Battery supplying lights??

[andrew692003]

Hi guyz, need some advice from someone who has a better knowledge of batteries and lighting.

I've been asked to do some voluntary work to supply some lighting to a few stalls for a craft fair. Here's the details!

There will be quite around 20 stalls spread out over around a 400m street. Generators and 240v supply's are out of the question.

Each stall will be set up individually and needs about 150w light. No sockets, heating etc. just lighting.

I can only think to use a battery set up but not sure on sizes or appropriate light fittings. I need a battery that will last around 10 hours. I've looked for 12v lights on the internet but can't find much in the way of DC fittings.

Any ideas?

Cheers

 

[andrew692003]

Sorry guyz bit of an update. As soon as I type 12 DC lights in to google I've found plenty :blush5:.

If I used 3 x 35w spots what size of battery would I need to power that for 10 hours?

Cheers

 

[Dunc]

35W/12V=2.92A so to run them for 10hrs you'll need a 29.2Ah battery. Multiply that by 20 and you're talking 583.4Ah, that's a chunky old battery! Thoughts about 12V LEDs? A 4W LED would be about the same as a 35W halogen and you would only need a battery capable of 66.7Ah for the whole lot. Obviously 20 batteries running at 3.4Ah would be better to make cable runs a sensible length/size considering the VD on a 12V supply would cause no end of problems.

 

[truckster]

35W/12V=2.92A so to run them for 10hrs you'll need a 29.2Ah battery. Multiply that by 20 and you're talking 583.4Ah, that's a chunky old battery! Thoughts about 12V LEDs? A 4W LED would be about the same as a 35W halogen and you would only need a battery capable of 66.7Ah for the whole lot. Obviously 20 batteries running at 3.4Ah would be better to make cable runs a sensible length/size considering the VD on a 12V supply would cause no end of problems.

Whos a clever boy then

As Dunc says divide up the batteries for shorter cable runs.

 

[andrew692003]

Cheers Dunc. I'm pretty poor with these calcs!

LEDs would work but I think 3 x 7w would be the way to go. Its has to be a battery per unit and they'll all be wired individually. The drivers are going to be a problem tho.

This is getting more costly and more problematic.

Cheers

 

[telectrix]

unless you can get inverters cheaply and use GU10 fit LEDs. that would save worrying about drivers. maybe divide the stalls into 5 groups of 4. 1 battery and inverter for 4 stalls

 

[Dunc]

Cheers Dunc. I'm pretty poor with these calcs!

LEDs would work but I think 3 x 7w would be the way to go. Its has to be a battery per unit and they'll all be wired individually. The drivers are going to be a problem tho.

This is getting more costly and more problematic.

Cheers

Why would you want drivers? Most MR16 LEDs are 12V DC rated.

 

[Dunc]

One of the wholesalers i use have just got in some TP24 MR16 LEDs, they're 2.5W and are atleast as bright as a 35W halogen. If you bought one at the handsome sum of £6+VAT and stuck it on a 12V battery for a few hours to check it worked you would hardly be breaking the bank.

 

[andrew692003]

Got it sorted. Cheap Draper inverter, 125ah battery and a couple of GU10 7w LEDs. I think I'll test it out first! ;-)

 

[Dunc]

Don't forget you'll need atleast an inverter capable of 420W for the whole lot or 2x400W set ups. Also the inverters will have losses on them due to the circuitry so in other words the battery might be dead before you expect.

 

[telectrix]

Got it sorted. Cheap Draper inverter, 125ah battery and a couple of GU10 7w LEDs. I think I'll test it out first! ;-)

sounds like a plan. you may find a leisure battery is better suited to your purpose than a bog standard car battery.

 

[HandySparks]

You could also take a look at 12V fluorescents used in caravans, etc
Googling brings up www.the12vshop.co.uk and loads of others. Might be as efficient as LEDs and give a better spread of light, if that's what you need.

 

[andrew692003]

Cheers guyz, some good advice there!!

I have a couple of months to try a few things out so I'm going to try MR16 LEDs and GU10 LEDs. I had also thought of 12v flo. lights to, I have couple that I was going to put in the van for winter so I'll try them aswell.

I actually didn't realise that MR16 LEDs were DC rated Dunc, I just assumed you still needed drivers for LV versions. Anyway I can pick up an inverter for around £30 (2000w) and I'll check for a battery to and let you know how I get on.

Thanks for the help, much appreciated.

 

[Geordie Spark]

I remember back in the 1950's when I was a lad my mum used to take me shopping to the market which was an outdoor affair with barrows & stalls etc.

In the winter time when evenings were dark, they used to be lit by Tilley Pressure Lamps which were run off paraffin. A modern version of these are camping lanterns which run on canisters of butane gas.

Maybe the cost of buying & running these would be less than buying batteries & electric lights?

 

[mogga]

why cant they use gennys ? lanark have "pop ups" in the street with rcds 4 comando sockets for when they have street fairs ect even got a couple of 32a ones for the catering people