20W LED powered by SLA battery..Help!

Hi,

I am attempting to build a underwater dive light consisting of a high powered 20W LED i bought off ebay. the specs are:

DC Forward Voltage (VF): 13.5 ~ 15.0 VDC
DC Forward Current (IF): 1500mA
Viewing Angle: 140 Degree
Color Temperature: 5000-7500K
Intensity Luminous (Iv): 1400-1600LM

I have attempted to power it using a 12v 9aH SLA battery and it works!..just one problem, it gets really hot quickly and even started smoking at one point. Is the problem the amount of current going into the LED and if so how can I reduce the intense heat? i've thought about fashioning a heat sink to go into the flashlight. the water will help dissipate some of the heat im sure but i have yet to find that out....any help would be greatly appreciated

Thanks!

Daniel

Your problem is that you are treating the led as just another (bulb) the led you bought says it's current rating is 1500mA you need get a driver that puts out 1500mA and no more. Does the seller of the led on ebay sell drivers for them as well? Also any highpower led needs a good heat sink, that 20watt one is not going to be very efficient and will require a large heat sink for it.

I've been helping another with his dive light. I suggest you read the entire thread before attempting a build. There's much better led's you can use that will be much brighter and better than that generic 20W you got.

http://www.candlepowerforums.com/vb/showthread.php?318980-What-batteries-to-power-a-24-volt-LED