T6.1 12v cab sockets with factory aux battery

[EAN]

Have looked at previous threads and some seem to conflict with what I’m finding.
2023 T6.1 Hillside Birchover Classic campervan; uses standard VW factory fitted aux battery fitted under passenger seat.
I’ve just measured the voltage on both the upper and lower cab 12v sockets both with the EHU mains aux battery charger on and off.
Am getting the same voltage readings from both, which leads me to believe that they are both connected to the aux battery, whereas some threads state the lower one is connected to the starter battery.
Assume that there has been a change at some point?
I was intending to conveniently plug into the lower socket to trickle charge my starter battery, as per some other threads but it isn’t going to work for me.
Will have to fit a quick charge connector between the starter battery positive and chassis negative under the bonnet, or perhaps maybe pick up the starter battery feed under the passenger seat (before the split charge relay - which also needs to be swapped out for a DC-DC at some point)

 

[Dellmassive]

Got a few pics to add context

 

[EAN]

Got a few pics to add context

@Dellmassive , sure, these pics from my phone show what’s under the passenger seat.
Don‘t wish to take the seat off at the moment as van is about to be used.
My understanding is it’s a factory fit aux battery.

 

[Captain Quick]

Have looked at previous threads and some seem to conflict with what I’m finding.
2023 T6.1 Hillside Birchover Classic campervan; uses standard VW factory fitted aux battery fitted under passenger seat.
I’ve just measured the voltage on both the upper and lower cab 12v sockets both with the EHU mains aux battery charger on and off.
Am getting the same voltage readings from both, which leads me to believe that they are both connected to the aux battery, whereas some threads state the lower one is connected to the starter battery.
Assume that there has been a change at some point?
I was intending to conveniently plug into the lower socket to trickle charge my starter battery, as per some other threads but it isn’t going to work for me.
Will have to fit a quick charge connector between the starter battery positive and chassis negative under the bonnet, or perhaps maybe pick up the starter battery feed under the passenger seat (before the split charge relay - which also needs to be swapped out for a DC-DC at some point)

Ean, did you manage to find somewhere convenient within the interior space to connect a battery conditioner to keep your starter battery charged? I’ve just taken delivery of my new T6.1 Hillside Birchover and encountered exactly the same issue as you with both 12v sockets at the front connected to the secondary leisure battery (the voltage at both the upper and lower sockets measured 13.8V when on hook up whereas the starter battery voltage was 12.6V).

I was planning connect the van to shore power via a single EHU cable and just plug a CTEK conditioner into the 13A socket in the habitation area so I’m also looking for an alternative connection point inside until I can get round to installing a Renogy DC-DC charger with MPPT and a PV panel.

 

[EAN]

Ean, did you manage to find somewhere convenient within the interior space to connect a battery conditioner to keep your starter battery charged? I’ve just taken delivery of my new T6.1 Hillside Birchover and encountered exactly the same issue as you with both 12v sockets at the front connected to the secondary leisure battery (the voltage at both the upper and lower sockets measured 13.8V when on hook up whereas the starter battery voltage was 12.6V).

I was planning connect the van to shore power via a single EHU cable and just plug a CTEK conditioner into the 13A socket in the habitation area so I’m also looking for an alternative connection point inside until I can get round to installing a Renogy DC-DC charger with MPPT and a PV panel.

Short answer No, I’m finalising how I’m going to go over to Lithium (to fit this Winter whilst we aren‘t camping).
Haven’t had any problem at all with Starter Battery though; van can get left for a couple of weeks between trips and starts without Issue. Current plan is to just add a connector under the seat as part of the DC-DC wiring to come.

 

[Captain Quick]

Short answer No, I’m finalising how I’m going to go over to Lithium (to fit this Winter whilst we aren‘t camping).
Haven’t had any problem at all with Starter Battery though; van can get left for a couple of weeks between trips and starts without Issue. Current plan is to just add a connector under the seat as part of the DC-DC wiring to come.

Thanks Ean. I think that’s the direction in which I’m headed. I’ve an extension lead for the CTEK MXS 5.0 that has eye terminals at one end which I’ll hopefully be able to connect to the starter battery circuit via the split charge relay connections.

 

[Captain Quick]

Following on from my previous post, I thought I’d found an easier way of hooking up my CTEK battery conditioner to keep the starter battery charged up. My van (built in March this year) has a factory fitted tow bar installed along with a 13 pin Euro connector socket. As well as a chassis ground (-ve), this socket should in theory at least, provide a direct connection (+ve) to the starter battery and avoid me having to break into the wiring under the passenger seat. This arrangement would certainly be very convenient as it would mean running just a short length of cable from the CTEK charger which could be located in the garage. A cause for celebration you might be thinking. Well no actually.

I tested the socket and sadly there is 0V showing between Pin 9 (+ve) of the socket and Pin 13 (chassis -ve) regardless of whether the vehicle is locked or open. As wiring diagrams always show Pin 9 as being a direct connection to the battery and not an ignition fed supply, it seems there’s a control unit that’s disconnecting the battery feed to the socket when the tow hitch isn’t deployed. I’m wondering now if the tow hitch (which is removable) needs to be in place to enable the power supply at the connector or there’s some kind of interlock whereby inserting a plug powers up the socket. It’s never straightforward with these vans is it?

 

[EAN]

@Captain Quick A quick search for towing socket on here confirms it’s never straight forward and the power, if you finally get it, might possibly be coming from the aux battery anyway.

 

[Captain Quick]

@Captain Quick A quick search for towing socket on here confirms it’s never straight forward and the power, if you finally get it, might possibly be coming from the aux battery anyway.

Looks like it‘s back to the original plan to pick up a connection under the passenger seat as the tow connector and 12v sockets at the front clearly won’t work.

 

[roadtripper]

FYI did some testing on mine for similar reasons and Pin 9/13 behave as expected:

T6.1 OEM Towing Socket behaviour

So today I have been tinkering with my towing socket and thought this might be useful info in a post for others. My van is a MY21 T6.1 Caravelle with full towing electrics from factory. (Edited to add mine is a single battery system) This is my experimental 13 pin plug. There are 4 grain of...

www.t6forum.com

From reading other threads I think that this "feature" is one of the things you can flip on or off via VCDS - so behaviour varies but that does mean you might be able to enable it.