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

[longleydel]

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.

Hi, Really appreciate your comments.

I have just tested the battery (680 amp CCA) which I removed from the car (not yet replaced) and fully charged a few days ago. The readings appear good: Health 100%, Charge 98%, 765 CCA, 13.03v, Internal ressitance 3.91 ohms. Compared when I first purchased this new battery the readings were: Health 100%, Charge 98%, 750 CCA, 12.63v, Internal ressitance 4.00 ohms.

Recntly however, the battery had discharged signficantly (while in the car and connected), Health & Charge down to 6% and 0% respoectively, 170CCA, 9.49v and Internal ressitance at 17.48 ohms.

From what you say this 6-week old battery could be past it. But, I'm surprised the apparent health etc on testing appears to have held up after several days from when it was charged.

Derek

[SonnyA85]

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.

Hi, Really appreciate your comments.

I have just tested the battery (680 amp CCA) which I removed from the car (not yet replaced) and fully charged a few days ago. The readings appear good: Health 100%, Charge 98%, 765 CCA, 13.03v, Internal ressitance 3.91 ohms. Compared when I first purchased this new battery the readings were: Health 100%, Charge 98%, 750 CCA, 12.63v, Internal ressitance 4.00 ohms.

Recntly however, the battery had discharged signficantly (while in the car and connected), Health & Charge down to 6% and 0% respoectively, 170CCA, 9.49v and Internal ressitance at 17.48 ohms.

From what you say this 6-week old battery could be past it. But, I'm surprised the apparent health etc on testing appears to have held up after several days from when it was charged.

Derek

Okay the battery looks fine then based on that. Be honest how often do you drive it? It could be the low use and not a parasitic drain. I don't use my car alarm fully fyi. I lock the car using the key not the fob.

Try that for a a few weeks.

Basically when you get out the car. Shut the door. Put key in the door and lock it. Don't hit the button on the fob.

The car is still secured and alarmed just some of the sensors have now been turned off.

It could be the cars security system draining it rapidly. Especially since you have pulled all the plugs already.

But you need to charge it every weekend from now on and see what it's dropped to from one week to the next. Also try and use the thing lol that's even better. I'm in the same boat 9k miles in 6 years. I have to force myself to use it. Summer is here so no excuse.

[longleydel]

Sorry, I thought my last message didn't post. Will look at your latest one now.

Derek

[longleydel]

I try and drive it every week (around an hour), but much less so during winter.

I don't have a garage, but keep the car carefully covered on the drive. But, I'll try locking as you suggest and trickle charge more frequently.

Wind is a big factor as to when I use it, as it can be difficult to remove/replace the cover on a breezy/windy day.

Thanks again for your thoughts.

Derek

[SonnyA85]

I try and drive it every week (around an hour), but much less so during winter.

I don't have a garage, but keep the car carefully covered on the drive. But, I'll try locking as you suggest and trickle charge more frequently.

Wind is a big factor as to when I use it, as it can be difficult to remove/replace the cover on a breezy/windy day.

Thanks again for your thoughts.

Derek

If you find it's draining really fast within a week and drops below 80% from full within a week and when the alarm isn't on full mode then I'd see if someone with a decent scanner can run a test for you.

I have a Carly if you are anywhere near Glasgow I'll be happy to check for issues I'm home most of the time anyways and I can even potentially test your battery using my smart charger and see what it says.

Hope you get it sorted. It could be the alternator if it's not the battery. It's not being charged when driven and you are just depleting the battery more by starting the car and using it.

So I'd Google how to test the alternator and search on here as well and YouTube. That could be the issue as well. Unless your mechanic already tested the alternator.

[longleydel]

If you find it's draining really fast within a week and drops below 80% from full within a week and when the alarm isn't on full mode then I'd see if someone with a decent scanner can run a test for you.

I have a Carly if you are anywhere near Glasgow I'll be happy to check for issues I'm home most of the time anyways and I can even potentially test your battery using my smart charger and see what it says.

Hope you get it sorted. It could be the alternator if it's not the battery. It's not being charged when driven and you are just depleting the battery more by starting the car and using it.

So I'd Google how to test the alternator and search on here as well and YouTube. That could be the issue as well. Unless your mechanic already tested the alternator

Hi, thanks for your message. Its great that the Forum attracts many knowledgeable people willing to help and advise.

Thank you for your kind offer, unfortunately I live in the south east corner of England.

The alternator was tested by the auto electrician last summer and found to be working normally. My battery tester has the facilty to check the alternator and run a ripple test. I did this more recently and everything was normal.

Thanks again.

Derek

[Ewazix]

The FSU hedgehog your tech' suggested might be at fault is listed with the superceded part numbers on realoem.com, lots of aftermarket ones around for sale on the web when searching for the original part no.
https://www.realoem.com/bmw/enUS/partxr ... +6+920+365

[longleydel]

Many thanks for this.

Cheap enough to buy and swap it over, given earlier thoughts that the drain may relate to the blower/climate control unit. I believe a faulty hedgehog can still power up the the climate control even though ignition off/car locked etc.

Think I'll also invest in a multi-meter and test everything fuse by fuse. Online videos on identifying a parasitic drain appear really helpful.

Derek

[Mike6]

Electrical problems are way above my paygrade but going back to basics parasitic drain would presumably mean problems with a circuit that stays live when ignition is switched off. If that is correct then I would hope you could eliminate a number of the cars electrical circuits.
You say you have checked boot light, internal light but with car locked I am not sure how you can be sure bootlight, glovebox light and pull down locker light have all gone out. I would at least start be removing these bulbs as they are all known factors in battery drain.
If you can I would leave car unlocked when parked up at home to eliminate any possibility of drain from alarm, locking mechanism etc.
A further probably unhelpful suggestion is to check all connectors to battery (Goodness know what all those leads are for) and to the starter motor and earths.
Now gone way beyond my comfort zone but good luck in tracking down the problem.

[longleydel]

Thanks for your comments Mike.

Electrical issues don't come easily to me either, but, research on the internet, the Forum and online videos about tracing parasitic drains suggests its not too difficult, just time consuming.

In terms of checking fuses I was going to start with those that remain live once the car is locked (located a useful fuse box diagram on the Forum yesterday showing the cabin fuses).

I have removed the boot light bulb. Oddly, I don't have a glovebox light which is strange given the vehicle is a 3.0 SE (understand where you have a light people leave their phone in the glove box on video to check). I know the pull down locker light is going out as I can just see it doing so when I close the compartment.

The auto electrician seemed to rule out loose battery connectors (which I had already checked) and earths etc.

I think not locking/alarming etc is a good approach in the meantime.

Derek

[SonnyA85]

Definitely lock it buddy. But don't use the fob use the key in the door.

[longleydel]

Point taken, definitely.

[bg1]

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

Could I ask for a brief 'how to' use this Topdon. I don't really understand!?

[longleydel]

Hi, yes no problem. The model I have is the BT100. The user manual is really good. In use the tester is fairly intuitive and after a few uses should become second nature. You can also find some helpful videos on U-Tube.

I tend to use it more for keeping an eye on the battery performance (particularly in view of the intermittant parasitic battery drain I have). Always connect the positive clamp to the battery first and disconnect last. The unit powers up once the nagative clamp is attached to the battery (no internal batteries). The important thing is that as you go through the menu when carrying out the Battery Test is to identify the relevant CCA (Cold Cranking Ameprage) for your battery (should be a label on the battery). Mine is 680 CCA.

This battery test shows the health and charge held in the battery (e.g. a new battery would probably show around 100% and 98% respectively), the level of CCA (often shows more than stated on the battery, but seems this is quite normal), current voltage (a good battery is usually between 12 and 13 volts), and internal resistance measured in ohms (must admit i'm a little unclear about the relevance of this, though the higher the resistance, the less charge in the battery).

One thing I have noted with this test is that if the battery voltage is quite low (around 9.5 and less) the tester will tell you to replace the battery. But, this isn't always the case. I have recharged (using a trickle charger) a battery so indicated and it has been fine.

The tester also measures the CCA capability of the the battery - will tell you if this is functioning normally or not, and another test called a ripple test which I believe is to do with the charging side of things (again a normal, or otherwise reading,) and a separate charging test of the ability of the alternator to recharge the battery.

I hope this helps.

I looked around for some time for an affordable, but fairly good quality tester, before settling on this one from Amazon.

Derek

[SonnyA85]

If you buy a really good battery it will show a higher CCA than on the spec and a higher voltage too. My Bosch did so. I'm on my third battery in 6 years because of my low miles and if you let the battery go below a certain voltage I think 12v too many times it will just get worse and worse. You can get away with it a couple of times but the more drained it is and the longer it sits like that the worse it is.

It's why some folk have batteries last 10-15 years. They have them sitting around 90% full all year round.