Habitation battery to Engine battery link up..????? (1 Viewer)

old-mo

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Help please..

Went to move the motor home away from some tree`s to stop the leaves dropping on the roof.....

Battery flat again... :swear:

Now some time ago a very helpful Funster told me to link up the Engine battery and the habitation battery (Forgot who it was.. :doh:) Is this what I have to do ? =

Connect a wire from the positive side of the habitation battery to the Positive side of the Engine battery with an inline fuse..???

Then any excess power from the solar panel will keep the engine battery topped up... (I do not have a splitter or what ever it`s called.. The solar only keeps the habitation battery topped up.)

What gauge wire do I need and what size inline fuse is best, and will a Crocodile clip do to clamp on to the battery either end...

Going to route it through the drivers door handle to remind me to take it off before starting or driving away.. (y)

Thanks..

 

SandraL

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Yes, a 3 amp fuse will be fine if both batteries are charged to start with. Otherwise charged batt will try to charge discharged battery and could easily draw more than 3 amps. Small 3 amp fuse will blow if you try starting van, saving leisure battery and its skinny wiring.
Cable size reqd is minimal, you are only giving a trickle charge to starter battery.
 

Augusta08

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Well assuming you've got a 100w solar panel the maximum current it will provide is 8.3 amps. So a thin 14/0076 wire and a 10 amp fue would be fine. HOWEVER if the vehicle battery is flat and the habitation battery is fullthe initial current would be potentially enourmous!!!!!

Also you'll need to remove the link before attempting to start the vehicle, failure to do so would potentailly draw a hundred amps or more!!!

The current sharing is not rocket science but if you're not familiar with electrics it's best left to someone who is, you could easily save yourself £50 and cost yourself £1000's.

HTH

Gerry

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Abacist

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Mo - To save all that faff you need to get a Battery Master from @eddievanbitz which regulates the two batteries together ensuring that your cab battery never gets flat and you don't have to worry about any switches or connecting/disconnecting before using the van!
 
Aug 27, 2014
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I'd also be more inclined to fit a battery master or a batter maintainer:-

https://sterling-power.com/collecti...roducts/battery-to-battery-charger-maintainer

I've got the one on the link - works a treat, it connects to the hab batteries and trickle charges the starter battery if the hab batteries have enough charge. Fit & forget, save faffing about with a cable every time (and the risk of problems if you start the van with the cable still attached). Not to mention stops any risk of the charge rate problem Gerry describes above.
 
Aug 27, 2014
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CAK one is certainly a lot cheaper. Not sure what's inside it though - if it's just a voltage sensitive relay then I'm sure I remember reading they draw quite a lot of power to hold the relay shut - may be OK with mains hookup charging the leisure battery but not so much with the smaller solar setups.
 

andy63

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This is another little device that will help keep your engine battery topped... its most probably the cheapest of all the gadgets that can do this... they all have different cut in and out voltages and current rates, that give slightly different priorities but ive used this before and it was ok...
https://www.ebay.co.uk/p/Car-Batter...SB2-CBE-Accessories-Camper-Nautica/1679771620
Andy.

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Pugsy

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Hi i used this type.

Works well and i have had no problem.I do not have hook up only 12v on my van and this keeps the vehicle battery topped up from the solar and if needed it tops up the LB's when the engine is running.

A video link to show it being fitted. hope this is of some use.


Cheers Cris:cheers:.

Ps this is not my video its just one off youtube.
 
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old-mo

old-mo

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Eddie,,,,,, Does it come with idiot proof instructions on how to fix and fit..???

And does it just go between the battery`s?

Cos the unit in the wardrobe from the solar set up looks complicated what with all the wires and flashing lights.. :(

Although there are a couple of extra wire terminals, but would not want to play around with that/them...

Your`s truly..
Thicko old-Mo..

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Two on Tour

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It's 3 wires, battery to battery and the 3rd to a vehicle earth i.e. the chassis.
I connected ours to the hab battery, went through the floor, ran it to the front of the van to the cab battery and on our Elddis the hab earths have continuity to the chassis earth but I earthed our directly to the van chassis, job done, make a cuppa and tell Judy how clever you are. :LOL:

Here's the instructions for fitting.

BM.jpg
 

eddievanbitz

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The Battery Master is
100% waterproof
100% Vibration proof
Has internal re-settable fuses so can be connected up back to front and it will switch itself off
Simply operates when the Leisure battery is 0.75 VDC higher than the Engine battery, whether on mains, or a Solar panel is connected 1.1amp trickle charge

Best bought from Jim's shop http://shop.motorhomefun.co.uk/product/battery-master/
 
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old-mo

old-mo

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Thanks for all your reply`s.....

Totally confused now.... :doh: :giggler:

Below is a photo I have just taken of the unit in the wardrobe, which I assume is the solar panel control/distribution thingy..

I can see the red and black wire coming from the panel and a picture of a solar panel over it and another showing a number one battery which I also presume goes to the habitation battery...

There is another connection which is marked "No 2"...

Is this for another battery and could I run wires from this to the engine battery?

Or am I talking out of my backside and should just go for one of Eddie`s electric things..?

P1100965 (600 x 337).jpg

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eddievanbitz

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Thanks for all your reply`s.....

Totally confused now.... :doh: :giggler:

Below is a photo I have just taken of the unit in the wardrobe, which I assume is the solar panel control/distribution thingy..

I can see the red and black wire coming from the panel and a picture of a solar panel over it and another showing a number one battery which I also presume goes to the habitation battery...

There is another connection which is marked "No 2"...

Is this for another battery and could I run wires from this to the engine battery?

Or am I talking out of my backside and should just go for one of Eddie`s electric things..?

View attachment 264927
Yes you can simply connect the engine battery up and when it is sunny it will charge both batteries

Of course in the depth of a frozen Grey February where the Sun hasn't made an appearance for weeks it will do didly squat

However, you do shitloads for other people and for fundraising so email your name and address to me and I will arrange for one of Eddie's Electric things to be sent to you free of charge, as what goes round "should" come round

Eddie
 

hilldweller

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As per Eddies post #16

Eddie said his gadget protests itself he did not say it protects the wiring which it can't.

Buy and fit a fuse before the fire caused by that long thin wire connected to an 800A source shorting on the chassis.

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Two on Tour

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Thanks for all your reply`s.....

Totally confused now.... :doh: :giggler:

Below is a photo I have just taken of the unit in the wardrobe, which I assume is the solar panel control/distribution thingy..

I can see the red and black wire coming from the panel and a picture of a solar panel over it and another showing a number one battery which I also presume goes to the habitation battery...

There is another connection which is marked "No 2"...

Is this for another battery and could I run wires from this to the engine battery?

Or am I talking out of my backside and should just go for one of Eddie`s electric things..?

View attachment 264927


Forget about your solar controller, no connections to it needed, only direct connects between the hab and cab batteries and the vans earth.
 
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Can not remember what make your MoHo is @old-mo, but seem to recall when we stayed over with you that it is a newish model. Are you sure that it does not already have fitted the necessary kit to split the incoming charge from the solar panel to both the Engine and Leisure Batteries?

If the Solar panel was a retrofit by the supplying dealer, for ease of fitting (or idleness), it may have been wired from the solar panel regulator (hopefully via an in-line fuse) directly to the terminals of the leisure battery. Mine was and without a fuse!!!!!! I rewired it (replacing the regulator for an MPPT model – worth doing at the same time to maximise output from the solar panel) to the Sargent Control Box, using a lead (with the necessary plug for the control box pre-fitted) supplied with instructions from Sargent.

If you do not have the necessary kit already installed and do not wish to go to the trouble of any re-wiring, a cheap an easy alternative could be to plug in a solar-powered car battery charger, which just sits inside on the dashboard (and could be transferred to a car when you are away in the MoHo for an extended period). I have one for the car and chose an “AA Solar-Powered Car Battery Charge”, currently available from Amazon for £22.80 with free delivery. This is shipped with two leads - one for the usual 12v cigarette lighter socket and one for plugging into the OBD port. On most modern vehicles the 12v sockets are turned off with the ignition and can therefore not be used for charging in this way. I have been using this solar panel plugged directly into the OBD port for several months at a time over the last year. This has been without problem and with starting first time on our return. No problem with needing to know which OBD pins to use. The +ve and -ve pins are standard and the OBD lead supplied (with the kit mentioned) just plugs straight in. Have never measured the current, but the following video clip suggests about 7 mAmp in bright sunshine. This is so small that a regulator is not needed and is really only intended to make up for the small drain caused by the onboard electronics which remain on when the ignition is turned off.

https://www.youtube.com/watch?v=4hxiI4dBu24

Hope you get it sorted, whatever you decide.

.
 

Two on Tour

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Eddie said his gadget protests itself he did not say it protects the wiring which it can't.

Buy and fit a fuse before the fire.

@eddievanbitz can you clarify this for him please.

Edit : Sorry Brian not being rude, him has a name.

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Last edited:
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old-mo

old-mo

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email your name and address to me and I will arrange for one of Eddie's Electric things to be sent to you free of charge, as what goes round "should" come round

Eddie

I am lost for word`s....

Just totally gobsmacked by your offer...

Bought a lump to my throat and cannot Thank You enough.. :hugs:

:ta:
 

eddievanbitz

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Where the Battery Master is connected to an existing fused supply, the three 6mm studs in this picture for example, no additional fuse is required. If the Original wires are to be extended or a new supply is being added than a fuse would be required. However, virtually every motorhome has a split charge system which is "A" already correctly fused "B" normally a great place to connect the Battery Master
BM.jpg
 
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old-mo

old-mo

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Can not remember what make your MoHo is @old-mo, but seem to recall when we stayed over with you that it is a newish model. Are you sure that it does not already have fitted the necessary kit to split the incoming charge from the solar panel to both the Engine and Leisure Batteries?

Don`t think it has anything other than the solar to charge the hab battery..

So going down the superb offer of Eddie`s, which even I should be able to install... (y)

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