Parasitic Drain. Pain. Again?

[BigGreenThing]

I know there are plenty of other posts on this subject but before going down the route of parasitic drain, I just want to set the scene and consider options.

- I bought a new Volvo battery in May 2022.
- Just in Volvo main dealer garage now and they say the battery is at "30%".
- Volvo say battery is "too old" to perform a BCM "reset". Is this true?

Stated: "Battery low SOC, requires charging and retest, possible quiescent drain on system if battery drains again" and wanted £96 and keep car overnight to recharge.

If drain continued then another test (more money). Battery only cost about £120.

There are two additional "peripherals" added to the vehicle. One is a DTUK tuning box (disconnected and box removed and I've never used it. Never will).

The other is a an Auto-vox mirror dash cam (front and rear dashcam which I gave a low down on experience of fitting here: https://www.volvoforums.org.uk/showt...=BigGreenThing)

The technician said there are a couple of "additional wires" into battery - I suspect the tuning box!

The dashcam "off" mechanism/ trigger is governed by the footwell courtesy light fuse. so when the footwell lights go off (when you leave/lock car) it switches off the dashcam power too (in theory!).

My 4 questions are:

1) has anybody experienced either of the above two points draining battery?
2) The alternator works fine. Volvo have confirmed...but can an alternator recharge a 70% drained battery, or do I need to buy a battery charger?
3) I don't have the opportunity to charge the battery "in situ" as car sits outside. Is it OK to disconnect and remove the battery and charge it, and then out it back in again?
4) if yes to #3...should I perform a BCM reset?

Oh - as an aside, and in spite of the car passing MOT 5 days ago....Volvo gave me work for £1,679!!! . Included:


- Both rear brake pipe joiners heavily corroded, req replacement + brake fluid bleeding
- Exhaust system corroded, central hanger very weak, advise new exhaust system (catback)
- Minor play in NS inner track rod ball joint, advise replacement then alignment
- Rear anti roll bar drop link bushes deteriorated, advise replacement


Other than that - the car seems fine! Lol!

[FreshAir]

I charge our batteries in the vehicle on the drive. Use a Ctek charger, put a plastic box over it. Great bit of kit. Advise getting the 2m extension cable as will have no issue with reach to the battery + grounding point then.

If you charge the battery off the vehicle then a BCM reset would be needed as it will have no update from the charge you do IMO.

If you disconnect power to the dashcam, you can rule that out without question or doubt then.

[SnineT]

Unless you take it in for a proper inspection which they will probably say "yes its got a drain sir but we don't know where from" you'll need to do one fuse at a time, actually quicker if you do blocks of five and once the fault shows up in the five do them one at a time, if the fuses doesn't nail it it's one relay at a time and then after that it's how long is the string.


Some simple checks if you've not done them would be all of the door shut sensors although how you'd tell once the dash goes black I don't know, have someone shut you in in the dark so you can make sure the boot light is going off.

I think a lot of the time when this crops up and isn't an earth lead etc it's the car has been knocked in the past and the repair guy misses something out putting it back together which then becomes a needle in a haystack.


I just noticed you have the cam, this is where I'd start as they do drain quite fast if hard wired to a perm live, it's possible it's also open circuit inside somewhere even though it's still working ok so never really going to sleep, if you're letting it run all night as scrote defence that will also knock the battery out, I think your best bet is to bite the bullet and start with a new battery tbh, then if it drains again at least you know it's not the battery, might as well have a new one vs the diagnostic charge.

[robertjary]

I'm surprised that the exhaust needs changing. I've taken 2 x V70s each past 200,000 miles on the original exhausts. Both were D5 autos.

[BigGreenThing]

Originally Posted by robertjary

I'm surprised that the exhaust needs changing. I've taken 2 x V70s each past 200,000 miles on the original exhausts. Both were D5 autos.

It's a bit random isn't it.

To be fair, for some reason, there does appear to be a fair amount of surface rust underneath (prior to my ownership!)

Car doesn't do short journeys - so issues related to moisture shouldn't be there. Car has done 151,200 miles.

In Sept '21 - same garage said exhaust was in "good condition", no mention of it in Jan '22...come Jan '23 - different story!

It's the post-CAT bit (at the joint...it's corroded)...and the x3 exhaust supports at the rear have perished . Other than that the exhaust is fine! Doesn't leak.

[BigGreenThing]

Originally Posted by SnineT

Unless you take it in for a proper inspection which they will probably say "yes its got a drain sir but we don't know where from" you'll need to do one fuse at a time, actually quicker if you do blocks of five and once the fault shows up in the five do them one at a time, if the fuses doesn't nail it it's one relay at a time and then after that it's how long is the string.


Some simple checks if you've not done them would be all of the door shut sensors although how you'd tell once the dash goes black I don't know, have someone shut you in in the dark so you can make sure the boot light is going off.

I think a lot of the time when this crops up and isn't an earth lead etc it's the car has been knocked in the past and the repair guy misses something out putting it back together which then becomes a needle in a haystack.


I just noticed you have the cam, this is where I'd start as they do drain quite fast if hard wired to a perm live, it's possible it's also open circuit inside somewhere even though it's still working ok so never really going to sleep, if you're letting it run all night as scrote defence that will also knock the battery out, I think your best bet is to bite the bullet and start with a new battery tbh, then if it drains again at least you know it's not the battery, might as well have a new one vs the diagnostic charge.

I've started at the cam. Power supply is piggybacked of fthe internal "courtesy footwell" light. So when the footwell lights go out...in theory - the cam power should cease also. I've disconnected the power connection at the actual unit for now. Never had the scrote defence on due to potential for drain. Back in the Summer I had put up a post about a "small green light" in the internal rear passenger cluster. That doesn't go out. That must drain battery if it stays on maybe?

I've acquired Vida - so presuming I might check battery status there...

[seanc]

Originally Posted by BigGreenThing

I've started at the cam. Power supply is piggybacked of fthe internal "courtesy footwell" light. So when the footwell lights go out...in theory - the cam power should cease also. I've disconnected the power connection at the actual unit for now. Never had the scrote defence on due to potential for drain. Back in the Summer I had put up a post about a "small green light" in the internal rear passenger cluster. That doesn't go out. That must drain battery if it stays on maybe?

I've acquired Vida - so presuming I might check battery status there...

You could consider changing to piggyback from the 12v cig lighter socket via the fusebox - that switches on/off with unlock/lock of the car, position 2 and engine on - done that in 2 cars with no issue.

[BigGreenThing]

Originally Posted by seanc

You could consider changing to piggyback from the 12v cig lighter socket via the fusebox - that switches on/off with unlock/lock of the car, position 2 and engine on - done that in 2 cars with no issue.

Thanks seanc! I don’t know why I hadn’t thought of that originally 😳! For now. I’ve just disconnected the cam unit from the cable, to see what happens for a few days (or weeks maybe). Car starts fine. New Volvo battery in May 2022. Just a little inconvenient that the radio/stereo shuts down after a min or two when engine isn’t running.

[SnineT]

Originally Posted by BigGreenThing

I've started at the cam. Power supply is piggybacked of fthe internal "courtesy footwell" light. So when the footwell lights go out...in theory - the cam power should cease also. I've disconnected the power connection at the actual unit for now. Never had the scrote defence on due to potential for drain. Back in the Summer I had put up a post about a "small green light" in the internal rear passenger cluster. That doesn't go out. That must drain battery if it stays on maybe?

I've acquired Vida - so presuming I might check battery status there...

Leave it disconnected for however long it normally takes for the drain to stop the car, if it's still doing it it's not the cam and you can move on to the next suspect.

[GrahamBrown1]

Did you ever get to the bottom of this, I fear our XC70 may have a drain but it has zero aftermarket accessories installed.