B2B - again I'm afraid

David and Sally

David and Sally

Joined
Apr 9, 2018
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Worcestershire
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MH
Bailey Adamo 75-4t
Exp
March 2018
It's not too urgent as I can get the EHU put on for a few hours at a time on our permanent pitch. When I have visited - for essential grounds maintenance - I see that my leisure battery is being charged by the solar but not the starter battery. The starter battery is charged when on EHU as is the leisure.

If I want to solve this for the future I assume a B2B would do it, but I would not know how that affects the system with any conflicts between the mains charger (to both batteries) and solar charger (to the one battery) as they would all now be connected together.

Am I over-thinking this?

Thanks

.
 
Yes too complicated

Buy a regulator that charges the engine and the leisure batteries, but before you do, make sure that the regulator that you have doesn't do both and the installer has been lazy or incompetent and not bothered running a connection to the engine battery

Or fit a Battery Master
 
You want a battery master rather than a B2B, as stated by the expert ;)

As I understand it the battery master will trickle charge the starter battery when the leisure battery has a slightly higher voltage. So if your solar is doing the leisure once that is getting fuller but the starter isn't the trickle will start.

B2B diverts the alternator power splitting it more effectively to recharge both the starter battery but putting a much more effective amperage to the leisure when driving along.
 
eddievanbitz said:
Yes too complicated

Buy a regulator that charges the engine and the leisure batteries, but before you do, make sure that the regulator that you have doesn't do both and the installer has been lazy or incompetent and not bothered running a connection to the engine battery

Or fit a Battery Master
Click to expand...

My recently acquired Hymer E510 has a nice French solar controller. When I asked why it wasn't connected to both batteries the reply was "I didn't know you could!"
John

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I recently had a solar panel and B2B battery master fitted at Vanbitz.

My understanding is that the solar feeds the lesuire battery, and when there is a certain difference in volts between the lesuire and starter battery it feeds electric to the starter battery thus keeping it topped up.

the B2B blurb says a current can’t run back from the starter battery to the lesuire battery.

our cbe system also charges both batteries on EHU.

I trust vanbitz to have got it right, or told me of anything I should watch out for.

PS. Since having it all installed, van sat, not at our home, doing nothing except producing electricity ,!

so not able to see how it performs in real life ,( or that it even works, lol)
 
Thanks AXO66. So a master is basically connected in parallel to the EHU charger but they don't interfere with each other?
 
Or just buy a motorhome with it all on.....?
 
Just smiffy said:
Or just buy a motorhome with it all on.....?
Click to expand...
TBH I thought it did. '69 plate Burstner.

Not usually an issue as we have a permanent pitch with EHU and we always stay on sites with EHU.
It's only this situation we are in now.

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David and Sally said:
TBH I thought it did. '69 plate Burstner.

Not usually an issue as we have a permanent pitch with EHU and we always stay on sites with EHU.
It's only this situation we are in now.
Click to expand...
I have one for sale?
 
David and Sally said:
Thanks AXO66. So a master is basically connected in parallel to the EHU charger but they don't interfere with each other?
Click to expand...

I don’,t know, cos I am not up on the electric technicalities.

but i don‘t think it can add any additional current to the ECU Current as that would cause issues ., so presumably not in series in any way.

ours is just directly fixed to the positive feeds of both batteries and the negative of the lesuire. Its hidden away so I don’t know where it is yet , due to lockdown.

When I say positive feeds. I was shown at Vanbitz that It is attached to the positive battery side of the relays that chausson put into the circuits, so presumably the current flows as intended.

And a wire is attached directly to the negative terminal of the leisure battery .

It has to be fit fir purpose otherwise we would have heard about issues on these forums.
 
B2B is (usually) for charging the habitation battery quicker from the alternator.
If the starter battery is getting depleted (due to alarm/tracker) you gan join the habitation and starter batteries with a comparatively cheap unit (like a BatteryMaster) and it will keep the starter charged from the habitation battery. All you need to do, then, is keep the habitation battery up to scratch (EHU or solar).
You may not need a BatteryMaster device if that function is already be included in your supplied wiring. Check with your dealer (if you can).
 
I have fitted a Battery Master to our Inca, dead easy just three wires.

It means that where as before the solar would only keep the leisure battery topped up (without EHU), it now keeps both leisure and starter batteries fully charged all year round.

On our habitation Sargent Control Panel we have the option of charging one or the other batteries, but not both at the same time, the Battery Master bypasses this.
 
David and Sally said:
I'll pm later
Click to expand...
It comes with the motorhome though..?

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Hymer B544 2012 Comfortmatic

An excellent opportunity to acquire a well sought after motorhome with the layout and accessories for full time living or long periods away with all the facilities onboard for self sufficiency. Hymer B544 Left hand drive 3 berth 2012 6.5m long 2.35m wide 2.9m high. Fiat Ducato Maxi Al-ko...
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Just smiffy said:
It comes with the motorhome though..?

www.motorhomefun.co.uk

Hymer B544 2012 Comfortmatic

An excellent opportunity to acquire a well sought after motorhome with the layout and accessories for full time living or long periods away with all the facilities onboard for self sufficiency. Hymer B544 Left hand drive 3 berth 2012 6.5m long 2.35m wide 2.9m high. Fiat Ducato Maxi Al-ko...
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Click to expand...
How do you un-PM??? :LOL:
 
AXO66 said:
I recently had a solar panel and B2B battery master fitted at Vanbitz.

My understanding is that the solar feeds the lesuire battery, and when there is a certain difference in volts between the lesuire and starter battery it feeds electric to the starter battery thus keeping it topped up.

the B2B blurb says a current can’t run back from the starter battery to the lesuire battery.

our cbe system also charges both batteries on EHU.

I trust vanbitz to have got it right, or told me of anything I should watch out for.

PS. Since having it all installed, van sat, not at our home, doing nothing except producing electricity ,!

so not able to see how it performs in real life ,( or that it even works, lol)
Click to expand...
I think the CBE panel will already charge the starter battery once the leisure batteries have enough solar charge. The B2B will make sure that the leisure batteries get a better charge from the alternator when driving.
 
dunnah01 said:
I think the CBE panel will already charge the starter battery once the leisure batteries have enough solar charge. The B2B will make sure that the leisure batteries get a better charge from the alternator when driving.
Click to expand...

Our cbe panel does charge both batteries when the engine is switched on.
donkt know about what it does when solar connected to it?
this implies I might not have needed a battery master.(umm)


I’ve taken B2B to mean a battery master, not the gizmo which increases the speed the lesuire battery charges when driving. as the OP was concerned about the effect of being on ECU, so not driving ( i hope )

we had Battery master fitted with a solar panel as the same time as having a strikeback alarm fitted by Vanbitz , because always thought a solar would be useful, and because the alarm draws a current from the starter battery so needed to safeguard it’s cabability.

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Last edited:
dunnah01 said:
I think the CBE panel will already charge the starter battery once the leisure batteries have enough solar charge. The B2B will make sure that the leisure batteries get a better charge from the alternator when driving.
Click to expand...
I think a B2B is usually to allow a high charge from the alternator when driving they are a fair bit bigger and more expensive than a battery master.
A battery master is used to provide a low level of charge to the vehicle battery from the hab battery when the hab battery has a higher charge typically in storage when solar is producing charge but only to the hab battery.
Some solar chargers can do this without a battery master if they have 2 outputs
If you're on hook-up at home unless you sit on the same site without hook-up for ages when you're touring theres no worry anyway provided your vehicle battery charger feeds both batteries.

Am I right?
 
AXO66 said:
Our cbe panel does charge both batteries when the engine is switched on.
donkt know about what it does when solar connected to it?
this implies I might not have needed a battery master.(umm)
Click to expand...
Pretty sure Vanbitz know way more about the best setup than I do so if it's there it's there for a reason
 
David and Sally said:
Thanks @AXO66. So a master is basically connected in parallel to the EHU charger but they don't interfere with each other?
Click to expand...
All these devices - BatteryMaster, B2B, mains charger, solar controller - have a diode (electrical one-way valve) on their output, so there is no back-flow from one to the other. They don't interfere with each other.
 

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