Leisure batteries alternator charging issues

[jancsi]

Hello, I own a 2019 Mercedes sprinter hymer Grand Canyon S camper van. I just installed two Lifepo 150ah house batteries, the brand is called ultimatron. I set the Schaudt booster WA121545 to lithium, the power reduct is C3 and the max charge set to 45A, I also set the ebl 30 to gel, and changed the solar to lithium. When I start the van, the batteries charge for about a minute then the charging stops entirely. This problem was also with AGM batteries, actually I think I have always had this issue since I bought the van new… If I turn off the car and restart it, the charging starts again then stops again after one minute. The batteries are charged only 45%, not close to full capacity. Does anyone know what might be causing this? Has anyone had this issue before? Thanks for any help, greatly appreciated

 

[Lenny HB]

Check the D+ connection to the B2B should have 12v present when the engine is running.
The D+ won't come direct from the alternator but via a Schaudt relay unit.

 

[AdrianChen]

Does your van have a smart alternator fitted?

Lenny will know better than me, but if so would C1/C2 setting for reduct be more appropriate?

 

[Lenny HB]

Does your van have a smart alternator fitted?

Lenny will know better than me, but if so would C1/C2 setting for reduct be more appropriate?

Certain it will be a Smart Alternator being a Merc they have had them on campers since around 2014 but Hymer only started fitting B2B's around 2017/2018.

 

[Pausim]

Certain it will be a Smart Alternator being a Merc they have had them on campers since around 2014 but Hymer only started fitting B2B's around 2017/2018.

I had a 2015 Hymer Mercedes with smart alternator but no B2B. I very rapidly discovered the problem and fitted one.

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[jancsi]

Check the D+ connection to the B2B should have 12v present when the engine is running.
The D+ won't come direct from the alternator but via a Schaudt relay unit.

Ok will try, not sure how to proceed but will have a look. Thanks

 

[jancsi]

Certain it will be a Smart Alternator being a Merc they have had them on campers since around 2014 but Hymer only started fitting B2B's around 2017/2018.

I have no idea what the alternator is and not sure how to find model/type… but I do believe that it’s at the core of the problem. I think van is 2019 but first in service date is spring 2020. Thanks for the help.

 

[jancsi]

I had a 2015 Hymer Mercedes with smart alternator but no B2B. I very rapidly discovered the problem and fitted one.

This might be the solution I think, I’m on the road in Sardinia for next month so will have to wait till I get back.. thanks for reply

 

[MichaelT]

Does it start to charge after a few minutes of the engine running, and does fridge go to 12v when its running?

 

[AdrianChen]

I have no idea what the alternator is and not sure how to find model/type… but I do believe that it’s at the core of the problem. I think van is 2019 but first in service date is spring 2020. Thanks for the help.

In that case I would try C2, and see if that cures the problem. Manual recommends c1/c2 with smart alternators, I had to check the online manual since I have only a scant memory of the WA121545 from research when considering what to buy for my van.....

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[autorouter]

This might be the solution I think, I’m on the road in Sardinia for next month so will have to wait till I get back.. thanks for reply

You have a B2B fitted already. A Schaudt Booster WA121545 is a B2B (Battery to Battery Charger), also called a DC-DC Charger.

The problem might be with the method used to trigger the B2B on and off. There is a something called the D+ signal, sent out by the alternator to show it is producing power. This signal is used in a motorhome for many things, like turning the fridge to 12V when the engine starts, and back to gas then the engine stops. Also to make sure the awning light is off while driving. It is a good idea to use this D+ signal to turn the B2B on and off.

If the D+ signal is not used, then the B2B can try to guess when the engine is running by looking at the voltage at the input, which comes from the alternator output.

With a standard alternator, the input voltage to the B2B is a constant voltage, about 14.5V, all the time the engine is running, and it drops down to about 13V when the engine stops. It's easy to use this fact to switch the B2B on and off.

With a smart alternator, it's not so simple. The voltage goes up to 14V or more when the engine starts, but after a short time it drops down to maybe 12.5V. During overrun and braking the voltage increases to over 14V, but soon drops back to 12.5V again. If this voltage is used to trigger the B2B, then you will get the scenario you describe, with charging stopping after a minute or so.

The B2B will in fact charge the leisure battery perfectly well from a 12.5V supply, if it is triggered to do that. So the solution to your problem is to find a way to trigger the B2B from the D+ signal.

 

[Lenny HB]

If you look at the battery negative terminal if it has a smart alternator it will have a shunt on the terminal, a small black box.

 

[jancsi]

Does it start to charge after a few minutes of the engine running, and does fridge go to 12v when its running?

It starts to charge immediately when engine starts then stops after one minute, fridge is always on 12v

 

[jancsi]

If you look at the battery negative terminal if it has a smart alternator it will have a shunt on the terminal, a small black box.

Thanks I’ll have a look

 

[AdrianChen]

I presume the vehicle engine battery is always fully charged or at least the van starts ok?

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[MichaelT]

It starts to charge immediately when engine starts then stops after one minute, fridge is always on 12v

Yes but does it then start after a couple of minutes? Victron ones have a delay to allow starter battery to recover.

When you say fridge always on 12v is it compressor, I maybe wrongly assumed it was a 3 way with AES.

 

[autorouter]

Is there a 12V distribution/fusebox, if so what make/model is it? A D+ signal is usually easily available on one of the terminals.

 

[jancsi]

Wow thanks for explanation, yes I’m pretty sure this is where the problem lies… now what to do about it and why am I alone with this

In that case I would try C2, and see if that cures the problem. Manual recommends c1/c2 with smart alternators, I had to check the online manual since I have only a scant memory of the WA121545 from research when considering what to buy for my van.....

thanks so much for your reply much appreciated

 

[jancsi]

Wow thanks for explanation, yes I’m pretty sure this is where the problem lies… now what to do about it and why am I alone with this

thanks so much for your reply much appreciated

Yes but does it then start after a couple of minutes? Victron ones have a delay to allow starter battery to recover.

When you say fridge always on 12v is it compressor, I maybe wrongly assumed it was a 3 way with AES.

No it won’t charge again after the initial first minute of charge. Yes fridge is compressor only. Thanks again

 

[jancsi]

Is there a 12V distribution/fusebox, if so what make/model is it? A D+ signal is usually easily available on one of the terminals.

Not sure, it is a hymer sprinter Grand Canyon, 2020, there is an ebl 30 and schaudt 121545 booster. Other wise a fuse box under drivers seat. As you can tell I’m a bit clueless as to where to find the D+ signal…

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[berni109]

There will be a d+ signal on the EBL. Check the manual and then tap into the wire after it leaves the EBL.
Surprised there is not already a d+ from the EBL to the B2B. Is there a fuse that blown on the EBL output.

 

[berni109]

 

[autorouter]

The manual for the EBL 30 ia available from the Lippert website, in the Support Documentation section:

https://res.cloudinary.com/lci-cloudinary/image/upload/v1694803226/lippert-eu/support/power-on-board/pdf/anleitungen/911/9110305/8110305_2018-10-15_EBL_30_EBL_30_mit_OVP_BA_EN.pdf

There is a wiring diagram near the end of the manual. The D+ signal comes into the EBL on the 5-way connector Block 2, Pin3. The D+ signal leaves the EBL on the 4-way connector Block 1 Pin2. Usually the wire is yellow.

That wire is intended to switch the fridge to 12V when the engine is running. You could check to see if there is already a D+ signal wire from Block1 Pin2 to the Schaudt Booster.

If there's a wire already there, maybe the fuse has blown. The fuse is on the input wire to the EBL, on Block2 Pin3. It's a 2A fuse, usually located near the starter battery end of the wire. Probably next to the main fuse to the EBL from the starter battery, which is probably a big 50A or 60A Maxi fuse. In fact there's usually 3 fuses, the third being a 20A fuse to supply the heater element of a 3-way fridge, but maybe that third fuse isn't there if your fridge is a compressor type.

 

[LithiumConvert]

Hymer don't always connect the D+ to the EBL 30.

On our Exsis-i 580, there is no D+ signal connected to the EBL 30.
Connector Blocks 1 and 2 (for the fridge) are both unpopulated - nothing is connected.

The Grand Canyon may be the same.

The EBL 30 acts as an EHU leisure battery charger - always on when connected to EHU.
I have it set to GEL to charge the lithium leisure batteries

The Schaudt WA 121545 has the D+ signal and hence it is always charging when the engine is running.
I have it set to 45amp and lithium.
I have left the Power Reduct setting as it came from Hymer - C1: EURO6-Generator without input voltage sensor.

The fridge just magically looks after itself - I have not investigated how - other than it is not connected to the EBL

 

[LithiumConvert]

So, I suggest you may need to change the Power Reduct setting on your Schaudt B2B to C1 (not C3)

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[jancsi]

In that case I would try C2, and see if that cures the problem. Manual recommends c1/c2 with smart alternators, I had to check the online manual since I have only a scant memory of the WA121545 from research when considering what to buy for my van.....

Hi, thanks for trying to help me, I tried C1 and C2 and it’s the same result, charging from alternator cuts off after one minute.

 

[AdrianChen]

Hi, thanks for trying to help me, I tried C1 and C2 and it’s the same result, charging from alternator cuts off after one minute.

Oh sorry I didn't help!
So I can only assume there must be a fault in the wiring on the feed into the WA121545, perhaps the fuse is not working properly, or is loose in the fuse holder.....

 

[jancsi]

So, I suggest you may need to change the Power Reduct setting on your Schaudt B2B to C1 (not C3)

Hi, thanks for trying to help me, I tried C1 and C2 and it’s the same result, charging from alternator cuts off after one minute… so maybe it needs a new B2B

 

[AdrianChen]

Hi, thanks for trying to help me, I tried C1 and C2 and it’s the same result, charging from alternator cuts off after one minute… so maybe it needs a new B2B

Well I would go through the wiring first, and check there are no faulty/high resistance connections causing a voltage drop.

I guess measuring the voltage at the input terminal (Should be around 13v) and at the D+ connection (should be above 12v) when the charging has stopped might give you some idea if the B2B is faulty, or if its a wiring or alternator issue?

 

[1967bowesj]

Hi, thanks for trying to help me, I tried C1 and C2 and it’s the same result, charging from alternator cuts off after one minute… so maybe it needs a new B2B

Is there still power to the b2b when it stops charging?

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