Advice required for Sterling BTB charger

[Richard Birkett]

I have a Sterling BB241235 charger fitted which is working well but we’re on site on EHU and every so often the BTB starts up and runs for a short while. If as It seems to me that the vehicle battery charger (CTEK MULTI XT 14000) is getting the vehicle battery up to a certain point wherein the BTB kicks in, is this okay or could I be harming the vehicle battery?
The BTB is wired as per their default setting but there is an option to incorporate an ignition feed, which means that the BTB is off.
Any advice greatly appreciated.
Richard

 

[nicholsong]

I cannot answer your detailed question about the interaction of the B2b, the CTEk and EHU.

We have an Elektroblok instead of a CTEK.

I was advised, including by Sterling, to keep the systems separate.

So, our Sterling B2B is wired from the Alternator directly to the engine battery and then the leisure batteries.

Works well for us. Only glitch is that Elektroblok ammeter goes to negative - Sterling cannot find a way to make the two system compatible, but I do not care as I know from the higher voltage that the B2B is banging charge into both sets of batteries.

So my B2B only works off the alternator. Why do you need it on EHU as the CTEK must be doing the job of charging both battery sets?

I suggest separating the two systems and only using the B2B when driving.

Geoff

 

[andy63]

I cant see any problem with that.. the battery to battery obviously thinks the alternator is running because of the high voltage on the engine battery... the only thing id be checking is what voltage its happening at.. i would have thought the charger would work within acceptable voltages and resort to a lower float charge when necessary..
If you try and start the vehicle with the batteries connected the leisure side may well be connected to the engine battery but shouldnt cause a problem as the engine battery is fully charged and shouldnt get a high current flow from the leisure batteries during starting...i dont have a battery to battery charger but guess that the ignition feed that you mention is to disconnect the b to b charger during starting..
See what others who have one fitted think..
Andy.

 

[Lenny HB]

Same thing happens with solar charging, if your B2B is the latest type you can set up to charge only when ignition is on there is a connection for this on the small terminal block, better still wire it to the D+ circuit from the alternator then it will only charge when the engine is running. Alternatively fit a relay inline with the output switched by the D+.

 

[pappajohn]

Why do you need a vehicle battery charger connected when you're using the van?
You should be able to last at least 2 or 3 weeks before you have problems starting...... Unless your starter battery is knackered.

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[Richard Birkett]

Thanks everyone for your advice & comments.
Perhaps I should have mentioned that the base vehicle batteries are 24v and therefore are not connected to the electoblok which deals with the 12v Hab side of things, which is why we have the CTEk 24v charger.
I will investigate the ignition link as per Lenny HB’s suggestion.
Pappajohn, I hope the above explains and no the batteries are fine (touch wood!)

Richard

 

[pappajohn]

If the cab battery is 24v and the hab battery is 12v what is the B2B charging.
To me its putting 24v into a 12v battery when the alternator is running... Or am I missing something.
I have no working experience of B2B.

Just realised, it's only across one of the cab batteries.

Still doesn't explain why you need a permanently connected 24v charger though.
If my starter battery starts getting flat I put it on charge for a while to top it up.

 

[Richard Birkett]

Pappajohn, I have no idea why Carthago installed the permanent 24v charger and now you’ve pointed it out, you are 100% correct, as none of my previous motorhomes had a dedicated vehicle charger. Perhaps it’s because the EBL performed that function when both systems are 12v? It all does seem a bit ott as I’ve got both 12 & 24v alternators. The Carthago handbook does make reference to their system ensuring that the vehicle is always ready to drive off. Perhaps a simple solution to the original problem/niggle could be to just switch off the CTEK!
Richard

 

[pappajohn]

It does appear at first sight to be a good idea as the CTEK will be a smart charger anyway and not harmful to the engine battery but at the same time it's interfering with other circuits which isn't a good thing.
I do like the idea of a dedicated 12v alternator though... Much more efficient than a split charge.

 

[nicholsong]

Stop asking us amateurs and just phone Sterling - one of the most knowledgeable companies in the business.

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[pappajohn]

Stop asking us amateurs and just phone Sterling - one of the most knowledgeable companies in the business.

There's nothing wrong with the Sterling B2B... Its doing exactly what it's supposed to do.
It's other charging systems causing the problem.

 

[Richard Birkett]

Stop asking us amateurs and just phone Sterling - one of the most knowledgeable companies in the business.

Where did that come from! Though Perhaps it wasn’t intended to be as rude as it appears.
As noted elsewhere, it isn’t the Sterling unit doing anything wrong (if wrong is the correct term) and I have found the amateurs on here to be extremely knowledgeable and helpful with the previous few times I have asked for help but thanks for your input.
Richard