Solar Install & Mystery Vehicle Battery Drain

[CrazyDunk]

Firstly, my set up:
90ah agm leisure battery
CTEK dc to dc charger
Victron Ac charger
T6 2019 Highline camper conversion with low mileage of 15k on the clock

Job last week carried out by professional installer:
Upgraded agm leisure battery, now 130ah
Installed solar and connected to CTEK
Tidied an array of cables which were directly connected to the terminals of the old battery (now connected via busbar)
Installed Fiamma awning (not likely related to the following issue though)

Situation:
Collected vehicle on Friday, all appeared well apart from a breaker had tripped in the leisure side (noticed once before in a year and just switched it back, possibly linked to electrical work being done).
Ran the fridge down to temp on EHU Saturday night and then left for an event on Sunday off grid for the day.
Camped up on Sunday evening with EHU connected. Nothing left on in the cab, keys not in ignition etc.
Unplugged EHU Tuesday morning (only on EHU for 2 days at this point). Tried to start the van and everything was dead vehicle side. VW Assist came out and it started from a small power pack thing immediately. The guy said vehicle battery was fine and charging, but his tests showed a mystery power draw of between 1 and 2 amps (but with the odd spike to 8 amps! He could run a full circuit test at the roadside, but he suggested taking it back to the installer (who have confirmed they didn't touch any cables on the vehicle side, but are double checking anyway.

Does anyone have any theories from this? Apologies if its been covered before, I had a look through the posts but could not see this scenario had been mentioned.

 

[Dellmassive]

Post some pics of your setup.

Both batteries, and your ctek etc.

Well start from there.

1/2A is way too large a drain.

But you're starter battery will go flat when camping unless you have a way to charge it.

The ctek only trickles the starter from solar. And only when the LB is full.

 

[CrazyDunk]

Post some pics of your setup.

Both batteries, and your ctek etc.

Well start from there.

1/2A is way too large a drain.

But you're starter battery will go flat when camping unless you have a way to charge it.

The ctek only trickles the starter from solar. And only when the LB is full.

I'll post some pics when I get the van back at the weekend.
Had the van for a year now, and this has never happened before. We upgraded the LB and installed solar as the old LB only lasted a couple of days.
Just cannot figure out what has changed, and the only thing which has changed is the work done last week.

 

[CrazyDunk]

Post some pics of your setup.

Both batteries, and your ctek etc.

Well start from there.

1/2A is way too large a drain.

But you're starter battery will go flat when camping unless you have a way to charge it.

The ctek only trickles the starter from solar. And only when the LB is full.

These are the photos of my setup. Same thing happened today after one night camping off grid. Only thing running was the fridge.
CTEK seems to be working shows when solar is charging LB or VB, and also 14.4v on the LB monitor when engine is running.
Work carried out is in the photos (apart from LB itself as that's under a panel.
The job was to relocate the LB from under the bed next to a gas locker to in the cupboard over the wheel arch. Then to take off all accessory cables connected to LB and reconnect via busbars (as in photos).
Solar installed and cables shown coming down into through the back of cupboard. Solar connected to CTEK.
Victron only comes on when on EHU, but this didn't stop the issue before.
For context the van has been running fine as a daily driver for the past week, no issues. Then when we camp up again the starter battery is drained completely overnight. VW Assist tested the vehicle battery itself the other week and said its fine, all charging as it should do.

 

[Bigsidavies]

You don’t say what van you have, but if it’s a T6 with a smart alternator then the red wire should be connected to a switched ignition feed.
Don’t know if this can cause the problem you’ve got.
An easy way to see if the problem is being caused by the ctek is to pull the fuse between ctek and SB.

 

[CrazyDunk]

You don’t say what van you have, but if it’s a T6 with a smart alternator then the red wire should be connected to a switched ignition feed.
Don’t know if this can cause the problem you’ve got.
An easy way to see if the problem is being caused by the ctek is to pull the fuse between ctek and SB.

It's a 2019 T6, not sure where the fuse is but if it helps there's not been an issue in the year we've owned it until this work was done.

 

[Bigsidavies]

In fact, it’s hard to tell in your pics, but it looks like the thin red wire actually goes through the hole in the unit. I was just thinking that maybe they hadn’t reconnected it if they’ve disconnected the ctek for any reason when carrying out the upgrades.
One way of eliminating the new work as the source of the problem would be to disconnect the only link between the leisure system and SB ie the cable between SB and CTEK. Pulling the fuse in that cable would be the easiest way to do it safely.
I’d think it’s the one in the midi fuse holder in the red cable near the SB shown in your picture.
I’m deffo no expert but that’s where I’d start as a basic process of elimination.

 

[CrazyDunk]

In fact, it’s hard to tell in your pics, but it looks like the thin red wire actually goes through the hole in the unit. I was just thinking that maybe they hadn’t reconnected it if they’ve disconnected the ctek for any reason when carrying out the upgrades.
One way of eliminating the new work as the source of the problem would be to disconnect the only link between the leisure system and SB ie the cable between SB and CTEK. Pulling the fuse in that cable would be the easiest way to do it safely.
I’d think it’s the one in the midi fuse holder in the red cable near the SB shown in your picture.
I’m deffo no expert but that’s where I’d start as a basic process of elimination.

Thank you, I'll take a look tomorrow. Unfortunately a new problem occurred jump starting it. Now the dash is lit up like a Xmas tree and the dials don't move at all, it also stays this way when the key is removed and van locked...... so I'm expecting the battery to go down overnight again!