A mate of mine keeps his Caterham in a "Council" type garage that is part of a block of garages round the corner from his flat.
Trouble is the battery keeps going flat between drives and there is no mains electricity.
So I thought about mounting a trickle charger solar panel on panel above the door (luckily it faces south) and extending the wire inside to the
car.
So far so simple. But I was wondering if the trickle charger could charge a "spare" battery as well. From this I'd run a switch and a
couple of low energy 12v flourescent tubes, so you could see whats in the garage at night!
Anyone know how to wire this up so that 1 trickle charger keeps both batteries charged up, but that having the lights on only runs the spare battery
down, leaving the one on the car ready to go?
Cheers
Mike
They don't give a lot of charging current - enough to keep a well-charged battery topped up, but little more.
I don't think they'd charge a battery up from a discharged state...
http://www.maplin.co.uk/Search.aspx?criteria=solar&source=15&SD
=Y
Won't this do the trick? First result.
That's the one I've got - bought in Maplins on special offer ages ago.
we use them at work as a back up charging system for on board trailer batteries. As already said they will struggle to do the job mate. 2 off around
400mmX800mm certainly are not enough to charge a well flat battery. Sorry
However, they may well help to stop a fully charged and healthy battery from losing charge over time - which, in all fairness, is all they claim it will do.
I bought a generator cost £39 but I have recently seen em at car boot sales /markets for £35. This would enable you to use tools as well as lights.
The solar charger would then be perfect to keep your battery charged. 
I know of dozens of folks who used these solar panels to keep the battery topped up on boats (there was a BOGOF offer in some boaty magazine).
Consequently, there were dozens of these things littering the skip outside the boatyard. You need to keep the battery topped up for when the bilge
pump wants to play.
I tried one from Maplins a few years ago and it failed to overcome the current drawn from the digital clock on my car......
I use an inverter to power a couple of 5 foot lights from a12v battery which seem to last fairly well between charges. Jump pack for starting the car if needed. Perhaps he should use the car more often or get the battery and charging system checked? Painting the walls and fitting plaster board sheets help with the lighting
quote:
Originally posted by owelly
Consequently, there were dozens of these things littering the skip outside the boatyard.
LED lighting is the most energy efficient by a very large margin --- but you don't get much light.
quote:
LED lighting is the most energy efficient by a very large margin --- but you don't get much light.
I've looked into in the past and the solar panels don't make enough juice for anything other than topping up the car battery unles you're prepared to spend serious cash on panels....