off grid lighting / shed lighting

[Woodworks]

about 10 hours presuming an efficient invertor. But I don't think it is good for the lead acid batteries to be run right down. Think this is right. Amp hours x volts gives you watt hours

Edited December 1, 2013 by Woodworks

[carpenter1]

i keep finding that a 100ah battery will power 100w for 10 hours

so should easily run for 7 hours, not that i need that long

 

and the lights only cost £18

[carpenter1]

Varta Professional LFD90 - 90Ah Deep Cycle Leisure Battery

 

thinking of using something like this

[doobin]

These are very efficient. Once 5m strip turns the inside of a Transit van into day, scale that size up to your shed size? Major benefit is no shadow as the lights are all around.

 

12v LED STRIP LIGHT 3528 SMD 300 LEDS 5M UK | eBay

 

I used to use a compact fluorescent with a built in inverter that was very good but pricey. I think the LED strips have the edge, no shadow and for the same money as one of those bulbs you would buy 4 strips, that's a lot of light.

 

If you're going to go down the inverter route, I would get a decent battery set up and a small genny to run that would provide more power when required (angle grinding etc) and top up your battery. Running an inverter solely for lighting is wasteful and inefficient when there is plenty of decent 12v lighting on the market.

 

If it's solely light you want, a car battery would power them for a good while, then charge as you drove home. Two strips is 50w, at 12v that's 4.1 amps. A 60AH car battery could run those for 3 hours (using 12-13 AH) and it would be discharged to 80% capacity. That's a safe discharge level for a non lesiure lead acid battery. That would top up no worries as you drove home, or with a few minutes of engine idling. Install a digital volt meter into the system and it's foolproof.

 

How long will you need to run the lights for?

[alex_m]

That would do the job - i have two of the 225ah versions of these.

LUCAS 663 / 664 HEAVY DUTY | 12V 110ah Battery. Truck | Lorry | Leisure | Marine | eBay

 

I recommend lucas highly! 110ah and £20 cheaper than the one you posted.

[carpenter1]

These are very efficient. Once 5m strip turns the inside of a Transit van into day, scale that size up to your shed size? Major benefit is no shadow as the lights are all around.

 

12v LED STRIP LIGHT 3528 SMD 300 LEDS 5M UK | eBay

 

I used to use a compact fluorescent with a built in inverter that was very good but pricey. I think the LED strips have the edge, no shadow and for the same money as one of those bulbs you would buy 4 strips, that's a lot of light.

 

If you're going to go down the inverter route, I would get a decent battery set up and a small genny to run that would provide more power when required (angle grinding etc) and top up your battery. Running an inverter solely for lighting is wasteful and inefficient when there is plenty of decent 12v lighting on the market.

 

If it's solely light you want, a car battery would power them for a good while, then charge as you drove home. Two strips is 50w, at 12v that's 4.1 amps. A 60AH car battery could run those for 3 hours (using 12-13 AH) and it would be discharged to 80% capacity. That's a safe discharge level for a non lesiure lead acid battery. That would top up no worries as you drove home, or with a few minutes of engine idling. Install a digital volt meter into the system and it's foolproof.

 

How long will you need to run the lights for?

 

but how many metres would i need for a 30 foot x 30 foot shed?

[openspaceman]

Varta Professional LFD90 - 90Ah Deep Cycle Leisure Battery

 

thinking of using something like this

 

Spec says 200 cycles to 50% depth of discharge.

 

You want to pull 3 x 38W for up to 7 hours, that's 798Wh, your chosen battery has a capacity of 1080Wh to full discharge so you are likely to kill in within 200 days of use.

[alex_m]

But if you keep it charged so it isn't constantly going down below 50% then it'll last longer. Leisure batteries like being trickle charged constantly, rather than constant drain/charge/drain/charge.

[bobh]

That's odd I was always told it was the other way round, thought leisure batteries were designed to repeatedly be completely discharged and charged, but car batteries didn't like that and preferred to be trickled charged as they are by an engine.

[doobin]

No lead acid battery should be completely discharged. Approx 80% for a car battery and 50% for a deep cycle (lesiure) battery.

 

Carpenter- that's one hell of a shed! More of a barn! I'd buy a couple of strips to test the water- at £7 it's not gonna break the bank. If they're not man enough, buy more. Or buy something else and use the strips over the workbench for extra light. Either way you can't loose.

 

If I get round to it I'll take a photo of mine in the van.