 am

Your auto electrician identified the hedgehog as suspect, was it changed? If not I'd definitely eliminate this. Otherwise Bigwinn's plan is the way to go.
So many of these faults end up being aftermarket roof modules, Bluetooth kit installs or radio head units going down the percentages suggest those are the areas to look at.
Let us know how it goes.
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E85 LONG RUNNING BATTERY DRAIN - NEED HELP IN FINDING A COMPANY WHO CAN IDENTIFY PROBLEM

Post by longleydel » Mon May 09, 2022 9:38 am

Thanks everyone for your helpful advice. Car isn't garaged unfortunately, but carefully covered and therefore always locked/alarmed. Light in centre console does turn off.

Ive had the 40 amp fuse (No. 57) for the main blower and therefore the resistor (hedgehog) removed over the last few weeks, but still the battery has sufficiently and unable to start car.

Spoke to the autoelectrican this morning and now plan to remove all of the so-called 'hot' fuses (recently found that diagram on the Forum - thank goodness for the Forum), monitor any drain and replace gradually. Presumably any aftermarket bluetooth kit must be linked to a 'hot' fuse otherwise any drain wouldn't occur when vehicle is locked.

If the problem still exists after all of that, will have to start looking again for a tracker. I understand these are really difficult to locate.

Thanks again for your help.

Derek

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E85 LONG RUNNING BATTERY DRAIN - NEED HELP IN FINDING A COMPANY WHO CAN IDENTIFY PROBLEM

Post by SonnyA85 » Wed May 11, 2022 12:22 am

How often do you drive the car? How many miles does it do per year?

You say this is a low mileage only done 40k miles.

I think you are the problem not the car. You aren't driving it enough.

When you aren't driving it. How often do you charge it? Is it once a month? Be honest how long have you let it go between charges?

Once a battery goes below 12v it's knackered. It doesn't matter if you charge it up again it's lost a lot of its power. Then every time it goes below 12v it will get worse and worse til eventually it won't start the car at all.

I charge my car every weekend. And I mean every weekend all the way to full. I literally just charged it a few days ago and it was at 80% but still took majority of the day to charge. It's a brand new battery only just replaced a month or two back and I bought top of the line Bosch because I also don't drive much so wanted biggest battery so it doesn't go flat after a couple of days. This is my third battery for the car in 6 years. I have learned this the hard way.

It's pointless trying to find a power draw if the battery is knackered. Test the battery and see how much charge it is holding. What's the cranking amps? If battery is still in good condition then it's car issue otherwise if battery isn't holding its full capacity then it's your usage that's the issue.

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E85 LONG RUNNING BATTERY DRAIN - NEED HELP IN FINDING A COMPANY WHO CAN IDENTIFY PROBLEM

Post by Ewazix » Wed May 11, 2022 8:12 am

SonnyA85 wrote: Wed May 11, 2022 12:22 am How often do you drive the car? How many miles does it do per year?

You say this is a low mileage only done 40k miles.

I think you are the problem not the car. You aren't driving it enough.

When you aren't driving it. How often do you charge it? Is it once a month? Be honest how long have you let it go between charges?

Once a battery goes below 12v it's knackered. It doesn't matter if you charge it up again it's lost a lot of its power. Then every time it goes below 12v it will get worse and worse til eventually it won't start the car at all.

I charge my car every weekend. And I mean every weekend all the way to full. I literally just charged it a few days ago and it was at 80% but still took majority of the day to charge. It's a brand new battery only just replaced a month or two back and I bought top of the line Bosch because I also don't drive much so wanted biggest battery so it doesn't go flat after a couple of days. This is my third battery for the car in 6 years. I have learned this the hard way.

It's pointless trying to find a power draw if the battery is knackered. Test the battery and see how much charge it is holding. What's the cranking amps? If battery is still in good condition then it's car issue otherwise if battery isn't holding its full capacity then it's your usage that's the issue.
The OP has said that he's on a second new battery and they discharge after 4 days, excluding the unlikely possibility it's the new-new battery that can only be down to a parasitic drain.
Unless you have arctic weather the battery should be good for several weeks and re-charge quickly even on a short run. I have left mine for four or five weeks without issue, although I tend to stick it on a CTEK for its winter hibernation.
As a matter of interest smart battery conditioners can, over a period of weeks restore a lead/acid battery cell suffering with sulfated plates, the very low current 'float' action reverses the deposits. My original BMW battery went on a CTEK every winter and lasted about 15 years!
However, cell plates distorted by conventional chargers or jump starting cannot be restored.

Given what he's said I'm sure that the OP is on the right track looking for the parasitic drain.
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E85 LONG RUNNING BATTERY DRAIN - NEED HELP IN FINDING A COMPANY WHO CAN IDENTIFY PROBLEM

Post by Ewazix » Wed May 11, 2022 8:55 am

SonnyA85 wrote: Wed May 11, 2022 12:22 am How often do you drive the car? How many miles does it do per year?

You say this is a low mileage only done 40k miles.

I think you are the problem not the car. You aren't driving it enough.

When you aren't driving it. How often do you charge it? Is it once a month? Be honest how long have you let it go between charges?

Once a battery goes below 12v it's knackered. It doesn't matter if you charge it up again it's lost a lot of its power. Then every time it goes below 12v it will get worse and worse til eventually it won't start the car at all.

I charge my car every weekend. And I mean every weekend all the way to full. I literally just charged it a few days ago and it was at 80% but still took majority of the day to charge. It's a brand new battery only just replaced a month or two back and I bought top of the line Bosch because I also don't drive much so wanted biggest battery so it doesn't go flat after a couple of days. This is my third battery for the car in 6 years. I have learned this the hard way.

It's pointless trying to find a power draw if the battery is knackered. Test the battery and see how much charge it is holding. What's the cranking amps? If battery is still in good condition then it's car issue otherwise if battery isn't holding its full capacity then it's your usage that's the issue.
The OP has said that he's on a second new battery and they discharge after 4 days, excluding the unlikely possibility it's the new-new battery that can only be down to a parasitic drain.
Unless you have arctic weather the battery should be good for several weeks and re-charge quickly even on a short run. I have left mine for four or five weeks without issue, although I tend to stick it on a CTEK for its winter hibernation.
As a matter of interest smart battery conditioners can, over a period of weeks restore a lead/acid battery cell suffering with sulfated plates, the very low current 'float' action reverses the deposits. My original BMW battery went on a CTEK every winter and lasted about 15 years!
However, cell plates distorted by conventional chargers or jump starting cannot be restored.

Given what he's said the OP is on the right track looking for the parasitic drain.
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E85 LONG RUNNING BATTERY DRAIN - NEED HELP IN FINDING A COMPANY WHO CAN IDENTIFY PROBLEM

Post by longleydel » Wed May 11, 2022 9:11 am

Thanks SonnyA85 and Ewazix for your comments. I bought the car privately last July and have probably done about 1,100 since. I try to give the car a good run at (up to an hour) every week, but this hasn't always happened, especially during the winter. Iv'e bought 2 Bosch (680 CCA) batteries so far, the last around 6 weeks ago.

I use a Topdon BT100 battery tester to check battery health 3 or 4 times a week. When the battery shows low voltage/CCA , or to the point where the engine fails to turn over (usually 4-5 days) I use a NOCO Genius 5 (5 amp) smart charger to recharge it. I have avoided jump starting the second battery, as I believe this helped the first one to die.

An auto electrician carried out numerous tests last summer and concluded like you that the car wasn't being used sufficiently. I then used it more, but the drain still persisted. The same auto electrician carried out further testing more recently and thought we had identified the drain to either the climate control unit or the blower resistor (hedgehog). All relevant fuses were removed, but after 3 days the battery had flattened (down to around 8.5v). The battery has been recharged out of the car. I haven't put the battery back yet, but it has held a full charge now for several days. Presumably, the battery would loose its charge out of the car if it was no longer servicable.

Ewazix, you mention changing the hedgehog. Can you still purchase these new? I believe the original part no. for these is 64 11 6 920 365 (fits all models of E85/E86), but ( I read somewhere) was superceeded by part no. 64 11 5A 3F3B9. Unfortunately, I cannot track down any new ones on line with these part numbers. There are ones for for the E46 avaiable new, but unclear if the same blower was fitted to Z4's (like quite a few other parts from the E46).

Thanks again for your helpful comments.

Derek

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E85 LONG RUNNING BATTERY DRAIN - NEED HELP IN FINDING A COMPANY WHO CAN IDENTIFY PROBLEM

Post by longleydel » Wed May 11, 2022 9:15 am

I should add that, I do not leave the car on long term trickle charge, but sufficiently enough to recharge the battery.

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E85 LONG RUNNING BATTERY DRAIN - NEED HELP IN FINDING A COMPANY WHO CAN IDENTIFY PROBLEM

Post by SonnyA85 » Wed May 11, 2022 9:21 am

Ewazix wrote: Wed May 11, 2022 8:55 am
SonnyA85 wrote: Wed May 11, 2022 12:22 am How often do you drive the car? How many miles does it do per year?

You say this is a low mileage only done 40k miles.

I think you are the problem not the car. You aren't driving it enough.

When you aren't driving it. How often do you charge it? Is it once a month? Be honest how long have you let it go between charges?

Once a battery goes below 12v it's knackered. It doesn't matter if you charge it up again it's lost a lot of its power. Then every time it goes below 12v it will get worse and worse til eventually it won't start the car at all.

I charge my car every weekend. And I mean every weekend all the way to full. I literally just charged it a few days ago and it was at 80% but still took majority of the day to charge. It's a brand new battery only just replaced a month or two back and I bought top of the line Bosch because I also don't drive much so wanted biggest battery so it doesn't go flat after a couple of days. This is my third battery for the car in 6 years. I have learned this the hard way.

It's pointless trying to find a power draw if the battery is knackered. Test the battery and see how much charge it is holding. What's the cranking amps? If battery is still in good condition then it's car issue otherwise if battery isn't holding its full capacity then it's your usage that's the issue.
The OP has said that he's on a second new battery and they discharge after 4 days, excluding the unlikely possibility it's the new-new battery that can only be down to a parasitic drain.
Unless you have arctic weather the battery should be good for several weeks and re-charge quickly even on a short run. I have left mine for four or five weeks without issue, although I tend to stick it on a CTEK for its winter hibernation.
As a matter of interest smart battery conditioners can, over a period of weeks restore a lead/acid battery cell suffering with sulfated plates, the very low current 'float' action reverses the deposits. My original BMW battery went on a CTEK every winter and lasted about 15 years!
However, cell plates distorted by conventional chargers or jump starting cannot be restored.

Given what he's said the OP is on the right track looking for the parasitic drain.
It's possible the new battery had been sitting on the shelf a while. He has then plugged it into his car and then not used it much. Forgot to charge it for a few weeks and now it's knackered. It's a possibility. I know this from experience. The charger I use is a ring smart charger with a lot more functions than the one he has. Because my neighbor had the same issue and I had to use my charger to show him the new true capacity of his battery even though his charger was saying it was fully charged. It was holding 10% of the original capacity. He needs to measure the capacity of his new battery and see if it's the battery or not. It's simple to then exclude that from the list of possibilities.

Mine has a reconditioning/repair function. I tried this several times on my old battery that I got a few years back and nothing. It would charge but capacity was gone. Showed the correct voltage but not enough crank in it to start the car.

I'm in his same shoes. It's why I now charge mine every weekend. Doing it once in a blue moon wasn't enough to save the battery. Every time it gets discharged it's killing his battery he's saying this has happened several times on his new battery so it's possible if he's got a parasitic drain the new battery has now been severely limited because of it.

Also when I got a new battery I tested it's capacity and it was higher than on the spec sheet. Spec said 780ah and I'm sure it was 820ah if I recall correctly upon testing. I would do this test when fully charged and see what happens.

He said he's already pulled all the fuses. I'm guessing the battery is knackered from the several times it's been drained and re charged. It's a possibility.

Get it on a decent charger and check how much capacity is left in it. The voltage it reads doesn't tell you anything you need to know how much ah it holds when full.

If the new battery is okay then I would look elsewhere for issues. I knackered a new battery by being a low miler. Top of the range Bosch it was too. I do have a £600 aftermarket amp in the boot so my car is power hungry. It's why I top it up every week. It's a pain but has to be done. I left it for 2 weeks and it had dropped to 80%. So it's losing 10% a week just sitting on the drive. If it goes below 60% you are in trouble as that's what impacts long term life.

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