CBE DL30 Split charge relay LiFePO4

[BordoCamp]

Hello all,

I plan to install a Victron Orion XS DCDC to a CBE DL30-RA unit.

First plan is to disable the split charge relay that is coupling the two batteries together when KEY or/and D+ signal is ON.
CBE 230V charger will still be charging the motor battery since I presume the charging line doesnt go through the split charge relay.
Second is to run a 16mm2 wire from motor battery to DCDC and from DCDC to Lesiure battery.


Now lets say that I have the Orion XS set to 45A of charging current.
AES fridge is running on 12V when engine is ON and it is taking approx 15A (diff upon fridge type).
My Lifepo4 battery will be charged with 30A.

What would be most simple and efficient way to wire the fridge directly to the motor battery and so all current from Orion XS goes to the Lifepo4 battery ?


Thank you

 

[LithiumConvert]

You logic sounds good, although I would not expect the alternator charging of the engine battery to go via the CBE.
It is more likely to go direct - alternator to battery.

Not that, that will affect your logic and calculation.

I agree with your logic of running the fridge off the alternator instead of the B2B, but you will need a D+ signal to activate it and I do not know where the wires are to move fridge suuply from one battery to the other.

Do let us know how you get on.

 

[AdrianChen]

Would be good to know which van you have - and also if it has been "rewired" in its past.

Our van came from the factory with the 180amp alternator connected directly to the starter battery, since that was how it was built by Iveco.

Carthago then added the hab batteries etc. They added a 16mm² cable running from the Iveco fuse panel to the split charge relay which operates like your separate box, but is integrated into the main distribution/fuse box, and a further 16mm² went from there to the leisure batteries. The fridge when operating on 12v got the supply from the leisure batteries, which in turn were being recharged via the scr. Net result was not much went into the batteries. The standard wiring used that same 16mm² cable to charge the Hab batteries with the engine running, and the Cab battery (From solar or EHU) when the engine was stopped.

When we put our Lithium bank in (to replace the original Gel batteries) we had a similar situation to you.

Firstly we decided how much amperage it was OK to get from the alternator, given it still has to run the vans lighting, wipers heater motors etc. I decided 40% of the alternators output was the max we should add to its load - We used an Orion XS which could take 50amps, so I have another 30amps headroom I guess.

Our van is 8.6m, and that 16mm² cable Carthago fitted has an overall run of 10m by the time it has gone from front to back, round the hab door, up and down in a few places. 16mm² was too small a gauge for 50amps of current over that length without incurring a fair bit of voltage drop, IIRC about 1v. So in therory 35mm² would be a lot better.

The fridge would use some of the 50amps that I would like to be charging the battery, and I do have the alternator capacity to run the fridge as well, but it would mean rewiring the fridge main 12v supply, which I have a plan for but haven't done yet.

We also needed to disable the vans SCR, which in our case is simple to do by removing a link within our distribution/fuse box.

and we need to put in a new suitably fused 35mm² cable run along the chassis to close to the batteries in our garage.

Then the new B2B input will be from this new 35mm² cable (Fused at 60amps), the B2B's output will run to the main busbar that the batteries are connected to, they are very close so will probably use 25mm for convenience.

The old 16mm² cable is still in place, but will only supply a voltage reading for the CBE display panel, and a trickle charge to the Cab battery when there is either EHU or Solar in operation (The main panel also has to be switched on). I may try using that as the 12v supply to the fridge with a relay to control it from D+ since it is there.

We also have an Ablemail trickle charger to keep the Cab battery topped up when the van is in storage, wired in to the B2B.

Being lazy I'm only half way through this lot, but it's slowly getting there, along with some other plans......

So for you I think it would be good to map out exactly what you do have, and let folk know so you can get better/more accurate advice.

Good luck with the project!

 

[BordoCamp]

Hello and thank you for the fast replys.

My base vehicle is a Fiat Ducato.
Alternator outpus is 150A and with an idle running car I measure up to 60A going to the motor battery form the Alternator. If I am not mistaken alternator output goes directly to the motor battery.

This is also the point where I plan to connect/wire a 1,2m long 16mm2 cable from+ Motor battery to the DCDC input. Sutiable fuse will be used. DCDC output goes directly to the leisure battery + and not DL30 B2. Output cable is 0,8m long with sutiable fuse. No long distances.
Running at full Orion XS capacity (50A if needed) it will consume up to 110A. 40A is on reserve for any other frequent devices.

LithiumConvert if I am not mistaken newer CBE distribution boxes have a separate line for charging motor battery with (PTC to keep current under 2A) when camper is connected to 230V
When disabeling the split charge relay motor battery will no longer be connected to leisure battery and no charging cuurent will go to leisure battery like in original wiering setup.

AdrianChen you have some long distances and yes i agree you should use appropriate cables diameter.
Is your distribution device DL30 or any other ? I assume DS300 since you are mentioning a simple ling (0Ohm resitor) ?

Fridge connection is located on the leisure side of the split charge relay.
For the case of how to to wire the fridge directly to motor battery my idea for now is to cut the wire that is going from DL30 to the fridge. This is the wire that has a 30A fuse. Use an additional fuse holder and wire it directly to B1 connection on the DL30.
Your thoughts ?

Also connectors within different EBL/distribution boxes are not up to the 30A fuse rating if you ask me and on my previous camper that had NE196T installed, there was some melting of fuse due to long driving hours and thus for running fridge on 12V for up to 7 hours.

Regards.