Knaus 2007 lithium conversion with b2bs changing wiring to disable split charge relay etc (1 Viewer)

[PeterCarole29]

Hi
Help needed for technical advice on how to finish my install
I have fitted fogstar batteries
2x victron 12 12/30 Bluetooth B2Bs
Victron solar controller

I don’t know how to disable the original split relay charger as it will also do the fridge for when travelling also I am unsure where it is
So help needed please
Also how to connect what’s referred to as D+
Wires to b2bs

 

[PeterCarole29]

 

[PeterCarole29]

This is a photo of the Liesure side fuses and assume something simular will be next to the starter battery

 

[PeterCarole29]

Under passenger seat

 

[PeterCarole29]

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[PeterCarole29]

Last photo is behind passenger seat mounted on metal frame of dinning seats

 

[PeterCarole29]

This is one 30 amp fuse and 2 x 4 amp

 

[Jev88]

Amateur suggestion but pull a fuse and measure leisure battery charge at battery with engine running. One should disable split relay.
I have to do similar to disable Emergency Start solenoid on our bus that behaves like a battery master as a bonus (unless you install lithium then best turned off).

 

[PeterCarole29]

Amateur suggestion but pull a fuse and measure leisure battery charge at battery with engine running. One should disable split relay.
I have to do similar to disable Emergency Start solenoid on our bus that behaves like a battery master as a bonus (unless you install lithium then best turned off).

Thanks for the reply untill i can determin how to do it and not disable the fridge and anything else i may just put back one lead acid battery connect it back just to the habitation side and keep inverter and lithium side separate so i dont damage anything

 

[Jev88]

Thanks for the reply untill i can determin how to do it and not disable the fridge and anything else i may just put back one lead acid battery connect it back just to the habitation side and keep inverter and lithium side separate so i dont damage anything

Or until you get a pro to disable it you could have one lead for driving and a switch to select battery 2 (lipo) when stationary?

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[PeterCarole29]

If I remove the first 4amp fuse with the engine running the light goes out on the fridge on 12 v and it will still work on gas
So a assume this fuse disarms the split charge relay
But what do you have to do to have your fridge to then run on 12 v whilst traveling

 

[autorouter]

I don't know where the split charge relay is, maybe others with this Calira VB 05 fusebox will know. But I know where it isn't. It's not in the Calira VB 05 fusebox, because there is no power connection to the starter battery, which would definitely be required if the split charge relay was in this fusebox. There are some thin battery sensor wires, with 2A fuses, used for measuring the battery voltages. But no power connection.

And it's also not inside the mains charger unit, because there is no D+ feed to the mains charger. The two 30A fused wires to the starter and leisure batteries are just for charging them from the mains.

You can easily check if the split charge unit is operating, by looking at the voltages of the starter battery and the leisure battery. First make sure there is no other charging (mains, solar). Measure the two battery voltages. They should be less than 13V. Start the engine. The starter battery voltage should rise, to over 14V. If the leisure battery voltage also rises, then the split charge relay is operating. If it doesn't rise, then the split charge relay is not operating.

The upside is, if the split charge relay is somewhere external to the fusebox, then once you find it, it will be very easy to disable. And it should have no effect on the fridge etc.

 

[PeterCarole29]

I don't know where the split charge relay is, maybe others with this Calira VB 05 fusebox will know. But I know where it isn't. It's not in the Calira VB 05 fusebox, because there is no power connection to the starter battery, which would definitely be required if the split charge relay was in this fusebox. There are some thin battery sensor wires, with 2A fuses, used for measuring the battery voltages. But no power connection.

And it's also not inside the mains charger unit, because there is no D+ feed to the mains charger. The two 30A fused wires to the starter and leisure batteries are just for charging them from the mains.

You can easily check if the split charge unit is operating, by looking at the voltages of the starter battery and the leisure battery. First make sure there is no other charging (mains, solar). Measure the two battery voltages. They should be less than 13V. Start the engine. The starter battery voltage should rise, to over 14V. If the leisure battery voltage also rises, then the split charge relay is operating. If it doesn't rise, then the split charge relay is not operating.

The upside is, if the split charge relay is somewhere external to the fusebox, then once you find it, it will be very easy to disable. And it should have no effect on the fridge etc.

Thankyou
Am i right to be conserned that before i turn on the B2Bs i need to disconnect the origal split chargers on the van
Can you guess what the first 4 amp fuse does next to the engine battery in the last photo as when engine is running and fridge is turned onto 12v the green light goes out on the fridge when i take out that fuse.
I will try and find the split charger now and do the tests you have kindly suggested
Many thanks Peter

 

[autorouter]

Can you guess what the first 4 amp fuse does next to the engine battery in the last photo as when engine is running and fridge is turned onto 12v the green light goes out on the fridge when i take out that fuse.

I think it's a fuse for the D+ control signal from the alternator - the thin brown wires. The other small fuse with the thin red wire is a battery sensor wire, which allows the control panel to measure the starter battery voltage without any voltage drop that might occur over the thick power wire (the big fuse).

I think that fuse controls all the D+ signal, to the split charge relay and to the VB05 fusebox. From there it controls the fridge and no doubt other things like the awning light.

 

[PeterCarole29]

With engine running starter battery 14.51
With it not running starter battery 13.72(with no time to rest)

Lithium 2x460ah 13.65v at rest
With engine running

At fridge at wires that feed 12v element before it’s switched on 13.73 with engine running with 30amp fuse in
13.66 with fuse out and fridge light still green so can i assume 30amp fuse is for split charger

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[PeterCarole29]

The green light that was still on after fuse had been taken out was residual live still in the circuit as now it doesnt light up with the fuse out
so i do think its the fuse for the split charger.
What i dont know is how do i know power the fridge whilst driveing

 

[PeterCarole29]

I don't know where the split charge relay is, maybe others with this Calira VB 05 fusebox will know. But I know where it isn't. It's not in the Calira VB 05 fusebox, because there is no power connection to the starter battery, which would definitely be required if the split charge relay was in this fusebox. There are some thin battery sensor wires, with 2A fuses, used for measuring the battery voltages. But no power connection.

And it's also not inside the mains charger unit, because there is no D+ feed to the mains charger. The two 30A fused wires to the starter and leisure batteries are just for charging them from the mains.

You can easily check if the split charge unit is operating, by looking at the voltages of the starter battery and the leisure battery. First make sure there is no other charging (mains, solar). Measure the two battery voltages. They should be less than 13V. Start the engine. The starter battery voltage should rise, to over 14V. If the leisure battery voltage also rises, then the split charge relay is operating. If it doesn't rise, then the split charge relay is not operating.

The upside is, if the split charge relay is somewhere external to the fusebox, then once you find it, it will be very easy to disable. And it should have no effect on the fridge etc.

Thanks for all your advice I think i have now got to the bottom of it. I undid the cover for the engine battery to see if the relay was hidden there to find the first 4 amp fuse was not in its slot one side . Ah i thought maybe the fridge will work now

SUCCESS still with the 30amp fuse removed has stopped the split charge from working and the fridge is being powered by the liesure side so i have had to do nothing
Gone for a drive and confirmed fridge working as it should

 

[autorouter]

Great, at least the fridge is working OK now, and the split charge relay is disabled. I think you need to check that the starter battery is still being charged from the mains charger when on hookup. It looks to me like that wire with the 30A fuse carries that charge from the charger to the starter battery. But even if it doesn't work, it may not be much of a problem, there are other ways to keep the starter battery charged. A BatteryMaster, for example.

 

[PeterCarole29]

Thankyou good advise as always

did that today it’s hard to see but battery master is sitting on top of the negative bus bar case
It’s the shiny side up

 

[PeterCarole29]

B2Bs bolted to metal seat base with 3 fans when needed

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