Garage Lighting Project

[fliznora]

Hi, I am building a solar powered system for my garage so that I can see in the garage mainly for the winter when I come back from work late and it is late already..

I would only have the light on for five minutes or less a day. I already have a 7.2ah battery (a smallish lead acid) and a 11w 12v energy savinging light bulb, wire and switch.

My question is which size solar panel should i get? I was thinking 5-10w? And would I need a charge controller?

Thanks in advance..!

[Mike90250]

Hi, welcome.

Your 7.2 AH battery can only deliver 3.6 A (50% of capacity) without seriously shortening the life of the battery. 3.6A @ 12v = 43.2w so that leaves plenty of 10 min light cycles.
However, CFL's are not good at on-off cycles, 10 minutes, it will be just warmed up, and at full output. Perhaps a 10W halagon bulb, in an appropriate fixture, would work at all temperatures, give good light, and last a decent amount of time.

What will switch the light off and on?

I would go with a 10W panel, and you have to use a charge controller (that has a setting for your style of battery (GEL, AGM, or flooded) ) to prevent cooking the battery with overcharge.

[fliznora]

Hi, welcome.

Your 7.2 AH battery can only deliver 3.6 A (50% of capacity) without seriously shortening the life of the battery. 3.6A @ 12v = 43.2w so that leaves plenty of 10 min light cycles.
However, CFL's are not good at on-off cycles, 10 minutes, it will be just warmed up, and at full output. Perhaps a 10W halagon bulb, in an appropriate fixture, would work at all temperatures, give good light, and last a decent amount of time.

What will switch the light off and on?

I would go with a 10W panel, and you have to use a charge controller (that has a setting for your style of battery (GEL, AGM, or flooded) ) to prevent cooking the battery with overcharge.

Thanks for replying!

I will look into buying a 10w halogen if you think this would suit my needs better..

I will probably just use a normal light switch to turn the light on/off.

Ok 10w panel - no problem, sorry you've lost me with the GEL, AGM, or flooded battery question..(??) All I know is that its lead acid and it looks like it was from a remote control car or something like that..? Would something like this http://cgi.ebay.co.uk/ws/eBayISAPI.d...=STRK:MEWAX:IT be okay?

[4321loco]

If you need a 10 watt solar panel I may be able to help you?

Just let me know....

[leroy.wang]

20w/12v solar panel is better, UK winter irradiation is very weak, 2hrs is enough
and it can last for hours for your energy saving lamp

[Aussie Bob]

Hi, welcome.

Your 7.2 AH battery can only deliver 3.6 A (50% of capacity) without seriously shortening the life of the battery. 3.6A @ 12v = 43.2w so that leaves plenty of 10 min light cycles.
However, CFL's are not good at on-off cycles, 10 minutes, it will be just warmed up, and at full output. Perhaps a 10W halagon bulb, in an appropriate fixture, would work at all temperatures, give good light, and last a decent amount of time.

What will switch the light off and on?

I would go with a 10W panel, and you have to use a charge controller (that has a setting for your style of battery (GEL, AGM, or flooded) ) to prevent cooking the battery with overcharge.

I learn so much from reading Mike's posts.

[NaturalSolar]

Garage Lighting project

Hi,

I have a small set up using an old motorcycle battey, a camping style flourecent tube light (designed to clip to your car battery) and a small solar panel (again designed to top up your car battery). Works very well or the short times you need a light during the winter months. My solar panel sits in a window so is protected from the weather.