# Battery Master



## granneb (May 27, 2008)

Good evening guys

With the summer coming to a rather swift end, I'm considering the fitting of a 'Battery Master' to get the engine battery thro' the cold months.

Problem 1. With little or no knowledge of the electrics of a modern vehicle, pretty good with Morris Minors, how difficult is it to install the said piece of equipment in the Ducatto?

Regards

Graham

PS What's happened to my England flag on the left?


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## DABurleigh (May 9, 2005)

If you have a conventionally wired split-charge relay and know where it is, you merely connect the 3 wires there.

Dave


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## granneb (May 27, 2008)

What is a 'conventionally wired split-charge relay' let alone where it is.

Graham


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## DABurleigh (May 9, 2005)

In which case most things in life are difficult with zero knowledge :-(

Damned difficult to wire a 13A plug if you don't know where it is! 

Dave


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## Chudders (Jul 5, 2008)

I have a Battery Master fitted but confess I got Van Bitz to install it for an extra £30 when I was staying at Cornish Farm, Taunton. However if you look on the Van Bitz website there is a wiring diagram.
Regards, Dave


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## Penquin (Oct 15, 2007)

I fitted one on our Kontiki and the wiring diagram is great, BUT locating the correct wires on the correct (split charge) relay is not so easy (or maybe it is just me!).

It works very well indeed and is a piece of kit I would strongly recommend - we leave a small solar panel charging both batteries via that over the winter and it worked brilliantly.

If I was wanting another I would get it fitted - VanBitz designed the thing and their service is excellent. You can stay on their site (really good and close to M5), and they will do it for you if you are in the SW.

No, I do not work for them!

Dave


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## CliveMott (Mar 10, 2008)

One wire connects to the fused Starter battery positive.
One wire connects to the fused Leisure battery positive.
One wire connects to chassis.

Thats three wires.

Or you could try a simpler solution requiring just 2 wires!

http://www.motts.org/BRIDGING FUSE.htm

C.


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## bikemad99 (Aug 17, 2006)

Could I please ask a question on this theme? I have a car to car charger for starting a car with a flat battery.You plug one end into the cigarette lighter of the flat battery & the other end into the lighter of the good battery. Would this charge the starter battery of the motorhome,if connected between the cigarette lighter in the cab & the leisure battery socket?I have my motorhome on hook up at home all the time.
Reg.


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## DABurleigh (May 9, 2005)

Graham,

Wiring diagram here:
http://www.campervanstuff.com/shop_stuff/Downloads/bat-masterInstruct.pdf

Straightforward, but if you want to avoid routing cables, you use the cables that are already there, and that's why the split-charge relay is the easiest place to fit it.

Dave


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## hogan (Oct 31, 2006)

Totally off topic
But this is a fantastic forum full of experts who are willing to give up time to help others.
Restores your faith to mankind.


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## Pudsey_Bear (Sep 25, 2008)

I really like Clives method, it makes lot's of sense, only thing puzzling me is why we would need the battery master, and spend more money than needed.

Answers on a postcard to............................

Kev.

PS, on top of Clives method, maybe a simple switch to turn off the supply to the fuse might be a good idea, placed next to the ignition switch.


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## Zebedee (Oct 3, 2007)

Hi Kev

You get one free if you buy a Strikeback through our great and revered leader's online store, and have it fitted by Eddie VanBitz.  

I would guess that's why a good few people have one - me included! :? 

Dave


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## Pudsey_Bear (Sep 25, 2008)

I can't afford prices like that Zeb.

However a fuse, a couple of lengths of wire, and a switch, is more my barrow.

Kev.


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## Penquin (Oct 15, 2007)

Clive's method is what I actually used - finding the correct wire on the correct relay was not so easy, but locating the places Clive mentions was straightforward.

As regards why have one fitted?

The vehicle battery always has some drains on it, e.g. clock, alarm system, even the digital display of mileage needs some power to keep it going. Thus there is always going to be a small drain on the vehicle battery.

The leisure battery is used for the habitation equipment. This is the prime charging destination if you connect the EHU, but it often requires a manual switching over to charge the vehicle battery (from my experience).

The battery master connects the two batteries safely so that current can only flow from the leisure to the vehicle and then only if the leisure battery has sufficiently high voltage to allow it to happen without flattening the leisure battery. Thus if the EHU (or a solar charger) is connected to the leisure battery then excess current above that needed for the leisure battery is diverted to the vehicle battery to keep it topped up. It cannot go the other way and therefore cannot drain the vehicle battery.

At least that is my understanding of the beast! I am sure that if I am incorrect someone will explain it better!

Since fitting ours our vehicle battery has stayed charged over-winter, with a small solar panel connected to the leisure battery and via the battery master to the vehicle battery - without having to switch the EHU on.

As a certain little furry animal would say "Simples!"

Dave


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## Pudsey_Bear (Sep 25, 2008)

Oddly I was just wondering if when I'm using the inverter quite hard and only having solar to charge up I might drain the engine battery, but I suppose I could fit a small LED light in the hab somewhere to warn me that it's still switched, actually it needs to be the other way around too, or am I confusing my self now, Wiring that should prove fun, Where's that Clive when you need him?

Kev.


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## granneb (May 27, 2008)

Kev_n_Liz said:


> I really like Clives method, it makes lot's of sense, only thing puzzling me is why we would need the battery master, and spend more money than needed.
> 
> Answers on a postcard to............................
> 
> ...


My thoughts as well, so where's the catch, apart from blowing a fuse or two.

Graham


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## Pudsey_Bear (Sep 25, 2008)

I know I'm going to regret asking this, but I've just re-read Clive brilliant solution, and wot he wrote was 

"Should one forget to move the fuse to the “park” position and start the engine, the fuse will blow. So carry a few spares!

I know I should know the answer, but the question is Why does it blow the fuse, it seems my befuddled brain is struggling today.

Kev

Yes again


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## short-stick (Jul 23, 2007)

I've got one of those battery master type thingys sat in my garage waiting for a buyer! I had it on my old van and it was very useful, but don't need it on my new van as theres a changeover option on the control panel.
Anyone want to make me an offer for it?
It's about a year old and mint.
Tony


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## DABurleigh (May 9, 2005)

It blows the fuse because the demand of the starter motor (hundreds of amps) is then taken from the leisure battery as well as the vehicle battey, through cables that aren't up to it, and for which reason the fuse is there 

Dave


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## 107558 (Oct 10, 2007)

As the VanBitz site is Under Construction does anyone know which colour wires go to which terminal?


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## Penquin (Oct 15, 2007)

JQL said:


> As the VanBitz site is Under Construction does anyone know which colour wires go to which terminal?


If you go to the Outdoor Bits website and then locate the Battery Master it includes a pdf of fitting instructions;

http://www.outdoorbits.com/Brochures/Battery_Master_Customer_instructions.pdf

you will find that very easy to follow (I hope)!

Dave


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## DABurleigh (May 9, 2005)

Yes, the same as I posted earlier in the thread 

Dave


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## Pudsey_Bear (Sep 25, 2008)

DABurleigh said:


> It blows the fuse because the demand of the starter motor (hundreds of amps) is then taken from the leisure battery as well as the vehicle battey, through cables that aren't up to it, and for which reason the fuse is there
> 
> Dave


thanks Dave, i went out just after posting my question, Then my brain woke up Duh Starter, big amps.

sometimes I frighten myself.   

kev.


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