2018 T6 Factory Leisure Battery Question

Scottishstu

New Member
Hi all,

I’ve just picked up a 2018 T6 Startline and found this under the passenger seat (photo attached).

From what I can tell it looks like a factory auxiliary battery setup, but it doesn’t seem to have the usual visible fuse board / split charge setup that I’ve seen in other posts.

I’m planning a camper conversion and want to install:

  • Lithium leisure battery
  • Victron Orion-Tr Smart DC-DC Charger
  • 240V hookup with charger
Just trying to work out the best way forward before I start pulling things apart.

Main questions:

  • Is this actually a live factory aux battery setup or just pre-wiring?
  • Can I reuse the existing cabling (looks like there’s a 100A fuse on the feed)?
  • Cable looks around 10mm² — would you reuse it or run new 16mm² from the starter battery for the Victron?
  • Where would the factory split charge/relay normally be on these?
  • Am I better off stripping it back and starting fresh, or building onto what’s there?

Ideally I’d like to reuse as much as makes sense, but also don’t want to compromise the setup if I’m going lithium + Victron.

Happy to pull the seat and get more photos of wiring/routing if that helps.

Cheers

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I'm guessing it is a factory leisure battery but maybe pull the cover off so we can actually see it?
 
As mentioned in my original post it is the Factory fitted leisure battery

Sorry, I assumed by your question below you were asking whether it was or not.

Main questions:
  • Is this actually a live factory aux battery setup or just pre-wiring?

Anyway, assuming it is, then the thing with the 100 marked on it is likely the split charge relay (verify by checking the connections going into it). You can use the engine run signal going in here as the control input for your new DC-DC. You can reuse the actual input from the starter battery as long as it's fused nicely above the max input current of your chosen DC-DC, to check this just locate the fuses by (possibly under) the starter battery.
 
In all likelihood the factory fusing/cabling will be sufficient as that thing can swing some serious current given it just wires the starter/leisure batteries in parallel when the relay is closed (i.e. when the engine is running).
 
There's also the fuse visible by the relay - check what rating that is. I assume that's the one between the relay and the leisure battery but it's not completely clear from that photo. If I had to guess it's an 80A, which means that the factory cable should be absolutely fine for your DC-DC.
 
There's also the fuse visible by the relay - check what rating that is. I assume that's the one between the relay and the leisure battery but it's not completely clear from that photo. If I had to guess it's an 80A, which means that the factory cable should be absolutely fine for your DC-DC.
Thank you for the info, much appreciated.

I've managed to take some photos (attached)

So as you can see the starter battery and battery under the passenger seat match so definitely factory fitted.

The fuse is beside the relay is 80A. So the live comes into the relay, loops out to the fuse and then onto, lets call it the leisure battery. From the relay there are a brown and black thin cables coming out, any ideas what they are for? Negative is just ground to the earthing point under the seat base.

I'm looking to use a Victron 12 | 12 - 30 DC-DC charger I imagine. If the cables are 10mm2, Victron recommends up to 2 metre runs for that cable type which sounds about right. I've attached the spec sheet from Victron.

Again, appreciate the advice.

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Ok, looks like a standard factory leisure battery setup with 80A fused feed so you are good to go. The wires going into the relay are:

1) Positive in (from starter)
2) Positive out (to leisure via fuse)
3) Engine run signal (small black wire)
4) Ground

These connections are all your DC-DC needs, you've got power in/out, a ground and the engine run signal cable (optional on the DC-DC but very much recommended if you have it). So you can reuse cables 1,2,3 there, for the ground you probably need to pick up a ground (with cable size at least as big as the positive feeds) from the seat ground or leisure battery because it's very unlikely the one going into the relay is sufficient (because all it's carrying is the tiny signal current that activates the relay).

Note that that Victron specifies 60A fuses so you can always fuse the inputs at that to be safe.

Incidentally, check the exact model of DC-DC you want there because I have a feeling the one pictured might be their old unit which was very inefficient and so ran very hot. The new one is the "Orion XS" or similar.
 
Hi all,

I’ve just picked up a 2018 T6 Startline and found this under the passenger seat (photo attached).

From what I can tell it looks like a factory auxiliary battery setup, but it doesn’t seem to have the usual visible fuse board / split charge setup that I’ve seen in other posts.

I’m planning a camper conversion and want to install:

  • Lithium leisure battery
  • Victron Orion-Tr Smart DC-DC Charger
  • 240V hookup with charger
Just trying to work out the best way forward before I start pulling things apart.

Main questions:

  • Is this actually a live factory aux battery setup or just pre-wiring?
  • Can I reuse the existing cabling (looks like there’s a 100A fuse on the feed)?
  • Cable looks around 10mm² — would you reuse it or run new 16mm² from the starter battery for the Victron?
  • Where would the factory split charge/relay normally be on these?
  • Am I better off stripping it back and starting fresh, or building onto what’s there?

Ideally I’d like to reuse as much as makes sense, but also don’t want to compromise the setup if I’m going lithium + Victron.

Happy to pull the seat and get more photos of wiring/routing if that helps.

Cheers

View attachment 323572
That's the factory leisure setup.

With the OEM split charge relay, and fuse.

That's what I had.....I removed the relay and fitted a DC DC. Charger.

Replaced the fuse and battery.




.
 
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