[Guide] DC-DC Charger (for leisure battery) -- How I Done It --

[jgm0]

Thanks for the very useful documentation, wondering if its at all possible to have a setup like this but add swivel seat on the double passenger?

 

[kiidrockk]

I have all the lights flashing on smartpass 120s. D250s works fine. This is my wireing diagramm.
Is it correct?
How to you reset smartpass 120s

 

[Snakelimit]

Part2 added, part3 to come . . . . . . .

Part3 is more about the install,

once you have decided on what unit you want to go for, its time to get it fitted.

Now even though i have the BCDC1240 which has built in solar MTTP i chose to go with a seperate Victron MPPT and just run them side by side.

Now you have a few options: If you have the factory fitted leisure battery or not?

If you have the Factory fitted kit then VW will have done all the hard work for you and run all the cables, fitted fuses etc . . . the even give you a nice ignition/engine run wire. (which is nice)

Vw fit a SCR like this : (this is under the front seat (double bench in my case)

This needs to be removed and replaced with your shiny new DC-DC charger.

They will also have fitted a second battery for you: again here under the double bench:

Now at this point depending on the Amp rating of your new DC-DC you may be able to just replace the relay with this mod from @travelvolts https://www.travelvolts.net/product-page/plug-and-play-upgrade


View attachment 52401

Which make the install plug-n-play and leaves the original factory setup in place.

If not then you can do as i done and just cut out the factory supply fuse and relay and replace it with your own . . . . i went for MIDI style fuse holders and crimps.

I also chose to add some battery monitors at the same time . . . at this point it was a couple of BM2 battery monitors . . . . like these :

.

Because i had the factory wiring, the link to the starter battery was already in place and fused,
the link to the AUX battery was there and fused,
The ignition feed wire was already there,
all i needed to add was a new ground cable for the DC-DC.

i used velcro to stick the DC-DC to the seat basr, and made all the connections with MIDI fuses and crimps.

I also decided to fit a new fusebox to the AUX battery at the same time . . .

once complete i used the BM2 battery monitor to keep an eye on the performsnce of the new DC-DC charger . . . as we can see here it works perfectly (on the EFB+ AUX battery)

it also worked great as a jumpstart for a dead AGM battery when camping charging the battery at the full 40Amps with the engine running. see here > Mobile Solar Panels ? . . . - How I Did It -

and some final battery testing . . .

.


.

more in part 4

Hi Dell question as I got similar set up with factory battery and hoping to reuse as you mention in post. Removing relay etc. I assume the original wiring its ok for victron Orion xs as you already swapped few different dc dc chargers there and newer mentioned about wires, my question its what if I need move charger away from seat as inverter too big and need get under bad next to wheel arch. Does that wire would be still ok or should I fit new one bigger size? It says 16mm under 5m but no clue how long wire it’s up to seat. And ideas please let me know and thank you, I try learn as much as possible from you posts

 

[TallPaul_S]

Hi Dell question as I got similar set up with factory battery and hoping to reuse as you mention in post. Removing relay etc. I assume the original wiring its ok for victron Orion xs as you already swapped few different dc dc chargers there and newer mentioned about wires, my question its what if I need move charger away from seat as inverter too big and need get under bad next to wheel arch. Does that wire would be still ok or should I fit new one bigger size? It says 16mm under 5m but no clue how long wire it’s up to seat. And ideas please let me know and thank you, I try learn as much as possible from you posts

That's a much longer run and so you'll get more voltage drop, and more heat so I'd personally want to increase the size.

I'm using an Orion XS with the standard factory wiring and it's been perfectly fine, but mine is under the passenger seat.

 

[Snakelimit]

Dang that’s what I did planning to do but with moving all away I might consider run 25mm then. Or might run 16 from seat then test run with thermal camera and heavy load to see if cable getting too hot or it’s ok

 

[Captain Quick]

That's a much longer run and so you'll get more voltage drop, and more heat so I'd personally want to increase the size.

I'm using an Orion XS with the standard factory wiring and it's been perfectly fine, but mine is under the passenger seat.

Same as me. I used as much of the original installation under the passenger seat as I could. I replaced the VW split charge relay with a fabricated box that fitted into the space left and that clipped in using the same attachment method. Inside this box is a midi fuse holder with a 60A fuse that allowed me to use the original VW vehicle battery cable and crimped tag (with an M6 hole) to connect via it to the Orion XS’s Vehicle Battery terminal. I also modified the battery +ve connection (drilling out the rivet holding the 200A fuse and replacing it with an M5 bolt) to allow a 60A midi fuse to be fitted (shown in second picture).

 

[Snakelimit]

Trying to get my head around lol


I might give up on spit charge wire as it’s only 16mm but I find there 25mm for jump charger from engine as show on ex rac diagram next to side door



Wonder if keep any of wiring for lights etc or just do new new hmmmm