T6 low battery after only a couple of days

KenA

Member
Hi, I've been having various problems with my starter battery over the past year and am not sure what to do next.

The 2016 van was converted and a VSR was installed by the chap who did the conversion, which I've come to realise isn't suitable for a van with a Euro 6 engine.

I replaced the VSR with a Victron B2B charger and also had the starter battery replaced, but despite this, my van is still showing as having low battery after sitting on the driveway for a couple of days.

The start/stop function isn't working either and shows an error message when I turn the ignition.

I'm aware that the leisure battery also probably needs replacing, but this shouldn't have any effect on the starter battery.

I'm not sure what else I can do, as clearly something is a miss and my local garage(s) can't seem to find the problem.
 
If it’s showing a start stop error then the van must be aware of an issue
A fault scan should give you some direction to tracking down the problem or potential problem
 
Not necessarily a battery issue there's quite a few things that can upset stop-start as Pauly said get it scanned buddy
 
What's your driving style?.

Daily driver?

Short trips?

How much is the van used over a week?

Short trips never charge the battery back up enough.
 
Do you have anything wired directly to the starter battery negative terminal? ( like the DC-DC converter) it should be wired to the chassis otherwise the VW shunt keeping track of the starter battery charge wouldn’t be measuring correctly.

simon
 
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I've had it scanned by a local mechanic, but he wasn't able to anything with it. My driving is a mixture of short journeys around town and a few longer ones, but I never had an issue like this with my old T5.
 
To be fair the T5 didn't have some of the tech the T6 does. I would try and check a few of the things some of the guys have previously posted especially what @Sim60 suggested as of the van's battery module 'thinks' there's a problem stop-start it just won't work even though everything may be fine.

On the Neg terminal there's a little block that is part of the battery regulation system of the b2b unit is connect directed directly to this and not the chassis it blind sides the regulation system and it sees it as a problem.

Probably not the best explanation. It hopefully it helps.
 
I would check that the Victron B2B is wired for charging only on ignition live, if not and its charging all the time then your starter battery will suffer :)
Otherwise its just a case of finding a parasitic draw - we had a similar problem with our Scout-van, took a year to find that under the ply-lining, a light was switched on...
 
Do you have anything other than the vehicle earth lead connected to the Negative post on your battery? There should only be that one lead. When I got ours converted they ( following the instructions) fitted the Sterling B2B negative directly to the Negative post along with maybe one other and I noticed on my battery monitor app the starter battery didnt get much charge. I moved them to an independent earth and all seems fine now.
 
I appreciate that it is not completely clear, but here's a photo of the negative terminal. I can't see anything else connected to it...


IMG_20211005_113216.jpg
 
Are you saying the garage did a scan and found no error codes or did they just go "electrics? Dunno mate."
If the stop/start isn't working there will probably be an error code for that and there may be other codes that may help pinpoint this battery issue so I'd suggest getting the van scanned or even better buy OBD11 and scan it yourself. OBD11 is a great tool for VAG vehicles.
 
Are you saying the garage did a scan and found no error codes or did they just go "electrics? Dunno mate."
If the stop/start isn't working there will probably be an error code for that and there may be other codes that may help pinpoint this battery issue so I'd suggest getting the van scanned or even better buy OBD11 and scan it yourself. OBD11 is a great tool for VAG vehicles.
The local garage did plug it in and spent a while running a scan, but then at the end, suggested that I go to my local VW dealer, which is 60 miles away.

Here's the scan relating to the start/stop issue: IMG_20210923_163613.jpg
 
What's all the yellow gunk around the terminal and on the battery monitor?
I'd remove that neg terminal and clean that with some emery cloth. Then start the van and measure the voltage on the starter battery to make sure it's getting charge. (14+V)
 
What's all the yellow gunk around the terminal and on the battery monitor?
I'd remove that neg terminal and clean that with some emery cloth. Then start the van and measure the voltage on the starter battery to make sure it's getting charge. (14+V)
Thanks, I've no idea, I had the starter battery replaced at a local garage, as I think the old one was shot (perhaps due to the charging issue). Unfortunately, I live somewhere where I've not got many garages to choose from and I'm beginning to think that no one around here knows enough about VW electrics.
 
Did they code the new battery to the van? The van needs to be told it has a new battery.
They claim that they did. I wasn't overly impressed, as they put in a lesser spec battery in the first instance and then only when I noticed, did they replace is with a AGM battery.

I've just put a voltmeter on, whilst driving at the voltage fluctuates between 13.8 and 14 volts, even when braking. I'm sure that it used to be higher, but can't be sure.
 
13-14 volts when driving is within normal range, it can go higher sometimes especially under regenerative braking but all depends on battery charge state etc so hard to be sure

Leisure batt seems low though would expect that to be much higher especially if van is being used you would think whatever split charge relay/DC DC charger is there would be topping it up ?
 
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