Schaudt WA 121525 only putting in 10a

[DaveS]

I have a 23 model Knaus. I changed over to Lithium 280ah earlier this year and switched over the solar and mains battery charger to Victron adding a shunt at the same time to keep an eye on things.
I left the original Schaudt B2B in as it has a lithium profile, however on our first proper test of the new battery setup over 4 days, I was down to 20%, due to staying offgrid, so when travelling I expected it to be putting in its maximum, 25 or so amps, but it was putting in 10 amps at most and was flicking around zero most of the time not putting anything in.
I was monitoring this via the Fogstar app to see what was going in whilst travelling. It’s the OEM wiring it’s not been changed other than the negative via the shunt.

Any thoughts?
If I switched for a Victron unit i wondered if that would help.

Thanks

 

[MichaelT]

It will also be powering your fridge which will take about 15a. Your solar should keep you topped up so are you sure that's working OK or did it rain for 4 days?

 

[Chrisvh]

I left the Schaudt B2B in my Knaus after changing to Lithium Batteries. Had constant problems so upgraded to a Votronic VV26 50w B2B. Works a treat fully charges 10% to 100% in just over 3 hours of travelling.

 

[treblid]

The Schaudt WA121525 B2B on our Burstner produces a consistent 24A into a 230Ah lithium battery when the SOC requires it. This will be shared with the fridge when it's on its duty cycle but our compressor fridge only takes 3.6A.

 

[Guigsy]

I've put a 30A B2B inline so it feeds into the Elekroblock as if it had come straight from the alternator. I also lose about 15A to the fridge.

I'm not having issues at the moment, 280Ah is way more than I've needed so far. But if I did upgrade, I'd have to wire it straight to the battery as 30A is all I can push through my Elekroblock.

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[Pausim]

As said above if the fridge is taking 15A the best you will get is 10A into the battery. What seems wrong to me is that you say most of the time it is showing around zero. With a smart alternator this is what would happen if there was no booster in the circuit and I am wondering if some of the wiring has been altered during the battery change to Lithium. The D+ connection should ensure the booster is charging consistently whilst the engine is running, not going up and down.

 

[Pausim]

Duplicate.

 

[autorouter]

I have a 23 model Knaus. I changed over to Lithium 280ah earlier this year and switched over the solar and mains battery charger to Victron adding a shunt at the same time to keep an eye on things.
I left the original Schaudt B2B in as it has a lithium profile, however on our first proper test of the new battery setup over 4 days, I was down to 20%, due to staying offgrid, so when travelling I expected it to be putting in its maximum, 25 or so amps, but it was putting in 10 amps at most and was flicking around zero most of the time not putting anything in.
I was monitoring this via the Fogstar app to see what was going in whilst travelling. It’s the OEM wiring it’s not been changed other than the negative via the shunt.

Does the system have an Electroblok? If so what model is it? In EBLs, the fridge circuit is separate from the split charge relay circuit, so if you put in a B2B the fridge should not have any effect on the amps. Have you tried switching off the fridge to see if you then get the full 25A? And also to see if it's still giving near-zero readings.

 

[DaveS]

Thank you everyone! I’d forgotten about the fridge!
However it was sat at zero for a lot of the time.
Does my alternator put out more than 25a so could I say utilise a 12/12 50a with the existing wiring?

 

[DaveS]

Does the system have an Electroblok? If so what model is it? In EBLs, the fridge circuit is separate from the split charge relay circuit, so if you put in a B2B the fridge should not have any effect on the amps. Have you tried switching off the fridge to see if you then get the full 25A? And also to see if it's still giving near-zero readings.

What’s an electro block?

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[Guigsy]

What’s an electro block?

The big blue box with all the fuses that all your electrical connections go through.

 

[Guigsy]

In EBLs, the fridge circuit is separate from the split charge relay circuit, so if you put in a B2B the fridge should not have any effect on the amps.

Not always the case. My fridge feeds via the EBL.

 

[DaveS]

It will also be powering your fridge which will take about 15a. Your solar should keep you topped up so are you sure that's working OK or did it rain for 4 days?

I only have a 100w panel and it was putting in around 5a at best in wales.

 

[autorouter]

Not always the case. My fridge feeds via the EBL.

Yes, but it's usually two independent circuits. The split charge relay input gets power from a thick wire via a 50A fuse near the starter battery, which goes directly to a terminal at the back of the EBL. Its output goes from a terminal at the back of the EBL along a thick wire to a 50A fuse near the leisure battery.

The fridge gets power from a 20A fuse near the starter battery, to an input on the front of the EBL, and then to the fridge relay. The output goes from a connector on the front panel to the HC input of the fridge.

Pulling the 50A fuse has no effect on the fridge, pulling the 20A fuse has no effect on the split charge relay. If the two are interacting after a B2B installation, something has been wired wrong.

 

[Pausim]

Does a Knaus have a Schaudt EBL? I can see a picture online of a Knaus motorhome with a CBE charger, a white 12V distribution system that I do not recognise and a Schaudt WA1215-25. The CBE on my previous system powered the fridge from the leisure battery.

DaveS can you supply pictures of your 12V electrics, particularly the bit with the 12V fuses and the WA.

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[peterc10]

When I put in my 30A Votronic B2B I wired the output straight to the batteries, bypassing the EBL. This supplies the full 30A to charging the batteries. As autorouter says my fridge is fed by a separate circuit when the engine is running.

 

[Pausim]

When I put in my 30A Votronic B2B I wired the output straight to the batteries, bypassing the EBL. This supplies the full 30A to charging the batteries. As autorouter says my fridge is fed by a separate circuit when the engine is running.

That is a sensible feature of Schaudt EBLs but it is not uncommon for other distribution systems to use the leisure battery.

 

[autorouter]

Does a Knaus have a Schaudt EBL? I can see a picture online of a Knaus motorhome with a CBE charger, a white 12V distribution system that I do not recognise and a Schaudt WA1215-25. The CBE on my previous system powered the fridge from the leisure battery.

That's why the first thing I asked was whether there is an Electroblock. Electroblock EBLs are made by Schaudt, so the fact that it has a Schaudt B2B could indicate there is. But it's quite possible to fit that B2B with any other brand of distribution/fusebox, like Reich or CBE. And with most of those fuseboxes, apart from the EBL, the fridge and split charge relay circuit are not separated.

 

[DaveS]

DaveS can you supply pictures of your 12V electrics, particularly the bit with the 12V fuses and the WA.

Sure. I’m on tour at the moment so it maybe a day or two.

 

[DaveS]

DaveS can you supply pictures of your 12V electrics, particularly the bit with the 12V fuses and the WA.

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[Pausim]

I don’t recognise the 12V distribution panel but I think it is highly likely that the fridge is drawing on the leisure battery rather than the engine battery. This would account for only getting a maximum 5A charge. From your description at #1 the fluctuating voltage is what I would expect to happen if the charging was by way of a split charge relay and not via the Schaudt booster. From the picture I can't see the wiring to the booster but the heavy black earth wire seems to run underneath it where the wiring should be visible. Can you see the wiring to the booster? Did you fit the new batteries yourself or get someone else to do it?

 

[DaveS]

I don’t recognise the 12V distribution panel but I think it is highly likely that the fridge is drawing on the leisure battery rather than the engine battery. This would account for only getting a maximum 5A charge. From your description at #1 the fluctuating voltage is what I would expect to happen if the charging was by way of a split charge relay and not via the Schaudt booster. From the picture I can't see the wiring to the booster but the heavy black earth wire seems to run underneath it where the wiring should be visible. Can you see the wiring to the booster? Did you fit the new batteries yourself or get someone else to do it?

I fitted the battery myself, with advice from Offgrid Power Solutions.
And switched over the OEM components to Victron and installed the shunt.
Here’s a slightly better couple of pics.

 

[Pausim]

Offgrid have an excellent reputation. Perhaps have a word with them, explaining what is happening.

 

[bubble63]

There is no temperature probe fitted on the Schaudt/booster is the selector set correctly? Ohne- with out, move it with a ball pen

 

[treblid]

There is no temperature probe fitted on the Schaudt/booster is the selector set correctly? Ohne- with out, move it with a ball pen

To quote the manual:
"If the selector switch for the temperature sensor is in Position ”with” without a temperature sensor connected, the booster has no effect because the output voltage in this case does not exceed 7.5 V.
This mean the leisure area battery is no longer charged."

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[DaveS]

There is no temperature probe fitted on the Schaudt/booster is the selector set correctly? Ohne- with out, move it with a ball pen

Yes it selected correctly. Checked and double triple checked.
The battery is charging, just not consistently.

 

[DaveS]

Offgrid have an excellent reputation. Perhaps have a word with them, explaining what is happening.

Yep have emailed Nigel. He’s away until end of the month will pick up with him when he’s back.