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solar setup for my caravan

Posted: Sat Nov 26, 2011 11:46 pm
by mattbrown
hi everyone, me and my partner have just moved into a caravan and we have no mains electricity. we are currently using a 700watt generator that runs a battery charger that charges 2 batteries, the tv and a lamp. i would like to use some sort of solar panel setup or maybe a small wind turbine to keep the batteries topped up as i'm getting a 12v hd tv and apart from the laptops and phone chargers go completely 12v.

i know a little about solar panels and wind turbines but i dont know what options or kits to go for. the batteries i have are 85ah and 110ah but in a few months i'll be upgrading to two 250ah batteries, can anyone help me find a suitable setup to assist keeping the batteries topped up? we work during the day and dont leave anything switched on so there is no usage between 8 and 6 each day then the generator goes on from 6 till midnight but the batteries are never fully charged.

Re: solar setup for my caravan

Posted: Sun Nov 27, 2011 8:57 am
by solarwind
Greetings Mattbrown, and welcome. My wife and I and two sons spent 4 winters in a static caravan on a mountain in Snowdonia in the 90s whilst rebuilding a derelict cottage. I used a similar setup to the one you describe (generator, battery charger and batteries), and found that a large battery was required and a beefy charger capable of topping up the batteries within four hours or so. I built a 120A 12V charger and used a 1KW inverter. We eventually moved into the cottage and now our off grid power is supplied by 2 x 2KW wind turbines, 1.2KW solar array, a 540Ah @ 120v battery and 2 x 2KW sine wave inverters. The setup works well but wasn't cheap even though I did all the work myself. Best of luck with your adventure and don't forget "Look after the Watts and the Kilowatts will look after themselves"

Re: solar setup for my caravan

Posted: Sun Nov 27, 2011 11:18 am
by trappa
If y ou go into a maplins shop, the catalogue in there has loads of solar set-ups, and im sure you will find all you need there.
Maybe the website has it too?

Re: solar setup for my caravan

Posted: Sun Nov 27, 2011 9:58 pm
by mattbrown
hi solarwind and trappa many thanks for your helpful replies,

i dont mind running the generator to charging the batteries but the generator is smelly, its a suitcase generator but isnt very quiet and i find that even though i have 2 trickle chargers running on one battery and a large car battery charger on the other battery they never seem to fully charge. i have the generator running from around 6pm till midnight on weekdays and on and off all day weekends, running off it is the fridge, tv, 2 laptops a lamp and 2 battery chargers and the caravan onboard trickle charger. i run the fridge on the generator not on battery so it has a few hours in the evenings to cool the contents and during the day as noone is home the door is always closed to keep the cold air in. since i took the battery to a friends house and gave them a full days charge we havent suffered a flat battery yet.

in the field im in there are 4 other caravans and they all run generators as there is no mains electricity, the setup i'm looking to acheive would be to use solar or wind to top the batteries up during the day wile they are not in use so i dont need to run the generator every night especially in the snow. i have been thinking of housing the generator in a small dog kennel to keep the weather off it.

Re: solar setup for my caravan

Posted: Sun Nov 27, 2011 10:21 pm
by Zech
I'm sorry I can't help with generation, but I would ask: Are you sure you need a TV? We use a laptop for watching telly, which has surprisingly low power consumption. We haven't missed the bigger screen of our old telly at all, and many programs are available to download if you have an OK internet connection (which maybe you don't, in which case ignore me). I'm just thinking that the less power you use, the easier the problem of how to generate it. Maybe try doing without the new telly for a while and see how you get on (they'll probably be cheaper after Christmas anyway).

Re: solar setup for my caravan

Posted: Sun Nov 27, 2011 10:46 pm
by mattbrown
hi zech, ive only got the tv as its the one from the bedroom back at the house. i have a mobile internet stick that is ok but they impose limits sometimes if i use it a lot. i dont currently have an inverter so to use the laptops or the tv i need the generator running but with the money we are saving by not having the house we are looking to get a flatscreen tv that runs on 12v 24v or 240v. the main tv that we had at the house was a 60 inch full hd tv it was great in a large room but very pointless in a caravan.

Re: solar setup for my caravan

Posted: Sun Nov 27, 2011 10:54 pm
by solarwind
Hello Matt,

It seems under your current arrangements that you're charging your batteries at somewhere between 5 and 10 amps at 12 volts (you could check with a meter). If that's an accurate figure you'd be looking to replace it with 60 to 120 watts worth of solar or wind or both. I'd kick off with 200 to 400 watts worth of solar panels and see how you go, you might need more panels and possibly more batteries dependent on your consumption. As long as you're able to monitor your battery voltage you probably won't need a controller. Once you start to involve wind you'will.

Re: solar setup for my caravan

Posted: Sun Nov 27, 2011 11:10 pm
by mattbrown
one of my chargers is a 12v 750ma halfords trickle charger/maintainer the other charger is a halfords 1800cc upwards charger borrowed from my dad i'm unsure what the output of the onboard charger is. the batteries are 12v lorry batteries, at the minute i have the onboard charger running on one battery and the halfords trickle charger on the same battery and my dads charger on the second battery that is currently not being used. when i get chance i'll link the two batteries up but i'd like to get the charging set up first.

Re: solar setup for my caravan

Posted: Sun Nov 27, 2011 11:32 pm
by mattbrown
would you think a setup like the one below would be suitable?

http://www.ebay.co.uk/itm/400W-4x100W-S ... 2c5f4d1053

Re: solar setup for my caravan

Posted: Mon Nov 28, 2011 12:39 pm
by solarwind
Hello Matt,

Your charge rate is probably around 5 amps so 200 watts worth of solar is probably a good starting point. The grid tie inverter is of no use to you as it's designed to have a grid connection without which it won't work.