Underseat electrics for Kombi camper conversion

[robmug]

I have a 2019 T6 Kombi (204 DSG, twin sliders, tailgate etc) that I'm just about to start my second conversion.
My sister had our previous 2015 T5.1, and I'm going to do some things slightly differently this time, the main changes being
1. To put as much as possible under the front seats (T5.1 had double passenger seat so we left that for storage).
2. Larger output inverter (camping kettle)
3. Solar (will allow us to go a little longer when we can't get hookup), some race circuits aren't possible to get close enough to hookup
4. As before, bluetooth control for as much as possible and minimum 'stuff' to wire in/display etc
5. Front seats both on swivels

This is my current thinking, and thank you to Martyn from Travelvolts for his help so far! I'll buy all from Martyn if possible, so some of the links are to other sites and I'll update)

VERSION 1
Under bonnet
Slimline EHU to front grille (Compact EHU Connections | Hookup | Motorhome | Van Connections | UK)
Battery monitor (CTEK 40-149 Vehicle Battery Monitor: Amazon.co.uk: Car & Motorbike)
IP65 Consumer unit (Wylex 3-Module IP65 Insulated Enclosure With Visor)

Under passenger seat
Inverter (Victron 12.1200 Inverter | travelvolts)
Victron IP65 battery charger (only for leisure battery when on hookup) (VICTRON Bluesmart IP65 12/15 | travelvolts)

Under driver's seat
CTEK D250SE DCDC charger (will also have 150w solar panel, so CTEK has MPPT)
130aH battery (EXP+130 AGM battery | travelvolts)
Battery monitor (CTEK 40-149 Vehicle Battery Monitor: Amazon.co.uk: Car & Motorbike)
12v Fuse box (12 way fuse box with negative rail. | travelvolts)
Victron 65a SmartProtect (eg Victron Energy Smart Battery Protect 12/24V 65A - BPR065022000 – Battery Megastore)
Heater pipes for Planar heater

Any thoughts that would make wiring easier - eg that reduce the number or gauge of the cables?

I'd love some photos / ideas for the installation under the seats - in my mind it's a super-neat installation but I need ideas to help me get to that!

Also - tips for placement under the seats would also help
Thanks

 

[robmug]

OK, all ordered from Travelvolts; only change is the consumer unit under the passenger seat, as Martyn thinks it will fit.
Seat swivels have been ordered too, so I'll be having some fun tessellating all this lot under the seats and trying to get a neat install.

 

[Graeme_B]

@robmug Looks like similar to what I want to do with my van although I don't think we can accommodate driver swivel.

 

[JasonW]

Setup under drivers seat with 12-12-30 dc charger



Another matching battery under passenger seat for a total of 200 Ah battery power

Backed up with 250W panel with Photonic Universe MPPT

 

[JasonW]

2500 Watt invertor sits behind drivers seat boxed in with ventilated grills with 240V invertor socket on passenger seat rear kick plate and another on the worktop endpanel

 

[Farnorthsurfer]

If you can stretch to a Lithium battery it’s will worth it. I used the TNPower 100A under the passenger seat and it works really well and is very light. Recharge is super fast with a Renogy DC-DC and 160w Solar.
Details in the build thread in my sig

 

[robmug]

That looks a nice installation. And a nice conversion generally.

 

[robmug]

If you can stretch to a Lithium battery it’s will worth it. I used the TNPower 100A under the passenger seat and it works really well and is very light. Recharge is super fast with a Renogy DC-DC and 160w Solar.
Details in the build thread in my sig

Brilliant thread - I love what you've done.
Great pics of the seat electrics installation, will definitely be a help to me when doing mine.
I really like the low box you've built too down the left hand side of the van. Makes good use of that space which really is lost otherwise.

 

[Farnorthsurfer]

Brilliant thread - I love what you've done.
Great pics of the seat electrics installation, will definitely be a help to me when doing mine.
I really like the low box you've built too down the left hand side of the van. Makes good use of that space which really is lost otherwise.

Thanks, it’s sort of a Reimo copy but my LH unit is quite a bit longer. It does get it the way of your legs when the seat is back and would be uncomfortable for a third passenger but there are only two of us so we wanted the storage space instead.
Lots of good threads about DC-DC chargers and batteries, were a massive help to me.
To get the underseat electrics sorted you may need to rearrange the OEM looms to be out of the way.
Easy enough but I was always reluctant to mess with the original wiring too much.

 

[robmug]

Thanks, it’s sort of a Reimo copy but my LH unit is quite a bit longer. It does get it the way of your legs when the seat is back and would be uncomfortable for a third passenger but there are only two of us so we wanted the storage space instead.
Lots of good threads about DC-DC chargers and batteries, were a massive help to me.
To get the underseat electrics sorted you may need to rearrange the OEM looms to be out of the way.
Easy enough but I was always reluctant to mess with the original wiring too much.

Rearranging OEM looms sounds like something I don't want to do...but may be necessary. I have factory towbar too.

 

[Farnorthsurfer]

With the tow bar you may have the extra big red wire under the passenger seat.
Others have used it to supply the DC-DC but I didn’t because it was more hassle than running my own cable from the van battery. Also you can put the supply fuse where you can get at it without removing the vehicle battery and can put in the right gauge cable for the charger you get.
I cut and shut the big red cable to get it to fit with all the other bits. Beware it is welded terminations but there is miles too much cable in there.

 

[robmug]

The flaw in my current thinking is the Planar heater that's also going to be installed - heater pipe runs through the driver's seat base. Going to have to leave spec for that...
It'll all become easier when I can get time to get outside and take the seats out and see what I've got to work with.

 

[Graeme_B]

@robmug is there a reason for going with battery monitors and not smart shunt?

 

[Farnorthsurfer]

The flaw in my current thinking is the Planar heater that's also going to be installed - heater pipe runs through the driver's seat base. Going to have to leave spec for that...
It'll all become easier when I can get time to get outside and take the seats out and see what I've got to work with.

My Planar Heater duct runs under the drivers seat base alongside the Consumer unit, battery charger and towbar control unit. The battery charger is plugged into a single socket with its own breaker. That way I can remove it easily and use it to charge the van or any other vehicle. I bought a spare Victron cable for the DC plug which is wired to the leisure battery. The charger just sits happily under the seat. Plenty of room if you are careful. Not so much space under the Passenger seat with the battery, fuse box DC-DC and a shit load of cables along with a Smart Shunt. Although I am going to put back the BT battery monitor as the smart shunt doesn’t record the voltage history

 

[robmug]

@robmug is there a reason for going with battery monitors and not smart shunt?

Good question. I'm not really sure. I haven't yet bought the battery monitors as I haven't 100% decided. On the last camper I had a battery gauge inside the van which I'll probably do again, so may not even buy the CTEK monitors. What's your view?
The CTEK and Victron battery chargers are smart enough to not need active management (and both can be bluetooth controlled). So I really only need a battery monitor for when I'm off grid to make sure the battery doesn't discharge too much. The Victron SmartProtect will allow for a level of protection on the 12v side.
On the last camper we did, we could go most of a weekend without the leisure battery flattening; on this van we'll have a slightly larger capacity battery (130ah vs 110ah) and a 150W solar panel so we should be slightly better off (although the larger inverter will increase the draw too).

 

[robmug]

My Planar Heater duct runs under the drivers seat base alongside the Consumer unit, battery charger and towbar control unit. The battery charger is plugged into a single socket with its own breaker. That way I can remove it easily and use it to charge the van or any other vehicle. I bought a spare Victron cable for the DC plug which is wired to the leisure battery. The charger just sits happily under the seat. Plenty of room if you are careful. Not so much space under the Passenger seat with the battery, fuse box DC-DC and a shit load of cables along with a Smart Shunt. Although I am going to put back the BT battery monitor as the smart shunt doesn’t record the voltage history

Thanks - useful info. What's under the passenger seat?

My thinking had changed and was going to be:
Driver's seat
CTEK dcdc charger
Leisure battery
12v fuse box
(Planar ducting)

Passenger seat
Victron mains charger
Consumer unit
Inverter.

Really not sure if I have enough room, but I'll find out when I try!

 

[Farnorthsurfer]

Thanks - useful info. What's under the passenger seat?

My thinking had changed and was going to be:
Driver's seat
CTEK dcdc charger
Leisure battery
12v fuse box
(Planar ducting)

Passenger seat
Victron mains charger
Consumer unit
Inverter.

Really not sure if I have enough room, but I'll find out when I try!

Passenger seat is battery, fuse box and DC-DC unit. Photos in my signature thread link.
I know its not a huge difference but your DC cables can be shorter if the leisure battery and DC-DC are on the left behind the main battery. The heater is often under the floor on the right where short ducts are best. And the 240v cable doesn’t really matter how long it is unlike the 12v cables. Especially with high current charging from modern DC-DC kit.
These are not ‘rules’ in any way but it made sense to me.

 

[Graeme_B]

Good question. I'm not really sure. I haven't yet bought the battery monitors as I haven't 100% decided. On the last camper I had a battery gauge inside the van which I'll probably do again, so may not even buy the CTEK monitors. What's your view?
The CTEK and Victron battery chargers are smart enough to not need active management (and both can be bluetooth controlled). So I really only need a battery monitor for when I'm off grid to make sure the battery doesn't discharge too much. The Victron SmartProtect will allow for a level of protection on the 12v side.
On the last camper we did, we could go most of a weekend without the leisure battery flattening; on this van we'll have a slightly larger capacity battery (130ah vs 110ah) and a 150W solar panel so we should be slightly better off (although the larger inverter will increase the draw too).

Tbh I'm a novice at this and trying to glean as much info and tips from the forum as possible. I'm looking at a very similar set up in terms of my requirements and have the smart shunt on my list rather than battery monitors so was seeing if there is good reason to go with one over the other?

 

[Farnorthsurfer]

The Victron Smartshunt is great for telling you what current the battery is drawing or putting out and can also tell you the vehicle battery voltage.
But it doesn’t record voltage, or any other history unless you leave it running on the app.
A simple Bluetooth voltage monitor will tell you what the battery voltage was doing all day.

 

[JasonW]

BM2's on all my batteries and a wifi dongle with Solar station on the MPPT.....

Its more than adequate for battery monitoring and to check the panel is doing its job.

If you're the geeky type and want to monitor current draws etc, then the smart shunt is probably for you....