B2B charger issue

RobinE

RobinE

Joined
Jul 13, 2019
Posts
76
Likes collected
101
Location
Milton Keynes, UK
Funster No
62,386
MH
Hymer Bclass ML 780T
Exp
Since 2003
Looking for a little guidance please.

The Hymer stock 40 amp charger has failed and needs replacing as identified by the good folk at Vanbitz the day after I purchased the Van from Lowdhams in mid March.

I am trying to get it replaced under warranty which is proving a long tortuous and stressful process - likely to become a subject of another thread.
As I am really needing this charger to avoid visiting sites with hookups, I am thinking of avoiding further stress and splashing out on a replacement 3rd party unit which look to be less than £400. The Hymer unit is close to £1000:

I am not confident to instal myself, so looking for recommendations from Funsters for an installer reasonably close to me in Milton Keynes? (Roadpro are booked up until September)

Also do I need to look for anything specification wise when choosing a unit other than it being 40 amp, Lithium compatible and 12volt,? The base vehicle is a 2021 Mercedes Sprinter 417. A 70 amp charger would be very nice and cost very little more, would my alternator take it, how do I find out?

For info I have a Stirling 300 AH Lithium battery and Victron charger/inverter fitted by Vanbitz.

Thanks
 
Good morning all, I was hoping someone would be able to offer some guidance or recommendations? I am really not sure what to do.
Thanks
 
I'm not sure whether this is true of all Hymers, but I think they always used to be fitted with a high output alternator, so it's likely that a 70A B2B charger would not be a problem. But you'd need to double-check that, probably have to look at the label on the alternator to find out.

There a number of good B2Bs, also called charger boosters or DC-DC Chargers. It will need to have a lithium battery setting in its range of charging profiles. Also with a lithium battery you will want one that can take a battery temperature sensor so that the B2B won't charge it if the temperature is zero or below.

Sterling B2Bs have a range of outputs. They have a half power mode, so you could set a 70A one to 35A if you want. They have a lithium profile setting, and can take a temperature sensor.

Victron do a 30A DC-DC Charger - you want the 'non-isolated' version which is a bit less expensive than the 'isolated' one. They are designed so that more than one can be wired in parallel if you want higher power. They also have a lithium setting and can take a temperature sensor.

There are others available, of course.
 
I assume it is Schaudt 40 amp B2B that has failed, Schaudt do a repair service but may workout expense & customs issues shipping to and from Germany.

You should be able to fit any B2B should be a straight swap, I would look at the Votronic range they go up to 90 amps.

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I suspect your van has a smart alternator. A votronic B2B would be fine. They come in several sizes 30A 50A and higher. The 50A you can reduce the output so this might be helpful if the original B2B gets repaired or replaced as it should be okay to have them working in parallel but you might be concerned about overloading the alternator. I suspect you have a powerful alternator however in a 2021 Merc with the 170bhp engine.
Can't help with fitting I'm afraid.
 
Whilst it may be an easy swap out going for a replacement DCDC charger, you need to check the cable size going to the lithium battery if you decide to go for a much higher output B2B than the one you have fitted.
 
I live not far from you, and it’s hard trying to find a competent motorhome electrician. Had an issue a couple of weeks ago so had a word with ash at Vanbitz who had a cancellation slot , filled with diesel and shot down there. Problem sorted straight away,
It’s sometimes worth travelling if you can get a quick booking slot.
Try auto Electrical Services at Leighton buzzard they are truck electrical specialists but don’t know if they do motorhome stuff
 
Thanks for all your help. I have done some further digging and also had some helpful guidance from Ash@vanbitz. So I now know what and where the unit is.
It is indeed a Schaudt, model WA121545, rated variable 45 to 70 amp, currently set at 63amp, no pun intended.
As suggested by Ash the easiest solution is to replace like with like. He has pointed me at Apuljack Engineering near Bridgewater and they say it is repairable, so I am considering packing it up and sending it to them. They could also get a replacement.
I am still hesitant, with engine running all the expected indicators light up showing charging is working with no errors, but still no currently getting through to the battery as per the Votronic smart shunt.
Also yesterday, Lowdhams have offered to come and pick the van up,so they can diagnose and return it when resolved, but I fear that may take some while if they have to order in from Germany.
BTW the £1000 part they mentioned turns out to be a Fiat part, I know not what.
Hmmm
 
Sounds like a plan. Will you be able to claim back from Lowdhams/ Hymer?

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paddymcc said:
Sounds like a plan. Will you be able to claim back from Lowdhams/ Hymer?
Click to expand...
Yes, but only after they diagnose the fault as they won't take our word for it which is fair enough.
I will have fun removing the charger as Hymer have seen fit to place it in the double floor directly under the table mounting., 😭
 
Just thought I'd close this off as now resolved. I did send the unit to Appuljack for diagnosis, it wasn't that difficult to remove as it turned out.
Anyway they diagnosed it as beyond repair due to water ingress damage. That's a bit of a mystery, I am guessing the previous owner must have spilt something which went through the floor.... Maybe even washed the floor. It is snug dry in there now and all other electrical bits are undamaged.
To cut a longe story short, Lowdhams eventually tracked down a replacement and shipped it to me. I have plugged it all back together. On their advice, I have configured it to charge up to 70 amps. Working really well.
 
RobinE said:
Just thought I'd close this off as now resolved. I did send the unit to Appuljack for diagnosis, it wasn't that difficult to remove as it turned out.
Anyway they diagnosed it as beyond repair due to water ingress damage. That's a bit of a mystery, I am guessing the previous owner must have spilt something which went through the floor.... Maybe even washed the floor. It is snug dry in there now and all other electrical bits are undamaged.
To cut a longe story short, Lowdhams eventually tracked down a replacement and shipped it to me. I have plugged it all back together. On their advice, I have configured it to charge up to 70 amps. Working really well.
Click to expand...
Glad to see that you are sorted (y) and thanks for coming back with the end result. :) It may be of help to others with the same, or a similar problem and doing a search.

It is surprising the number of folks who seek the help of others, but don't come back with the end result. :(

Cheers,

Jock. :)
 

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