We are new to caravanning and will shortly be going "off grid" as I am informed at the Upton Blues fest. I was advised to get a folding solar panel to charge the leisure battery. Does anyone know what wattage of panel I should get.
Regards
PT56
It all depends on what you want to run from your battery. But I guess it should be 300 watts (Roof type)
Then again it also depends on what the weather throws at us.
If it is a folding one I think the highest you can get is 120 watts.
You will probably use about 220 watts per day with everything in use.
Our caravan came with a 40 watt solar panel as standard, fitted to the roof. It's main job though, which it does very well, is to keep the leisure battery at full charge while stored.
It has kept us going when on occasion the site's EHU trips, turning the fridge and heating to gas, but all the lights are led and we have no TV.
To live off it for any time would require significantly more, probably a couple of 120 watt panels (given that they produce less power on dull days).
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At present I have a 60W solar panel, which I slide onto the caravan roof, this provides 4AMP, in good sunlight. If I only have the main caravan circuits on, lights , water pump and limited tv, with a 12v satellite receiver, it just about keeps the battery topped up! fridge on gas. But with varying success, if its cloudy, the panel only runs at 50%.
However I have purchased over winter a 120W folding solar panel, to use in conjunction with the 60W, giving 180W and 8AMPS + 4Amp =12 Amps, which should be plenty to keep the battery full plus more TV hours. Our caravanning is a mix between on a field, so no power! to EHU.This next week will be the big switch-on, my wife can watch the soaps! and I can walk down to the local pub, and watch the football. Watch this space.
I have a 60 watt folding panel and we do a lot of rallying. We don't use a television when away but this time of year if the sun is reasonable the charge indicator will show the battery is fully charged frequently when away. We are going for 2 weeks holiday without EHU and this set up will be absolutely fine,
This an update on my thread, with regards to the solar panels I have in use.
I already had a 60W panel then purchased a folding type of 120 W, giving out about 12 AMP depending on the Sun?
They kept the 110 amp battery charged ok, but with the tele on for 3 hours, the battery suffered a bit, So I have another 110 Amp battery, of which I will couple up to the other, to give twice the storage capacity, hope fully the panels will keep the pair of them charged in day light, but giving more tele time at night, or at least 2-3 hours, plus keep the caravan circuits running as well.
In some respects the size of the panel is not as important as the efficiency of the regulator. A cheap regulator at 40% efficiency connected to 200 watt solar panels will give less power to the battery than a quality regulator and 100 watts of panel.
DaveCoaches, all I can go off is what my multi meter tells me. I f it says the 120 W solar panels are providing 8amp,in full sun, which is what the panels manufactures advertise, they do after the regulator, its good enough for me. You can only go off the manufactures recommendations. I am a engineer, I have found that what ever one says, and quotes from the recs, someone contradicts them. It is down to the purchaser, if satisfied with the goods ok.
All I am trying to say is that I spend quite a bit of caravan time off grid, my wife watches 2-3hrs tv, to keep the battery charged, tried different permutations, using solar panels. It seems the panels produce the power, daytime, but when tv is in use,night time, more battery storage is required, thus 2 110 Amp batteries linked up.Dont forget I am talking a few hundred quid of equipment here, to try and save readers on this link money experimenting.
My point is that it is easy to get confused by figures. People think that more watts is better. While this is true, if you skimp on a regulator, you can end up wasting a lot of the watts. If you are on a limited budget, and we are all limited to some extent, it would be a mistake to spend the entire budget on huge panels, then buy a £5 regulator which will waste most of the output from the panels. It is usually better to compromise on the panels a little so you have enough money left for a decent regulator. Regulators come in two basic types, PWM or the more expensive but more efficient MPPT. Some of the very cheap PWM regulators simply reduce voltage by converting the excess into heat.
Thanks Dave for the pointers, being new to all this I like to gather all information before deciding and you make some good observations, we are only going to use our van for long weekends and last time we used it for 4 Days the 45aH Car Battery (We have a 75aH Leisure one now) lasted but only use it for interior lights and water pump but didn't know about the different regulators.
We did start to look at 40W Panels but realised that for our needs we might only need a 5-10W Panel just to keep the battery topped up, nice to hear from personal experience as some retailers just want to sell you the most expensive system that you might not even need.
Amazing family weekend with old steam engines, classic car displays, market stalls, and full catering and bar. And camping on site - Save £25 by booking in advance.
Topic: Solar panels
Watch this space.
