Charging cab / engine battery from Solar panel.

[trevskoda]

This is a easy answer to your problem

Clive`s

Thats almost the way mine is only with a switch, mine uses h battery cable and 200ah relay, so in an emergency I can jump from less batts, but a simple thin wire will do as long as you switch off or pull the fuse before starting.

 

[Pudsey Bear]

Copy cat.

 

[trevskoda]

If you can charge via a dashboard solar panel through the cigarette lighter with ignition off, can't get much simpler than that. I don't like cigarette lighter sockets themselves (connection wise) so I'd probably wire into the back of it with an inline fuse and maybe a switch. Advantage of the cigarette lighter plug is it will likely have it's own glass cartridge fuse inside which you might wanna down rate to 5 amp.

Still require a regulator behind the cig socket, more expense which is not required.

 

[Drover]

Would not a split charge relay for solar be a easy option.
Kits are on ebay .. make sure you get one for solar

 

[barryd]

Would not a split charge relay for solar be a easy option.
Kits are on ebay .. make sure you get one for solar

Absolutely the solution should I decide to go down this route has to be a solar one. Im hardly ever on hookup. I think the battery master from Vanbitz that was offered does both. Vans going in on monday. Ill see what they say about the battery first.

 

[MERL]

I put the link on page one and some photos. Its this one https://www.mppsolar.com/v3/pcm20123012-series/

Yes there are various threads .outlets at the bottom of the MPPT Controller and I think there may be a spare two. Also a load socket which I run various 12v adaptors off.

Might be easier if I go and take some photos tomorrow or a video.

I didn't mean your solar controller Barry, I meant your main power distribution unit, the one with all the fuses etc.

 

[barryd]

That reminds me. I did take some photos earlier. Inside the wardrobe where the Solar controller is and the main board and charger etc and under the back seat next to the wardrobe where the AGM battery is located. Dont know if it helps. I dont think there are any spare slots underneath the MPPT controller.

 

[barryd]

Sorry. Those photos are totally crap.

 

[trevskoda]

Would not a split charge relay for solar be a easy option.
Kits are on ebay .. make sure you get one for solar

To do what.

 

[MERL]

Cant find any details on that PMS4 unit unfortunately, they seem like gold dust. So don't know if both the cab and the hab batteries are taken back to that unit or if there is a split charge relay somewhere, possibly under the bonnet where again, both battery connections are available.

 

[trevskoda]

So simple to run a wire and switch, cheap as chips and works 100%.

 

[wildebus]

Looking at the first photo of th control box, the switch bottom right selects between using the Vehicle and Leisure battery, or turning the system off.
Assuming this is connected (not all features may be connected in some installations, but on a factory motorhome let's assume they are), then THAT is 99% sure the ideal place to make a connedtion for a battery maintainer.
You bring out a connection from inside the box for both +ves of the batteries, which must be in the box (just need to follow the switch wires) to the maintainer; find an earth inside that unit (there WILL be one) and those 3 wires go to the maintainer and that is the job done.

Now THIS is an important point .... The above is only true IMO if you are going to use a proper battery maintainer such as the Battery Master or preferable the Ablemail AMT12-2. I would not do it this way if just using a switch connection or physical joining of the cable (the "clive Mott" type setup). The Wires you are using mayb be small and could not withstand the potential loading if you leave then connected when starting the vehicle. The Battery Maintainere by design are current limited and their draw will be within the design limits of the cables in the box.
Getting a maintainer will be more expensive than the 'direct' method but is very much a DIY job on the above. The alternative of running cables if employing someone to do it will cost more and give you a worse end result.

 

[wildebus]

Cant find any details on that PMS4 unit unfortunately, they seem like gold dust. So don't know if both the cab and the hab batteries are taken back to that unit or if there is a split charge relay somewhere,

possibly under the bonnet where again, both battery connections are available.

That reminds me .... On that age of British Motorhome, there is typically a pair of relays under the bonnet - one for split charge, one for fridge - with a D+ control signal. You could connect a maintainer there, spurring off either side of the relay. That would be literally a 10 minute job.

 

[Pudsey Bear]

found PMS3 if it helps

https://files.ekmcdn.com/olearys/resources/other/pms3-instructions.pdf

Bad pic of PMS4

 

[barryd]

Looking at the first photo of th control box, the switch bottom right selects between using the Vehicle and Leisure battery, or turning the system off.
Assuming this is connected (not all features may be connected in some installations, but on a factory motorhome let's assume they are), then THAT is 99% sure the ideal place to make a connedtion for a battery maintainer.
You bring out a connection from inside the box for both +ves of the batteries, which must be in the box (just need to follow the switch wires) to the maintainer; find an earth inside that unit (there WILL be one) and those 3 wires go to the maintainer and that is the job done.

Now THIS is an important point .... The above is only true IMO if you are going to use a proper battery maintainer such as the Battery Master or preferable the Ablemail AMT12-2. I would not do it this way if just using a switch connection or physical joining of the cable (the "clive Mott" type setup). The Wires you are using mayb be small and could not withstand the potential loading if you leave then connected when starting the vehicle. The Battery Maintainere by design are current limited and their draw will be within the design limits of the cables in the box.
Getting a maintainer will be more expensive than the 'direct' method but is very much a DIY job on the above. The alternative of running cables if employing someone to do it will cost more and give you a worse end result.

Well spotted. Yes that rocker switch does exactly that. Left is the leisure battery and right is the cab battery and it does indeed work so there is a connection.

I agree with you that if its going to be done its worth doing properly and I think I would prefer to employ a professional. I am cautious for two reasons. I dont like fixing stuff that maybe dont need fixing. It could turn out I have a duff battery but it could be that my style of motorhoming is responsible for slowly depleting that battery and the cause of my iffy starting problems. There is also the age of the van and its components. Am I going to get an engineer in who takes one look and starts scratching his head?

 

[MERL]

found PMS3 if it helps

https://files.ekmcdn.com/olearys/resources/other/pms3-instructions.pdf

Bad pic of PMS4

View attachment 118489

That's a pms3 Kev.
Don't know what the difference is?

 

[wildebus]

Well spotted. Yes that rocker switch does exactly that. Left is the leisure battery and right is the cab battery and it does indeed work so there is a connection.

I agree with you that if its going to be done its worth doing properly and I think I would prefer to employ a professional. I am cautious for two reasons. I dont like fixing stuff that maybe dont need fixing. It could turn out I have a duff battery but it could be that my style of motorhoming is responsible for slowly depleting that battery and the cause of my iffy starting problems. There is also the age of the van and its components. Am I going to get an engineer in who takes one look and starts scratching his head?

If you get someone who is familiar with campers - and especially conversions (your kind of system is obsolete in terms of what is fitted to new Motorhomes, but in principle is very typical of most self-build campers), then it should be a matter of the guy saying "no problem, guv" and sorted inside an hours callout.

 

[Pudsey Bear]

There must be a half decent auto sparky up there Barry.

That's a pms3 Kev.
Don't know what the difference is?

There is nothing out there for free.

It is terrible that even so long after the knowledge was really worth anything they still want to sell you the PDFs, info like this should be freely available to anyone who needs it.

 

[wildebus]

That's a pms3 Kev.
Don't know what the difference is?

Getting slightly off topic, but some photos which could possibly help get a feeling of what to expect when working on this PMS unit (TBH, I think if someone is wary, these photos will reinforce that, but don't be frightened!)

This is a PMS3H at the top of the photo (the H stands for Horizonal. There is a PMS3V as well (you can guess what the 'V' stands for )

1 - 1) Location for BMV by David, on Flickr

This is the rear of the PMS3H

PMS3H Rear by David, on Flickr

Now the point of showing this photo is that you can see that it is basically just a box and you have wires coming in and connected to a block.
That is where you get your feeds from. I can't tell you off-hand which connector is which as 1) this is a PMS3 not a PMS4, and 2) this was taken nearly 4 years ago when I was doing an upgrade on a VW Conversion.
I can't imagine a PMS4 will be that different to a PMS3 in the way wires are brought in.

Anyone who would come and look at the setup with a view to fitting a battery maintainer would be able to see very quickly which wires are which and certainly would not need access to a PDF in order to do so.

Now as far as maybe the issue is a duff battery? could well be, but evem if it is and you have to replace it, by fitting a battery maintainer you will be ensuring thw new battery gets maintained better when parked up and does't suffer the same fate. New or Old, maintaining batteries well is always a good idea and usually money well spent.

 

[barryd]

There must be a half decent auto sparky up there Barry.

There is nothing out there for free.

It is terrible that even so long after the knowledge was really worth anything they still want to sell you the PDFs, info like this should be freely available to anyone who needs it.

Its a nightmare up here Kev. Its like the place that time forgot. Ill ask my motorhome Fix it guy but he's crap with electrical stuff. He might know someone though. I think VanBitz are in Taunton. Their website says they will fit a battery master for £150 including the kit I think. Could even go that way again this year so that might be a possibility.