Battery Master install like this (1 Viewer)

[Tombola]

I have 2 16mm cables feeding a b2b charger coming from the cab battery into the leisure/charging area, about 1 metre away.
I have ordered a battery master from eddievanbitz (funster code didnt work but hey ho)

Am I ok to install the battery master like the pic below? behind the B2B

 

[David and Sally]

Battery Master has two positives. One to LB, one to Starter battery. You seem to have missed out the BM to cab battery positive.

 

[Tombola]

thanks....of course DUH ! that would make sense, so like the below is fine? I dont have to take the cab batt wires right back to the battery?

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[David and Sally]

That’s it

 

[movan]

Tombola

 

[Robert Clark]

thanks....of course DUH ! that would make sense, so like the below is fine? I dont have to take the cab batt wires right back to the battery?

View attachment 469504

The battery master can be connected to both positives of the B2B charger
No need to connect to the leisure battery

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[Al n Val]

what is the battery master for guys n gals

 

[movan]

what is the battery master for guys n gals

When your leisure battery gets to a certain point it sends excess charge to your engine battery.

 

[Al n Val]

When your leisure battery gets to a certain point it sends excess charge to your engine battery.

so my Sargent unit does this so i don’t need one, is this correct

Al

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[movan]

so my Sargent unit does this so i don’t need one, is this correct

Al

I am sure someone more knowledgeable will be along shortly. Please don't go away.

funflair andy63

 

[sgl5gjr]

I've a CBE CSB2 does the same thing as the Battery Master....

 

[David and Sally]

The battery master can be connected to both positives of the B2B charger
No need to connect to the leisure battery

Yes. Depends hoe accessible all the connectors are. But that would be easiest.

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[ChrisL]

Can I just point out there should be some solar input or input from the hook up battery charger to the leisure batteries other wise the battery master will probably cut off once the leisure batteries get down to a certain level, I should say that I don't have a vanbitz battery master but my cheap one cuts off once the leisure battery gets down to about 12.7 volts I think.

 

[funflair]

I've a CBE CSB2 does the same thing as the Battery Master....

Well actually it might do the same for you but it works differently, the CBE CSB-2 needs a voltage threshold of 13.6 to send power to the starter battery this voltage might not be available from solar in the winter but OK on hook up. The VB battery master works on a voltage differential so can still keep your starter battery charged when the leisure battery is less than 13.6v, for example when our van is in the shed with no power the battery master will keep the starter battery tip-top from the LiFePO4 that sits at 13.2 ish volts.

Also my understanding is that battery master is the only device that will sit between LiFePO4 and lead acid.

 

[funflair]

The battery master can be connected to both positives of the B2B charger
No need to connect to the leisure battery

That depends Robert, on our MORELO the leisure +ve at the B2B is isolated once the trip is operated so if you want to isolate the leisure batteries but keep the starter voltage up you need to go the other side of the trip.

yes I made that mistake

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[andy63]

I am sure someone more knowledgeable will be along shortly. Please don't go away.

funflair andy63

You picked a right couple there joy.. but I see Martin has replied

 

[andy63]

Also my understanding is that battery master is the only device that will sit between LiFePO4 and lead acid.

Could you elaborate on that Martin.. what makes it the only one suitable..
I've got the Stirling unit that sits between lithium and lead acid.. I did ask Stirling and I got a shrug of the shoulders type reply asking me why not... I'm still debating if its OK as all these devices were designed with lead acid I'm mind..but so far
It's just active a good deal longer with the lithium voltage holding up a lot longer..
Andy

 

[Robert Clark]

MORELO made that mistake

That’s why I installed my own lithium, b2b, solar and battery masters

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[funflair]

Could you elaborate on that Martin.. what makes it the only one suitable..
I've got the Stirling unit that sits between lithium and lead acid.. I did ask Stirling and I got a shrug of the shoulders type reply asking me why not... I'm still debating if its OK as all these devices were designed with lead acid I'm mind..but so far
It's just active a good deal longer with the lithium voltage holding up a lot longer..
Andy

Not sure about Sterling Andy but Votronic and Buttner both say NO, and I don’t know why.

If that’s the battery maintainer it certainly doesn’t say anything about not using it with Lithium so assume all is good

Maybe I should have worded my initial response differently.

 

[Robert Clark]

Could you elaborate on that Martin.. what makes it the only one suitable..
I've got the Stirling unit that sits between lithium and lead acid.. I did ask Stirling and I got a shrug of the shoulders type reply asking me why not... I'm still debating if its OK as all these devices were designed with lead acid I'm mind..but so far
It's just active a good deal longer with the lithium voltage holding up a lot longer..
Andy

I had the Sterling one between lithium and lead acid batteries for years without issue

 

[andy63]

Not sure about Sterling Andy but Votronic and Buttner both say NO, and I don’t know why.

I'd love to know why.. they are simple enough devices..
It's just you said the battery master is ok between lithium and lead acid ..yet other than the voltage differential switching it does the same job as all the other devices
I'm thinking it does the lithium no harm to have a small load on them..
Andy

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[two]

I think that some compare the voltage at the leisure battery with that in the cab and only provide power to the cab battery when there is a certain voltage difference between them. If Lithiums have a lower voltage, they may never achieve the threshold required to start charging(?)

 

[Dave101]

Not sure about Sterling Andy but Votronic and Buttner both say NO, and I don’t know why.

The Votronic also works fine between LiFePo4 and lead acid, based on the same principal as the battery master, (0.7v difference across a diode) however it is a simpler device having no internal fusing nor any operation indicator.

 

[Robert Clark]

The Sterling b2b passes up to 3A which could be an advantage in some circumstances

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[funflair]

The Votronic also works fine between LiFePo4 and lead acid, based on the same principal as the battery master, (0.7v difference across a diode) however it is a simpler device having no internal fusing nor any operation indicator.

I thought Votronic specifically said not to use on LiFePO4, I also thought it worked on a voltage threshold.

 

[Dave101]

I thought Votronic specifically said not to use on LiFePO4, I also thought it worked on a voltage threshold.

Yes I know they do, but it work fine, it is the based on the same principal as the battery master, although it is only a 2 component device consisting of just a current limiting resistor and a diode, hence the 0.7 volt difference, no threshold measuring done at all.

 

[funflair]

Yes I know they do, it is the based on the same principal as the battery master, but the votronic is only a 2 component device consisting of just a current limiting resistor and a diode, hence the 0.7 volt difference, no threshold measuring done at all.

Every day is a school day

Do you know why they say not for Lithium to lead acid?

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[Dave101]

Do you know why they say not for Lithium to lead acid?

No I dont, I can only presume they think the standing fully charged voltage of Lifepo4 is to high at around 13.4v, but in my application with the van in covered storage it is probably better, drawing from the leisure battery sooner than it otherwise would and by the time the leisure battery is about 30% the starter battery is still at a safe level of about 50% . Normally I would never leave the van that long but with lockdown.... That all said, I do prefer the Vanbitz battery master simply because of the built in protections and operation led but funtionally they are similar.

 

[stmls]

Hi we have a solar panel and thought this was trickle charging our battery in the engine but it wasn't and every time we went to motorhome we were having to go to all the hassle of jump starting it in all weather wasn't good so we got battery master fitted from Phil at Rhino installs I think it was £99 and no more jump starting best £99 I have ever spent.