Nigel M wrote:

I want to set up a 12v lighting system in a outbuilding, possibly with a
12v battery to be topped up by a solar cell. The system will need to
provide light for a 4m x 4m room, for an hour or so a day.

Anybody got any suggestions?

What level of light is required? Just enough to read by? Enough to do
detailed work? This can make a huge difference.

An 8W 12V fluorescent tube will provide enough light to see, but nowhere
near enough for say a workshop.


--
Grunff

Nigel M brought next idea :
I want to set up a 12v lighting system in a outbuilding, possibly with a
12v battery to be topped up by a solar cell. The system will need to
provide light for a 4m x 4m room, for an hour or so a day.

It really depends upon how much light you might need. You can buy 12v
light fittings as used in caravans and for camping, these are fairly
efficient consuming 8 to 12watts each. Alternatively you might consider
the 12v quartz lights with built in reflector, which are normally run
from a transformer in domestic situation. These can be obtained in
20watt and 50watt versions.

Obviously the higher the wattage used, the larger the battery would
need to be and the solar cell to recharge it. In addition you might
need a control on the charging system. For what an adequate solar cell
and battery would cost, you might find that running a mains supply
would be the cheaper option.

--


--

Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.org

On Wed, 13 Oct 2004 22:29:49 +0100, Harry Bloomfield wrote:

Nigel M brought next idea :
I want to set up a 12v lighting system in a outbuilding, possibly with a
12v battery to be topped up by a solar cell. The system will need to
provide light for a 4m x 4m room, for an hour or so a day.

It really depends upon how much light you might need. You can buy 12v
light fittings as used in caravans and for camping, these are fairly
efficient consuming 8 to 12watts each. Alternatively you might consider
the 12v quartz lights with built in reflector, which are normally run
from a transformer in domestic situation. These can be obtained in
20watt and 50watt versions.

Obviously the higher the wattage used, the larger the battery would
need to be and the solar cell to recharge it. In addition you might
need a control on the charging system. For what an adequate solar cell
and battery would cost, you might find that running a mains supply
would be the cheaper option.

--

Remember to vent the battery to the outside - you don't want a shed full of hydrogen.....

May be worth looking at one of those 'portable power' type devices, containing a battery and charger
that you occasionally see in cheapo shops, but remember that lead-acid batteries DO NOT like being
left flat for long, so you must remember to charge it regularly.
Solar would be ideal if you can get enough capacity at a sensible price. The sort of places that
supply to boatowneres would probably have everything you need, but at a price.
Surplus solar cells are sometimes findable cheaply.
Never forget ebay.co.uk as a possible source for this type of thing.....

"Nigel M" wrote in message
...
I want to set up a 12v lighting system in a outbuilding, possibly with a
12v battery to be topped up by a solar cell. The system will need to
provide light for a 4m x 4m room, for an hour or so a day.

Anybody got any suggestions?



I've done a similar thing in a rented council garage with no mains power. I
originally used 3x 50w 12v bulbs but these were pretty dim and drank power.
Current consumption was over 12 amps.

So, I swapped these out for cheap 20w CFL's (similar to 100w tungsten each
apparently) and used a cheap mains inverter from maplins to power them.
Result = far more light and far less power drain.
I modified the inverter to extend the on/off switch to an extrenal wall
mounted light switch. It's powered from a 65ah leisure battery and a solar
panel bought on ebay - can't remember power rating but about 1'x3' in size.
Panel is fitted to garage roof and system has been operational for over a
year so far with no problems. Inverter based lighting system has added
bounus of low current mains in garage for small tools or radio etc.

Alan.

In article ,
Alan wrote:
So, I swapped these out for cheap 20w CFL's (similar to 100w tungsten
each apparently) and used a cheap mains inverter from maplins to power
them.

That's an expensive and inefficient way to do it - unless you also make
use of the 230 volts generated for other purposes. 12 volt DC florries are
cheap and readily available.

--
*You can't have everything, where would you put it?

Dave Plowman London SW
To e-mail, change noise into sound.