off grid lighting / shed lighting

[carpenter1]

could i power 12v tractor led work lights stright from a 12v battery, charged by solar panel?

 

if so how long for

say 10 x 15w worklights

 

and a battery with 8o ha

 

so how long will the light for?

[alex_m]

That will work. Fully charged it will last 6.5 hrs, that's without taking the panel into account. How many watts is the panel?

It would be worth getting a cheap solar charge controller to prevent damage to the battery.

 

 

Sent using Arbtalk mobile app

[doobin]

Something like this

 

led strip light | eBay

 

in cool white will give you a good spread of light with little shadow if wrapped around the room.

[openspaceman]

That will work. Fully charged it will last 6.5 hrs, that's without taking the panel into account. How many watts is the panel?

It would be worth getting a cheap solar charge controller to prevent damage to the battery.

 

 

If it's a lead acid batterry one needs to be wary of the depth of discharge, generally the deeper the discharge cycle the lower the life, e.g if you use 80% of its capacity it will have half the life compared with only discharging to 50% capacity.

 

"Leisure" batteries are designed differently from auto batteries which have high drains (starting) for short periods and are then constantly charged whilst the engine is running.

 

On the OPs figures 3hrs use would only use 50% of the capacity.

 

We use LED flo0ds for night use and these run for 8 hours but I have yet to see how long the batterry will last, I think it/s lithium ion, like in a laptop or cellphone.

[carpenter1]

If it's a lead acid batterry one needs to be wary of the depth of discharge, generally the deeper the discharge cycle the lower the life, e.g if you use 80% of its capacity it will have half the life compared with only discharging to 50% capacity.

 

"Leisure" batteries are designed differently from auto batteries which have high drains (starting) for short periods and are then constantly charged whilst the engine is running.

 

On the OPs figures 3hrs use would only use 50% of the capacity.

 

We use LED flo0ds for night use and these run for 8 hours but I have yet to see how long the batterry will last, I think it/s lithium ion, like in a laptop or cellphone.

 

what battery have you got?

 

i was going to use a leisure battery for the reason you said

 

any other recomendations

[JLA Arborists]

Get yourself a leisure battery and speak to a caravan dealer regards the solar panels outputs.

When were away, we have 6 fluorescents (foot long tubes) in the caravan on for about 5 hours a night. The battery lasts over a week without recharging.

If I had a solar panel I wouldn't worry about charging again. Also if I changed the fitted fluorescents for LEDs that would help the battery last longer.

[NFG]

Hello,

 

I have a reasonable amount of experience with battery discharging gained from the nuclear power program in the RN & also have a small off grid solar power system.

 

A few points:

 

1. As other posters have stated, battery selection is important & a battery capable of being deep discharged necessary. I use Rolls batteries they seem very good.

 

2. Your stated load of 10 * 15W is 150 Watts at a nominal 12V DC equates to a load of around 12.5 Amps. You need to look at the discharge curves for your battery to see how long the run time will be at this load (it is not linear). Your battery should NEVER be discharged below 10.5 volts below that voltage it becomes scrap metal - unfortunately below 10.5V it would not accept a full recharge & performance severely degraded.

 

3. Be aware that batteries are generally specified at the 20 hour rate, this means that the battery is discharge over a 20 hour period at a set discharge to 10.5 volts so for an 80 Amp/hr battery this would be approximately 4 Amps. Your load is around three times this so it would mean the battery would be fully discharged in around 6 hours or so. This of course assumes a fully charged battery 100% capacity.

 

4. If you deep discharge a battery 100% to 10.5 volts you will find it will provide a lot less cycles than if it were discharged to say 50% or less - Your manufacturer should be able to provide this info.

 

5. The next issue is will your solar panel re-charge the battery the next day?

 

I would say you probably need a couple of hundred watts of panel, I have 4 * 100w & they sometimes give around 28-30 Amps on a sunny day (in SW France) if that helps. Dull days a lot less.

 

If it were me wanting to run the lamps for a full six hours, I would probably select a 200 A/hr battery because it would not be fully discharged & last (in years of use) a lot longer than your 80 A/hr - all depends on how long you wish to run for really, if say, 2-3 hrs then 80A/hr would probably be fine at that load.

 

Hope this helps

 

N

[carpenter1]

it would only be for 3-4 hours 2 nights a week or so

[NFG]

it would only be for 3-4 hours 2 nights a week or so

 

OK

 

Your 80A/hr battery will be sufficient, although a 100 or 110A/hr would be better. If the intended use is 2 nights a week then plenty of opportunity to re-charge.

 

Try and equalise the battery once every couple of months or as per manufacturers recommendations.

 

N

[mendiplogs]

Something like this

 

led strip light | eBay

 

in cool white will give you a good spread of light with little shadow if wrapped around the room.

 

HI MATE thats what mum has in here log cabin led light far better on your battery thanks jon