Battery Master prep

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New to motorhomes, had a camper van before this.
Hi all

Van is an Elddis Autoquest 115.

I’m doing some digging around, basically screwing up courage to fit a Battery Master.

Under one of the sofas is a blue unit which I initially thought was the battery charger, but it turns out to be a battery to battery unit (Schaudt Booster WA 121525). Am I right in thinking this is a Good Thing, as it will whack a good chunk of charge into the leisure battery from the alternator?

Separately in the wardrobe, is a Truma solar charge controller, only connected to the leisure battery. Elddis wanted £230 to connect the van battery to the solar, I thought a better option was the battery master, as I can plug the van in at home or on a pitch and keep both batteries topped up even in the depths of winter.

So getting to the meat of it, is it ok to connect the battery master at the power distribution unit? The wiring diagram says that both leisure and van batteries connect into it, I’ll stick a multimeter onto the inputs to confirm. If this is a reasonable way to go about it, does it matter which negative I connect the battery master to, or do I need to find a separate ground connection for it?

cheers and sorry for the long ramble. Off to find the actual battery charger now. Must be in here somewhere...

Rob
 
What you suggest sounds spot on to me, -ve is -ve wherever you find it but connecting everything at on distribution unit makes it really neat and saves on cable runs.
 
It likely you will have a BCA power distribution unit, if you have then you mains battery charger is here under a panel on your power distribution unit.

1599320476080.png
 
So getting to the meat of it, is it ok to connect the battery master at the power distribution unit? The wiring diagram says that both leisure and van batteries connect into it, I’ll stick a multimeter onto the inputs to confirm. If this is a reasonable way to go about it, does it matter which negative I connect the battery master to, or do I need to find a separate ground connection for it?
Because the BatteryMaster amps is very low (about 1 amp) you don't have to worry about wire thicknesses and voltage drops like you would if connecting a B2B charger. So thin wires and connection to any negative point is fine.

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Thanks all for the quick replies.

Yes, it’s the BCA unit, which explains where the whirring is coming from in the evenings.

Reassured, tomorrow I shall become the Master of the Battery Master!

cheers,

Rob
 
So, that didn’t go as well as hoped.

I assumed there would be terminal block type connectors where all the wires go into the PDU. Nope - it’s all the modern car type multi plugs going onto a pcb.

Not to be deterred, I found the correct wires and checked them with a meter - leisure battery reading 13.6, I’m guessing I’m seeing the float from the solar here, and 12.5 on the van battery. So I still believe the battery master is the way forward, as the van’s only been parked up for a week and I don’t want the van battery dropping too much. Killed a battery on our camper van doing that!

So I tried the cut-in T connectors supplied with the battery master. These seemed to really struggle with the gauge of wire, I managed to get two in but the last one mangled both the connector and the wire.

I’ve ordered some more, but at this point, given that working under the sofa is painful to say the least, and the Elddis wiring is a rat’s nest I’m really tempted to book it in with Eddie and leave it to the experts.

Disheartened of Dudley

Rob
 
Oh dear, you said you had a B2B under there somewhere, what about the connections on that?
 
If you have completely or nearly cut a wire, you can join the cut ends with a 'butt connector'. Strip 3 or 4 mm of insulation off each end, insert into the butt connector. Use special crimping pliers to crimp the connector onto the exposed metal wire, then crimp the plastic insulation to give the wire some support.

In case you're not familiar with pre-insulated crimp connectors, they come in three colours, red, blue and yellow. These correspond to wire thicknesses: thin, medium and thick. You use special crimping pliers which have a colour-coded section for each type.

Since you have cut the wire, you could insert one of the BatteryMaster wires into the butt connector along with the original wire. If you have to use the next size up of butt connector, you may have to double over the other single wire to get it to crimp properly.

 
So are the in/out connections on the B2B from the two batteries? It also has a D+ connection, which I believe comes from the alternator, which made me think it was connected to the alternator rather then van battery.

Can I just connect the battery master across these terminals?

Thanks for the advice so far - hopefully this is fixable.

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So are the in/out connections on the B2B from the two batteries? It also has a D+ connection, which I believe comes from the alternator, which made me think it was connected to the alternator rather then van battery.

Can I just connect the battery master across these terminals?

Thanks for the advice so far - hopefully this is fixable.

Yes, basically, a B2B charger will have connection to both batteries and to an earth. Some (but not all) have a connection to the alternator to tell it when the engine is running. Others guess based on the engine battery voltage.
 
If it's a Sterling B2B it will have screw terminals, that you could add your BatteryMaster wires to. What model of B2B is it?
 
My CTEK B2B has a bolt arrangement but you need pretty large ring terminal crimps to connect to them (8mm IIRC).
 
It’s a Schaudt WA121525. It has a D+ from the alternator, which made me think it was getting a feed from the alternator rather than just connecting the two batteries.

I’ve found a wiring diagram for non-electoblock systems, which I think mine is as it has a battery charger sitting in the top of the distribution unit.

I’ll check the voltages at the B2B tomorrow, which should confirm it and assess the damage I’ve done to the wires in the cold light of day. May call in an auto electrician if I don’t feel confident with the repairs.

thanks to all for the help and advice - every day’s a schools day!

Cheers

Rob
 
I'm assuming here that your battery master didn't come from vanbitz?

The clue was the reference 'the cut-in T connectors supplied' - certainly not something I would ever use

The OP seems to have damaged the Moho's wiring by trying to use these connectors

Is there anyone on here local to the OP with the required knowledge who can pop over & assist/check?

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I'm assuming here that your battery master didn't come from vanbitz?

The clue was the reference 'the cut-in T connectors supplied' - certainly not something I would ever use
If you buy the VanBitz Battery Master for self installation it comes with the "T" connectors. They are in two sizes (different to appreciate if you just look at them) to reflect the size of the cable clamping into.

I can sympathise with the OP, having tried to install one in my PVC. When you do not know your way around the 12V systems of the van and leisure, identifying where you should connect the battery master is not an easy task. My van had the capability, via a manual switch, to divert solar charge from leisure to motor battery. I tapped into those cables for the battery master. It seemed to work. A few months later Vanbitz decided different when wiring up a B2B and lithium and the battery master moved.
 
Yes, it was from Vanbitz and it came with the T connectors. Only one size in the packet though, yellow ones.

I’ve ordered some more from Amazon, but I think to be honest I’m just going to get the wires checked/repaired and forget about it. Working on our old campervan was a lot easier and considerably less stressful!

Cheers

Rob
 
My understanding from reading up on the Schaudt and B2Bs in general is that they are in place of the old split charge relay system, and a lot better. So their function is to charge the leisure battery from the van battery when the engine is running. What they don’t do is charge the van battery from the leisure battery when on EHU or when the solar is topping up the leisure battery.

the Elddis manual also states that the van battery is not charged when on EHU, and they charge extra to connect the van battery to the solar charger.

Please someone correct me if I’m wrong, in which case I now have a Battery Master shaped door stop.

I’ll go out later and check the voltage on the van battery with the EHU connected, if they’re different then it would suggest the manual is correct and the battery charger is not charging the van battery.

Cheers,

Rob
 
My understanding from reading up on the Schaudt and B2Bs in general is that they are in place of the old split charge relay system, and a lot better. So their function is to charge the leisure battery from the van battery when the engine is running. What they don’t do is charge the van battery from the leisure battery when on EHU or when the solar is topping up the leisure battery.

the Elddis manual also states that the van battery is not charged when on EHU, and they charge extra to connect the van battery to the solar charger.

Please someone correct me if I’m wrong, in which case I now have a Battery Master shaped door stop.

I’ll go out later and check the voltage on the van battery with the EHU connected, if they’re different then it would suggest the manual is correct and the battery charger is not charging the van battery.

Cheers,

Rob
I think you are right the B2B will only charge when the engines running and is really to get more charge to the leisure battery the vehicle battery gets the higher charge anyway.
I thought about a battery master or the votronic equivalent but we're on hook-up at home now when parked up and it charges both batteries anyway.Wheen on-site we move every couple of days.
I like the wago connectors easy to fit and alter used them fitting our solar.
1599467231447.png

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My understanding from reading up on the Schaudt and B2Bs in general is that they are in place of the old split charge relay system, and a lot better. So their function is to charge the leisure battery from the van battery when the engine is running. What they don’t do is charge the van battery from the leisure battery when on EHU or when the solar is topping up the leisure battery.

the Elddis manual also states that the van battery is not charged when on EHU, and they charge extra to connect the van battery to the solar charger.

Please someone correct me if I’m wrong, in which case I now have a Battery Master shaped door stop.

I’ll go out later and check the voltage on the van battery with the EHU connected, if they’re different then it would suggest the manual is correct and the battery charger is not charging the van battery.

Cheers,

Rob
You are most likely right but even if the starter gets a charge from somewhere on hook-up or while driving it still won't do any harm fitting the Battery Master as if it isn't needed it won't do anything.

Martin
 
My understanding from reading up on the Schaudt and B2Bs in general is that they are in place of the old split charge relay system, and a lot better. So their function is to charge the leisure battery from the van battery when the engine is running. What they don’t do is charge the van battery from the leisure battery when on EHU or when the solar is topping up the leisure battery.
Yes, correct. The WA121525 has big screw terminals for the battery positive and negative connections. But the wires should be quite thick too, 10mm2 or 16mm2. If you can fit the BatteryMaster wires into the terminals that's the best way to do it. Make sure you do the screw terminals up nice and tight, they take a lot of current when the engine is running.
 
Thanks autorouter - I'll get the wires that I damaged checked/repaired first and let my stress levels drop a bit. Might ask Premier Towing whether they will fit it for me while they're doing the repairs - I don't bend anywhere near as much as I used to, and working under the sofa over the weekend has left me even less mobile than usual!

Cheers,

Rob
 

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