Flat battery

[bobski]

Question for you electrical experts,
I keep my motorhome in storage away from home so if I don't use the moho for a while I turn up to a flat engine battery. I think that the best idea is to have a separate solar panel connected to the engine battery to keep it topped up. My problem is, can I clip the solar panel to the battery whilst it is on the van?. The live terminal on the battery has quite a bunch of wiring so is it safe to connect to the live or do I have to disconnect the battery to charge it. It's a hell of a job to take the battery off so I want to avoid havi

 

[Jimbohorlicks]

Have you got solar panels on the roof already, if so you just need a battery master to connect your hab batteries to your starter battery, once the hab batteries are topped up they will allow a trickle charge to the starter battery, they are around £20 off e Bay.

 

[Kannon Fodda]

A few issues here

Firstly if the battery is allowed to go flat a few times, every probability it will become damaged and stop holding a decent charge, even after a good run. You may need to replace.

Secondly what is drawing power? Even alarm systems will used something, but otherwise turn everything possible off.

As for a solar charger, the question is going to be size. You need to be able to put into the battery at least as much as is being drawn off. In winter charging daylight hours are limited so your panel needs to keep up with that, and don't forget about cloud cover and even orientation. But you shouldn't need to unplug stuff. Simply connect the portable solar's croc clips to the terminals, or on some vans you'll have connection points under the bonnet if the battery itself is inaccessible.

As Jimbo says above if you have solar already get a battery master. I don't have that on my PVC but a switch let's me manually change between leisure or engine battery, but the battery master is on my to do list ....

 

[bobski]

Have you got solar panels on the roof already, if so you just need a battery master to connect your hab batteries to your starter battery, once the hab batteries are topped up they will allow a trickle charge to the starter battery, they are around £20 off e Bay.

Is is difficult to do?. im not very good with electrics. I have 3x 100 watt solar panels on the roof servicing the hab batteries and they are nearly always fully charged. The engine battery is new. i turn everything off when i leave the van so i have no idea what is taking the power.

 

[WESTY66]

Have you got solar panels on the roof already, if so you just need a battery master to connect your hab batteries to your starter battery, once the hab batteries are topped up they will allow a trickle charge to the starter battery, they are around £20 off e Bay.

I have a 100w solar panel on roof and I’m sure it tops both the leisure batteries and the cab battery, I don’t have a battery master that I’m aware of, just a red and black wire into the control box and two reds and two blacks out, I first thought it went to both leisure batts, but I’ve been told one set goes to hab and the other to cab??‍??‍ it was fitted by dealer when I bought it, I know nothing about motorhome electrics. Elddis Encore 255

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[MikeD]

dave newell lvs fitted the solar to my van and a portion of the output goes to the vehicle battery.

As my health has not been great recently the van has sat on the drive for a bit and it always starts ok and the leisure battery is alway fully charged.

I don't have a Battery master or anything like that.

 

[Jimbohorlicks]

Is is difficult to do?. im not very good with electrics. I have 3x 100 watt solar panels on the roof servicing the hab batteries and they are nearly always fully charged. The engine battery is new. i turn everything off when i leave the van so i have no idea what is taking the power.

It's not difficult, full instructions come with the kit. You just have to connect the battery master to the negative side of your hab battery and the positive side of the battery master to the starter battery, which may take some threading of a single core cable under your van to the starter battery. Just tie it to the wiring loom that runs under your van

 

[HandyAndy]

Remove your existing solar charge controller, replace it with a dual output charge controller. Swap all wires exactly as existing.
Then run a red and black cable from the second output to the cab battery. Done.
EASY.

 

[autorouter]

When fitting a Battery Master, the reason it suggests connecting to the Split Charge Relay is because that's where the starter battery positive, the leisure battery positive and a suitable negative are all together there in one convenient place.

However the split charge relay may be inaccessible or hard to find - for example, if your MH has a Schaudt Electroblock, the split charge relay is hidden inside. You can connect the Battery Master direct to the batteries, but this may require a longer wire unless both batteries are next to each other, as sometimes happens.

 

[HandyAndy]

The electrobloc has all the fat battery wires for both hab and cab directly terminated into the rear side of it. Easy to plumb into with one screw driver.

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[bobski]

Remove your existing solar charge controller, replace it with a dual output charge controller. Swap all wires exactly as existing.
Then run a red and black cable from the second output to the cab battery. Done.
EASY.

just ordered this. it will be the easiest option. thanks.

 

[autorouter]

I have 3x 100 watt solar panels on the roof

The solar controller spec says up to 240W of solar panels for 12V battery output. In typical North Europe weather your 300 watt panel array probably will rarely generate more than 20 amps anyway. Even if you did, the excess would simply be wasted. You may be wasting a few amps when the sun is at its brightest, but you will still get the benefit, in that it will generate more power when the sun is low or the weather is cloudy.

 

[Bluemanc100]

View attachment 344858just ordered this. it will be the easiest option. thanks.

I know this is an old thread but can anybody suggest a supplier for a twin core 4.0mm red and black cable to connect the second output on my solar panel controller to the MH (Van) battery? Ideally i’d like a 10m made up cable with the inline fuse holder and ring terminals for the battery.

I ordered a 5.0m cable from Photonic-Universe but when I route it under the bed and then under the chassis for simplicity the 5.0m isn’t long enough.. the supplier only does a 5.0m version sadly

 

[GeoffnDee]

I would suggest you have a look at sunstore.co.uk Worthing they carry this type of thing and supply kits etc for Motorhomes.

 

[Raul]

Failing that, have a look at “12v planet”.

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