Battery drain

[nikster]

Our 2017 204 T6 Caravelle has battery drain issues, it’s been in the garage for a week with various tests and components removed/replaced to find the source but they have given up and said I need to find an electrician that specialises in such things. They thought they had slowed the drain by resetting components such as body module etc but it’s still as bad as before & the battery drains to flat after 2 weeks of no use. It’s a factory fit out van with no mods at all. Diagnostics are observing the van powers up every 30 mins or so when locked and over time this is draining the battery. If anyone has any recommendations for an auto electrician in the Bournemouth area I’d really appreciate it.

 

[Dellmassive]

Post some pics of the Startet battery connections.

And pics of any additional electronics you have had fitted after factory.

How long does it take to run flat?.

Do you have any battery monitors?

 

[Dellmassive]

Battery Monitoring -- How I Done It --

Battery Monitoring -- How I Done It -- Part #1 Battery monitoring is a very important part of your 12v system . . . . whether its just the vans starter battery or your leisure setup keeping an eye on the power in your battery bank will keep you from breaking down and make sure your weekends...

www.t6forum.com

 

[Dellmassive]

A data scan may help.

Have you access to vcds or similar?

 

[nikster]

Post some pics of the Startet battery connections.

And pics of any additional electronics you have had fitted after factory.

How long does it take to run flat?.

Do you have any battery monitors?

Hi it’s a factory fit Caravelle business. This problem started earlier in the year. The only addition we had fitted was towbar electrics which the garage disconnected when running tests. It was fully charged 2 weeks ago when we picked up form the garage, we went on hols & got back yesterday and it was flat again showing 9 volts on plug in volt 12v socket reader. I’ll take some pics of connections and post here.

 

[Dellmassive]

Sure.

The first thing I would do is add a battery monitor to the starter battery.

That will show you the rate in drop of voltage over the two weeks..... And help isolate the drain.

These are very good.

https://amzn.to/47j3pjb

.

 

[nikster]

Thanks

Sure.

The first thing I would do is add a battery monitor to the starter battery.

That will show you the rate in drop of voltage over the two weeks..... And help isolate the drain.

These are very good.

https://amzn.to/47j3pjb

.





View attachment 223955

thanks I’ll do that - the garage were totally perplexed and have good form on diagnosing electrical problems. They pulled all fuses and modules replaced/tested/monitored drain over a week. They found rear air con would power up every 30 mins and reset that hoping that was the fault but not the case. Their kit was still observing power up & drain when van was locked. Never had a vehicle behave like this before.

 

[Dellmassive]

That seems odd.. so the rear AC.

If that was the case did they disconnect it? To see what happens?

You say not the case, so what happened?

You could also take it to a VW van center and ask them to test it.....

They will charge you a diagnostic fee but may be able to identify the issue as a known problem from other vans?

Sound like an interesting issue, and I'm wondering what diagnostic kit they used to determine that the rear AC was powering up?

....

Parasitic drains are normally tested with a clamp meter around the battery power cables over a 12/24hr period to identify any power draws when locked and sleeping.

If the rate it high enough a thermal camera can be used to located the draw.

But from full to flat over two weeks...... Must be a very small or infrequent draw.


How old is the battery?

Has it been tested recently?

Running AGM batteries flat, only a few times will drastically reduce its capacity.

 

[nikster]

That seems odd.. so the rear AC.

If that was the case did they disconnect it? To see what happens?

You say not the case, so what happened?

You could also take it to a VW van center and ask them to test it.....

They will charge you a diagnostic fee but may be able to identify the issue as a known problem from other vans?

Sound like an interesting issue, and I'm wondering what diagnostic kit they used to determine that the rear AC was powering up?

....

Parasitic drains are normally tested with a clamp meter around the battery power cables over a 12/24hr period to identify any power draws when locked and sleeping.

If the rate it high enough a thermal camera can be used to located the draw.

But from full to flat over two weeks...... Must be a very small or infrequent draw.


How old is the battery?

Has it been tested recently?

Running AGM batteries flat, only a few times will drastically reduce its capacity.

Yes they disconnected & noticed over the test period draw went down but still happening somewhere, they then went thru all fuses and modules one by one over the week. they thought that the aircon reset would give me a month without having to charge but here we are 2 weeks later and N/A. I did take the van to VW in Southmpton first - they ran tests for 24hrs and found nothing and said battery was fine - which lead me to the garage I've just used. The battery i presume is the original fitted. I've attached pics of battery and also the report they generated which details their work if thats helpful

 

[Dundee_Kev]

Get the battery retested, I would be very surprised if it is fit for purpose at that age as it looks original. Not all battery testers give equal results, so a good idea to get it tested from another source. If you have a voltmeter and charger, charge the battery and leave it disconnected. Now monitor the voltage over the next day of two and report back. If the battery is very good, I'd expect it to maintain 12.7 volts easily. If it's weak you'll find it dropping to 12.4 volts quite quickly

Also get the earth's moved to the body so as not to confuse battery monitor.

And like @Dellmassive says, get yourself the BM2 battery monitor. Worth its weight in gold!

 

[roadtripper]

I'd definitely test for drain with those 2 direct grounds (I suspect towbar electrics?) disconnected and long term move them to the nearby bolt on the inner wing.

 

[nikster]

I'd definitely test for drain with those 2 direct grounds (I suspect towbar electrics?) disconnected and long term move them to the nearby bolt on the inner wing.

Yes towbar electrics & thanks I'll do that

 

[Dellmassive]

These need moving from the neg post to the chassis.

The light brackets bolt works well.

They are bypassing the power monitor on the battery.

 

[Dellmassive]

That battery looks like the original.

They are rated 3-5years.

You may get longer if it's looked after.

I'd look at replacing the starter battery as well.

It's defo a cheaper option.


.




.

 

[FairyCakes230]

Posting both in sympathy but also in the hope it supports your initial findings. I have a very similar issue in what is probably the same van, a 2019 factory standard Caravelle T6 204 that I bought this year. Twice conked out with no electrics, no battery warning, both times recovered by RAC. First RAC engineer said there was an aftermarket connection to the battery but not possible to find what that was. Second RAC engineer suggested might have had water damage to the ECU. VW dealer under warranty tested battery and said it and the ECU were fine, but did nothing else to try and work out what was wrong. I have since been charging the battery with a mains charger and have just bought a multimeter to try and monitor the battery’s charge. Plan is to add a leisure battery for peace of mind when out for the day, and get the fitters to sort out the extra connection to the main batter which they reckon is most likely the Westphalia tow bar. They said it might be stopping the car going to sleep, hence the drain.

 

[Dellmassive]

Posting both in sympathy but also in the hope it supports your initial findings. I have a very similar issue in what is probably the same van, a 2019 factory standard Caravelle T6 204 that I bought this year. Twice conked out with no electrics, no battery warning, both times recovered by RAC. First RAC engineer said there was an aftermarket connection to the battery but not possible to find what that was. Second RAC engineer suggested might have had water damage to the ECU. VW dealer under warranty tested battery and said it and the ECU were fine, but did nothing else to try and work out what was wrong. I have since been charging the battery with a mains charger and have just bought a multimeter to try and monitor the battery’s charge. Plan is to add a leisure battery for peace of mind when out for the day, and get the fitters to sort out the extra connection to the main batter which they reckon is most likely the Westphalia tow bar. They said it might be stopping the car going to sleep, hence the drain.

I think you need to get a bm2 battery monitor as well.

See above.

Leave it for a week then post the voltage plots.

 

[nikster]

Posting both in sympathy but also in the hope it supports your initial findings. I have a very similar issue in what is probably the same van, a 2019 factory standard Caravelle T6 204 that I bought this year. Twice conked out with no electrics, no battery warning, both times recovered by RAC. First RAC engineer said there was an aftermarket connection to the battery but not possible to find what that was. Second RAC engineer suggested might have had water damage to the ECU. VW dealer under warranty tested battery and said it and the ECU were fine, but did nothing else to try and work out what was wrong. I have since been charging the battery with a mains charger and have just bought a multimeter to try and monitor the battery’s charge. Plan is to add a leisure battery for peace of mind when out for the day, and get the fitters to sort out the extra connection to the main batter which they reckon is most likely the Westphalia tow bar. They said it might be stopping the car going to sleep, hence the drain.

It does sound like we’ve been on a similar unwelcome journey & also have a westfalia tow bar fitted! I’ve ordered the bm2 and have had a new battery fitted today - hats off to the RAC. I’ve moved the tow bar ground to the headlight bolts as also suggested. Will report back @Dellmassive readings when I’ve got it wired in and bit of time has passed to get some decent reading history

 

[nikster]

I think you need to get a bm2 battery monitor as well.

See above.

Leave it for a week then post the voltage plots.

Dell do you wire pos and neg to the battery directly or just pos and ground elsewhere?

 

[roadtripper]

Dell do you wire pos and neg to the battery directly or just pos and ground elsewhere?

The draw is low enough it's possible to wire directly, and there is some argument this gives the best chance of an accurate voltage reading.

I would however try and add a fuse to the wiring, having seen the inside of a BM2 I'm not really comfortable at the separation as per my post here:

What Have You Done To Your Van Today?

I've had / got stud and nut kits on other cars, makes wheel changing easier.. and adding spacers less hassle if needs be. Thanks for that…. I like’s it! :cool:

www.t6forum.com

 

[Dellmassive]

Dell do you wire pos and neg to the battery directly or just pos and ground elsewhere?

The bm2 is ok direct across the battery as the power draw is very low.

Assuming the van is a daily driver.

If not then just move the neg of the bm2 to the chassis.