# wanted: portable floods



## Bushman5 (Jul 1, 2009)

asking for help here, because the most electronics i know is making jumper wires for my truck out of 0 gauge welding cable. 

I want a whole whack of those MCE leds mounted onto a big thick chunk of aluminum, which will be housed inside a small Pelican case. When you open the case, there will be a glass cover to protect the leds from water. (the glass will be sealed to the case). I basically want something like the Pelican RALS, but with MCE leds. I was thinking around 100 of them. 

power will be a couple of deep cycle batteries 12v , optimas or similar, 

is this possible? 

who could make it, cost, anyone in canada? :thinking:


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## AlecGold (Aug 18, 2009)

Everything is possible, but what will 100 good led cost?
And a pelicase is nice, but also a good insulator. With 100 led's it won't be easy keep the temperature down. A case with an aluminium piece on the outside, preferably with a lot of surface to get the temp down as much, would be needed. 
Price? high! a Cree P4 led costs 5 bucks if bought with 100 at a time. that is 500 bucks. Then you need a lot of aluminium as a heat sink. 
Then you need some big drivers, huge drivers (or an enormous amount of small drivers which would make it much more expensive). 
And the housing is a problem as well. 
A standard aluminium suitcase won't fit the bill, it is to thin and has not enough mass to dissipate the heath. 
Besides the mass of the aluminium you would need a lot of space to fit the converters, driving them straight could be done, but isn't really nice. 
I don't know any drivers that use 12V input and put out enough watt's for 10 or 15 leds, Xitaniums put out enough watt's for 6 leds and cost 21 dollar each, totaling to a whopping 350 bucks. So that would set you back a lot of space and they are used for 120V connections. 
I think if you want to do this right and make something nice you should look at a 1000 dollar investment in parts alone. 

Sensible thing to do is to buy a cheap electric power pack and some work lights and you're ready to go anywhere where there is petrol. my guess is that it is a lot cheaper and a lot more reliable. 
But sensible isn't the buzzword around this place


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## SFG2Lman (Aug 18, 2009)

you would never need 100 thats soooooo much light and power, you could prolly do 10 or 20 and be ecstatic with the results. It does sound like you want to build a closed system, the aluminum block is a good touch, but thats only going to slow down the heat up, the block needs to have maximum surface area exposed to open air (perhaps out the backside of the case) and a fan would really help (i think computer fans run on 12VDC) 

If you slightly underdrove each LED that would help TONs with the heat as well. You would lose some brightness but you would get a way longer run time and more stable lighting platform. If you wired the LEDs in series strings of three (maybe 4) and just made 5-10 of those strings all in parallel you may not need a driver as each LED would get about 3-4 volts and low amps depending on your battery. This would eliminate the need for drivers and more complicated wiring, either way good luck!


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## AlecGold (Aug 18, 2009)

I think 20 leds can give enormous amounts of lights, even when underdriven. 
But the waterproof case is still a problem if it isn't made from aluminium. 
BTW, a bit more aluminium can help to get a more even distribution of heat, which makes it easier to loose more heat. 

Direct drive is a posibility, but isn't really nice as the leds get weaker when the battery gets more and more empty. 
And with a 12V battery, you could make strings of 3 or 4. the number would depend on the hot-charge voltage: freshly charged batteries can get as high as 15 volt, so it could be wise to use 4 leds, have inititial a lot of light, after which it gets a bit less for a long time. 

20 leds would cast 130 dollars orso?

Then it is the housing that is going to pose the biggest challenge. Using computer-fans isn't helpfull in a pelicase (which is being used for the handy feature of being waterproof. (and strong) I guess.


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## SFG2Lman (Aug 18, 2009)

perhaps the pelicase should be split in half and install a stolid alumin half. Just undo the hinges and get an aluminum half? Cut some fins in the back of the aluminum and thermal epoxy the leds on the front? Personally I'd sacrifice water-proof to water-resistant if I knew it was going to keep the LEDs form burning out prematurely.


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