Does my van have a B2B ? (1 Viewer)

[berni109]

2019 sun living (by adria) not a smart alternator.
According to the conversation spec I should have a schaudt WA121525 B2B somewhere in my van. The operation manual for it came with the vehicle.
It's not under the passenger seat as I have had that out and it's full of battery and solar controller and the ebl211 is under the driver's seat with a rats nest of wires behind it but no B2B.
Really nowhere else for it to be is there?

Can I test if it's hidden somewhere under the floor (certainly not in any accessible area) by measuring the charging amperage?

If I run the hab battery down to 50% soc and then run the engine at about 1500rpm should I see 25amps if there is this elusive B2B hidden somewhere ??

Any idea what the amps would be if it's just the output from the split charge relay in the ebl 211 that I would be seeing ??

If I remove the fuse for the internal charger in the ebl211 will this disable output from split charge relay ??

Thanks for any suggestions
Bern

 

[Jewellbags]

I’m certainly no expert (we have a B2B) but would have thought that it would remain accessible if you had one as you can adjust the split of charge between Hab and engine . Just a thought

 

[1967bowesj]

Having googled it, it is a canny size so you should be able to see it, and it charges at upto 25amps, mind it get about 18-20 from a split charger, unless I have a hidden b2b lol

 

[LostInSpace]

It is a good question.

We had our new Hymer for many months before I found the Schaudt B2B. Other funsters said we must have one, but I found no evidence of it.

Eventually, it turned up one day not working because Hymer had not fastenned the plug clips and the plugs had fallen out.

Simple job to put right and it now works fine, leaving me with a spare B2B as I had fitted my own in the mean time.

Anyway, enough of my digressions, look for yours in places like under a hatch in the floor, behind the batteries and under the other seats. It does need some ventilation (perhaps a bit more than Hymer give it!)

When looking at charging rates, remember that when driving the fridge will take about 15 of the B2Bs amperage, which does not leave a lot.

as you can adjust the split of charge between Hab and engine

The schaudt 121545 can not do that.

The Schaudt does have settings for the battery type and charging rate, so I agree, it needs to be accessible.

Finally, if you do not have a smart Alternator, then the need for a B2B disappears unless you have lithium batteries.

 

[PeterCarole29]

Just for info we have a 3 way fridge RM7351 and just been for a run to test something to do with the fridge and it was from 24 degrees inside so had not been on and was using 5 amps to start cooling

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[stevewagner]

I’m certainly no expert (we have a B2B) but would have thought that it would remain accessible if you had one as you can adjust the split of charge between Hab and engine . Just a thought

A B2B charges the hab batteries not the cab batteries.

 

[1967bowesj]

A B2B charges the hab batteries not the cab batteries.

Think jewellbag is mistaken for the solar controller

 

[Pausim]

My booster is on the back of the seat base behind the EBL, hidden by a plastic grill/trim.

 

[canopus]

On our Carado (right hand drive) CV640, the Lippert (Schaudt) WA 121545, is mounted behind the EBL31, which in turn is mounted beneath the passenger seat.

 

[Jewellbags]

Think jewellbag is mistaken for the solar controller

Yep I am and it is

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[berni109]

Yes makes no sense to me that it would be hidden away in an inaccessible location.

 

[autorouter]

The B2B is 25A, which is within the capability of the EBL211 wiring. So it could be mounted anywhere between the starter battery and the EBL.

Basically, if there was no B2B, and a split charge relay was present, there would be a wire from the starter battery to the starter battery input of the EBL. The split charge relay would connect it to the leisure battery when the engine was running.

To wire in a B2B, one way to do it is to cut the wire from the starter battery to the EBL. Then wire in the B2B: starter battery input to starter battery, leisure battery output to the EBL starter battery input. This method works for lower amps B2Bs like 25A, but is not suitable for say a 60A B2B because the EBL internal wiring won't take 60A.

In this method, the split charge relay is connected to the B2B, not the starter battery. The amps from the B2B flows through the split charge relay, so there is no need to disable it.

 

[autorouter]

Just for info we have a 3 way fridge RM7351 and just been for a run to test something to do with the fridge and it was from 24 degrees inside so had not been on and was using 5 amps to start cooling

Sorry to say this, but I think a 3-way fridge should be using at least 10A. That's for a smaller fridge. My 3-way fridge uses 14.4A when it's on 12V.

 

[PeterCarole29]

I got the model number from a manual
I would consider mine a small fridge freezer
I took the amp reading from the fogstar app
Come to think of it
My app shows 2 batteries which I have I clicked on one and it showed a draw of 5 amps
I assumed this was what it was using is it posible that it’s using 5 amps from each battery

 

[berni109]

Off to grovel about in the van again for another look.
Thank you autorouter for the suggestion of splicing a new lower power B2B between the starter battery and the EBL which is an option if I can't find the one that is supposed to be there.
I found in another thread the idea of isolating the output from EBL to hab battery (lithium) using a 50A diode. I could then connect a new B2B directly between batteries without worrying about a/the split charger
In the extreme necessity of needing to use the EBL internal charger (all be it with the wrong charge profile) a 2 way switch to bypass the diode would work.(I think).
Any other ideas gratefully received.

Please if you want to talk about fridges start another thread.

Bern

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[Tombola]

I got the model number from a manual
I would consider mine a small fridge freezer
I took the amp reading from the fogstar app
Come to think of it
My app shows 2 batteries which I have I clicked on one and it showed a draw of 5 amps
I assumed this was what it was using is it posible that it’s using 5 amps from each battery View attachment 933737

My app isn't fogstar, but KS energy and yes I have to double the shown amps in or out...as its across 2 batteries.
It shows each battery individually but not sure about fogstar

 

[autorouter]

the suggestion of splicing a new lower power B2B between the starter battery and the EBL which is an option if I can't find the one that is supposed to be there.

You could see if there is a B2B in that wire already by looking at the voltage on the EBL starter battery input. If it's just a continuous wire, the voltage will be the same as the starter battery, all the time. If there's a B2B in there somewhere, there will be about zero voltage when the engine is stopped, and a high voltage when the engine is running. The voltage should be about the same as the alternator voltage, but maybe a bit different, not exactly the same if there's a B2B.

 

[PeterCarole29]

Off to grovel about in the van again for another look.
Thank you autorouter for the suggestion of splicing a new lower power B2B between the starter battery and the EBL which is an option if I can't find the one that is supposed to be there.
I found in another thread the idea of isolating the output from EBL to hab battery (lithium) using a 50A diode. I could then connect a new B2B directly between batteries without worrying about a/the split charger
In the extreme necessity of needing to use the EBL internal charger (all be it with the wrong charge profile) a 2 way switch to bypass the diode would work.(I think).
Any other ideas gratefully received.

Please if you want to talk about fridges start another thread.

Bern

Don’t know how I managed to post the fridge on this thread but yes off course

 

[Lenny HB]

If you don't have a smart alternator I very much doubt you will have a manufacturer fitted B2B.

As you have Lithium I wouldn't use a Schaudt B2B as on the Lithium setting they just output a constant 14.2v and doesn’t shut down when the battery is charged.

Also on manufacture fitted B2B the fridge also runs from the B2B so you lose upto 15 amps.

My new van was fitted with a Schaudt 25 amp B2B, I have disconnected it and fitted a 50 amp Victron B2B. If I can sort out the Carthago wiring I will use the Schaudt unit just to run the fridge.

 

[berni109]

Special thanks to autorouter Lenny HB and dawsey for his solution in previous thread. https://www.motorhomefun.co.uk/forum/threads/preventing-ebl-from-charging-lithium-batteries.297825/

I think it's conclusive there is no B2B in my van from the measured voltages just a rats nest of wires and a choc block connector where it should have been.

The plan is to install an Orion 12-12-30 as the following diagram. Also to introduce a 5 way relay and 50A diode into the current wiring so if ever short of power when on hookup could get some juice back into the hab battery. (I know it's the wrong charge profile).

Your critique of the above would be appreciated.
Thanks once again
Bern

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[autorouter]

I'm not sure the diode thing is necessary. If you simply unplug the starter battery connection from plugs 3 & 4 on the EBL front panel, that will prevent current from the alternator/starter battery reaching the split charge relay. This won't cause any problems, because the relay is off when the engine is stopped, and there are no other wiring branches inside the EBL before that relay.

The diode idea is used with other makes of distribution block, where the starter battery functions(split charge, hookup charging, voltage measurement etc) are all on the same wire. In Schaudt (Lippert) EBLs they are separate.

 

[Lenny HB]

I agree with autorouter you are making it unnecessarily complicated.
The Orion XS 50 amp B2B is not much deared and is programable from 1 to 50 amps output it also runs a lot cooler.

 

[autorouter]

At that choc block connector, I'd guess the red wires on the right go to the hab and cab batteries, you need to find out which is which. The thick black wire is the negative, and the thin black wire is the D+.

The starter battery red wire goes to the B2B starter battery input. The other pair of red wires presumably goes to the EBL front panel connectors 3 & 4, and I think they are now unnecessary (see previous post).

The leisure battery red wire, plus the pair of red wires, need to be connected to the B2B Leisure battery output. You might need to connect them together with a bigger choc block, or better still a Wago connector block. I'd use the 6mm² 221 type, 3-way or 5-way.

Same with the negative wires, and the D+ wires.

Wago 221 5 Way Compact Lever Connectors

A five-way compact splicing connector with handy lever for quick and hassle-free installations. Use this pack of reusable Wago 221 connectors for solid, stranded and flexible cables.These connectors couldn’t be easier to use – simply pull the lever up to 90°, insert a stripped conductor and push...

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[berni109]

Quick final update.
Fitted a s/h Orion isolated B2B 12-12-30.
Bit of a tight fit at the back of the seat base but it's in now and the cable runs have been kept to a minimum.
Slight concern about the heat that will be generated when I put the basecover back on the seat but if necessary a couple of small computer fans should solve that.