help wanted setting up a solar system in my campervan

Submitted: Tuesday, Aug 06, 2013 at 14:00
ThreadID: 103638 Views:2250 Replies:2 FollowUps:1
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hi guys, i have just converted my campervan to solar, i have installed 2x100 watt poly panels and 2x 110 leisure batterys, everything seems to be working fine,
but i am confused on my solar controller the are 3 sections. solar panel input.. feed to batterys.. and finaly a load output with a picture of a light bulb..i have my roof extracter fan connected to this, but for some reason it only goes live at night when the suns gone down and the led on the controller has gone off, very confused any help would be appreciated,
also the main reason i went down the solar route was to run my 3 way fridge on 12volt constantly when traveling i have a split charge relay that goes live when i start my engine one feed goes to the fridge and one feed goes to the campervan 12v controll unit, and when i stop the feed cuts.. how do i set it up so when my engine stops my solar and leisure batterys take over? also will my 2x100 watt panels and 2x 110 leisure batterys cope with running my fridge, it is an old eletrolux caravan 3 way fridge,
and finaly i have got a small 1000watt inverter when connected direct to the leisure batterys it wont work, but works ok when plugged into a cigerette socket being fed from my caravan distribution unit, most confusing..
thanks for looking
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Reply By: Member - Frank P (NSW) - Tuesday, Aug 06, 2013 at 15:48

Tuesday, Aug 06, 2013 at 15:48
G'day nutty,

With your extractor fan only operating at night ... many solar regulators have a programmable "night" function on the load output, where it can be programmed to come on at night to run a security light, etc. If you have an owners manual, see if you can re-program the regulator to do what you want.

3 way fridges typically draw about 10 to 15 amps when running on 12V. There aren't many small charging systems that can keep up with that, a vehicle alternator being one. You've done absolutely the right thing with your relay directing alternator output to the fridge while the engine is running. But there's no way a normal campervan battery/solar setup will keep up with runnning that fridge while camping. Maybe for an hour or so for a short stop for shopping or a lunch stop etc, but not for much longer. You should run it on gas or 240 for long stops and while camped up.

If your solar regulator is connected full time to your batteries, and your solar panels connected full time to your regulator, then your solar system should be charging your batteries whenever the sun shines. Your system would be in parallel with your alternator output when the engine is running - though it may be confused by the voltage provided by the alternator, but that's another matter. If it is wired as I just said, then when you stop your engine the solar should just continue to charge your leisure batteries and they should just take over. Are they not doing that now? Or have I missed something or misunderstood you?

It is possible your campervan control unit may be doing something you haven't told us about, so a bit more info might be in order. What is the control unit - brand?, what does it do?, is it a dc-dc charger? etc.

With regard to the inverter - check your direct to battery wiring. Good connections? Big enough gauge wire? Polarity correct? Have you used a pre-wired ciggy lighter? Some of those are cheap and nasty and may have a bad or broken connection. Is there an in-line fuse? If so is the fuse ok? Is the fuse-holder ok? No signs of being heated, distorted, or bad connections with the fuse?

Hope this helps, and give us some more info if you have it.



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Reply By: thenuttypuffer - Tuesday, Aug 06, 2013 at 16:28

Tuesday, Aug 06, 2013 at 16:28
righty ok i now understand about the light controller and i can set that to permanant live for the roof fan,
and yes you are spot on when i start the engine the solar controller turns off and kicks back in when i stop the engine,
my caravan control unit is a power management system pms3h there is no funtion on the pms3 to charge whilst driving only from 240v when hooked up, hence the seperate split relay.. you can choose between camper/drive batt or leisure batts, but i have disconected the camper feed as i have the split relay feeding the fridge through the pms and a seperate feed from the split relay direct to the leisure batts,
as for the inverter ive not a clue, all the terminals and cables are new and wired correctly, but il be dammed if i know why it wont work on the leisures directly, it works fine on the 12v feed that comes out of the pms into a cheap ciggy socket, most odd,
i was hoping with the 2 new leisure batterys and the 2 100 watt panels, i could run the fridge on 12v
it works fine when driving on 12v through the pms.
regards nutty :O)
AnswerID: 516008

Follow Up By: Member - Frank P (NSW) - Tuesday, Aug 06, 2013 at 17:13

Tuesday, Aug 06, 2013 at 17:13
"as for the inverter ive not a clue,"
Do you have a multimeter? If so, check for 12V at the input to your inverter and then check back, working your way back to the battery. At some point you should find 12V, so the fault will be downstream from there. That's all I can think of.

"i was hoping with the 2 new leisure batterys and the 2 100 watt panels, i could run the fridge on 12v"
Not a chance, mate. I had a 3 way in a caravan a while ago. I had it working perfectly on 12V with big cable hooked up via a relay to the vehicle alternator, but despite the full 12V it was getting under load it ran continuously. It's the nature of the beast to be inefficient in 12V mode. No solar assisted battery in a camper environment can keep up with that. You'll have to use gas or 240.


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