Caravan PV systems

[Plonker 3]

My other halfs father has a caravan which has a electric hook up and also a leisure battery which he can charge up and run appliances off it.

He has asked me about gettting a PV system fitted to charge the battery so he could then avoid paying for electric hook up.

Are these systems enough to give a decent charge to the battery during daylight (obviously depending on the weather etc) or would it just be false economy to have it fitted?

 

[Robotstar5]

A work colleague fitted a 1000x600mm (approx) panel to his caravan to charge the leisure battery. He only has to hook up if bad weather keeps them in the van running TV, playstation etc., he thinks it worthwhile doing.

It also keeps battery charged ready for weekend outings etc.

 

[john999uk]

Lots of panels in use on motorhomes. There is a shift in the type of panels in use. I am not up on the tech but something like the simple systems use 14v panels and regulators to keep batteries topped up. Usually about 80-100watts. There are some people using higher voltage panels (24/48v) and using a sort of switch mode regulator that is much more efficient.
If the caravan is fixed i.e. not a tourer then you can angle the panel to get the most power.
Bottom line is you need to know what his power requirements are. 'Leisure batteries' should not be discharged below 50% of capacity or their life will be reduced. You could also replace as many light fittings with 12v LED ones as very efficient and no voltage conversions to sap power. The real problem arises when you need 230vac as inverters are only about 80% efficient and use Lots of current. Think about things like hair-dryers, etc. very difficult with out 230vac. Also how does the heating work, does it require 230vac?
If he wants to go down the solar route then he needs to spend quite a bit on batteries and panels plus a bit on lighting, get a 12v tv (lots of LCD ones if you look are 12vdc).

 

[t4sltd]

Good advice from John 999uk. Suggest you buy a 12V or 24V panel and suitable charge regulator rather than a 30-35V panel (as used on houses) as it won't match the charge regulator.

 

[grantr37]

There's a lot of very good quality inverters on ebay (pure sinewave) which are put on by caravan shops as they are returned faulty, you can pick a 1500w one up for £30 and repair it yourself....otherwise new they are about £600 off the shelf( standard non sinewave that used a ramped square wave are about £120 - £150 for the same output) a non pure sinewave inverter will paste Laptop chargers and mobile phone chargers, so are only really suitable for Radios and small TV's...of low financial value...

if ventilation is good where they will go, or you can make/weld up some kind of bracket underneath for them, then I would say 2 Car Batteries with an Auto selector ....if you can be bothered then 1 large 12 Volt Truck Battery sat on the ground underneath and connected in, then packed up and moved would be a better option as they have more energy storage availability and power behind them...

New Truck battery will be about £160(if you buy the very best then about £600, but you are not running a lorry so I wouldn't bother)or you could try using a reconditioned one from a good scrappy- about £30, you can buy a bottle of electrolyte and a bottle of battery water for about £20 and pop in a few Granville Battery ...hang on I will go and look..... Granville "Bat Aid" Tablets...these look like small sterodents and come in a similar tube....these aid the Battery performance by keeping the Lead plates inside clean and free from Lead Sulphate...they are about £5.00 for a tube....using a Battery Lug fuse is a good idea as well....


type out a wall chart showing what combinations of things can be plugged in and how long each combination will take to drain the battery when off charge.....otherwise somebody will plug in 2 TV's a Toaster and a Hairdryer at the same time and paste the Battery...
I would fit 2 single sockets , one at each end of the caravan only wired to the inverter, label them as "Mains from Battery Inverter"


being able to charge the battery with a standard Battery charger from the mains on a changeover that swaps out the solar panel(s) would be handy for when heading off from site to site where mains might not be available later on.....