Battery drainage issue

[Rothanaa]

Hey guys, I need some advice. The past few months I've had some battery issues which hasn't been resolved.

Battery drain issue timeline below
- Replaced batteries (delkor 912 cca) on the following dates:
5/3
18/3
17/4

- Alternator replaced on the
8/4.

I had an aftermarket head unit (RCD 330 with a canBus adapter installed over 8 months ago).

Any advice would be appreciated as 3 mechanics couldn't figure out the issue. Thanks

[Lucas_R]

This has happened many times previously with the Mk5 generation of Golf/Jetta etc when upgrading the head unit. I believe you need a particular canbus adapter and if you have the wrong one for your car it will continue to drain the battery.

No doubt someone with direct experience will chime in with the correct info you need.

[Rothanaa]

Sweet, thanks. Process of elimination this has to be only thing I can think of. Fingers crossed it gets sorted

[Howie!]

Hi - I feel your pain, I need to do the same for my GTI.

I’m starting with a voltage drop test on each fuse to isolate which circuit is causing the issue.
(I too have an aftermarket stereo but I’ve had the car w stereo for 5yrs and the drainage issue is new).

There are tables around to identify a) which circuit is which and b) how much voltage drop on a fuse of x resistance = current draw.

Power Probe
How to Do a Parasitic Battery Drain Test | AxleAddict

Oh and I had the battery replaced recently and then my mechanic have a look at service. The best I seem to get out of mechanics is an alternator and battery test - ie. I think parasitic drain takes a bit of work to figure out.

Long story short - I think there’s a lot of guessing when it comes to parasitic drain and checking the voltage drop across the fuses sounds like the best way to get answers, or find an auto electrician.

I’ll let you know how I go, & anyone with direct experience please chime in.




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[Lucas_R]

Might be worth having a read here: New stereo draining battery - TDIClub Forums

[CraigTas]

My MK5 Fsi had parasitic battery drain for years. To make it harder it was intermittent. Flat battery sometimes within a week and other times a couple of months with same driving patterns.
Just recently had a problem with window controls on driver side and narrowed it down to the wiring which is near the hinge inside the rubber grommet. The wires were brittle and broken. Known problem apparently. Fixed that and have fixed drainage problem too. Mightn’t be same as your problem but any shorts can manifest in lots of different ways. Good luck

[Transporter]

The best I seem to get out of mechanics is an alternator and battery test - ie. I think parasitic drain takes a bit of work to figure out.

I agree with you and to make the matter worst, most of the time the car owners don’t want to pay for the diagnostic time.

[epidemic]

I recently installed an aftermarket Joying headunit in my MK5. There is a specific instruction regarding cutting a wire if there is no reverse camera in it etc - which i followed. My old MK6 did go through batteries as well with a Joying headunit.

I will be monitoring my battery charge as well. If anything, this new units boots up pretty fast so i can disable the sleep mode and it will just cold boot every time.

[Sendo_VW_multivan_2010]

Hey guys, I need some advice. The past few months I've had some battery issues which hasn't been resolved.

Battery drain issue timeline below
- Replaced batteries (delkor 912 cca) on the following dates:
5/3
18/3
17/4

- Alternator replaced on the
8/4.

I had an aftermarket head unit (RCD 330 with a canBus adapter installed over 8 months ago).

Any advice would be appreciated as 3 mechanics couldn't figure out the issue. Thanks

Did the battery issue start after the head unit installation?
I installed an aftermarket head unit from Hipzo. I found there was a seperate cable outside the can bus connector. If this was connected, and you turned the ignition off and pulled the key out, the head unit would not turn-off. When I disconnect this seperate power cable , and the turned off the ignition, the head unit powered off automatically. Here is the info that came with the unit.
It’s the connection in the image.


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[airsky98]

Hi - I feel your pain, I need to do the same for my GTI.

I’m starting with a voltage drop test on each fuse to isolate which circuit is causing the issue.
(I too have an aftermarket stereo but I’ve had the car w stereo for 5yrs and the drainage issue is new).

There are tables around to identify a) which circuit is which and b) how much voltage drop on a fuse of x resistance = current draw.

Power Probe
How to Do a Parasitic Battery Drain Test | AxleAddict

Oh and I had the battery replaced recently and then my mechanic have a look at service. The best I seem to get out of mechanics is an alternator and battery test - ie. I think parasitic drain takes a bit of work to figure out.

Long story short - I think there’s a lot of guessing when it comes to parasitic drain and checking the voltage drop across the fuses sounds like the best way to get answers, or find an auto electrician.

I’ll let you know how I go, & anyone with direct experience please chime in.




Sent from my iPhone using Tapatalk

I have this battery draining issue whereby if i left the car stationary for more than 3 days, the battery will be flat.
Not too bothered with it till i was sick recently and when i need to go out, the car is dead...

I have used the same method as well
Went to ERWIN to purchased the diagram so that i can know accurately which fuse is linked to which component (maybe the car manual have this info as well but just want to get other diagrams too)

I found that the fuse connected to CECM is draining quite heavily, around 0.9mV across 10A fuse which is a sympton that the canbus is still active when it suppose to go sleep?

In the end, i decided to send to VW for diagnostic. Left it there for a few days and set me back around 120 SGD.
They mentioned that the CECM and can gateway are draining battery. Wanted 2.6K SGD( 2.79K AUD)

In the end, i went to online to purchase the components and it sort of fix the problem as i have a bluetooth voltage monitor which is able to plot the voltage graph. Usually after 24 hours, it will drop to 12v but now it stays around high 12.3v to 12.4v.

Have yet to go for long holiday yet. Can't really conclude it really works or not as the voltage graph seems to show that there's still an unknown component that will wake up once in a while and drain some battery before going back to sleep.

Eventually i purchased clamp type ammeter, i'm determined to catch this buggy soon