This is the demonstration of powering 100W/34V  LED  from 12V power-supply .

there are 5 parts
1, 12V/7.4Ah UPS sealed lead acid battery

2, DC-DC step up converter [12v to 34V boost converter ]

3, constant current driver [ not include ]
   low cost LED driver from

4, LED 100w /34V with sufficient heat sink [ Processor heat sink  is a good option  ]

5,  LED Lens and Lens holder 

 video: old

video: new

SaurIMX5 months ago

Hi, i've tried to use a 50w led with the same driver you have. but the problem is whenever I try to power it with 12V supply, a hissing sound comes out and i only get 27V at the output with load and around 35V without load means without the LED. Is it normal or do I have a faulty driver?


I have had the same problem. I found that the gauge wire i was using was either too small or too long causing to great of a voltage drop through it ( from the battery to the boost converter). once the input voltage dropped to about 9-10v the converter would begin to hiss and the led would flicker. So check the input voltage to the converter at the converter and that should solve the problem.

crazypj made it!7 months ago

I thought I would check how flat the LED and heatsink were. They are terrible so I polished the back of LED with 400, 600, 1000 grit wetordry on a flat surface. It seems to reduced temps. I also used a copper heat spreader before the aluminium heatsink

100w LED 1.JPG100w LED 2.JPG
crazypj crazypj7 months ago

Oh, forgot to mention, the second pic is before I was finished removing scratches from 400 grit. The copper disc is a 'scrap' piece from motorcycle head gasket I made for my 1974 Honda. Copper has much better thermal conductivity than aluminium. I also used. thermal paste It used to be quite common to check the flatness of PC processors before fitting heatsink to get better heat transfer

Jestin_Cubetech (author)  crazypj7 months ago



great work.

reklrekl9 months ago
Nice thing.
But do i really need a current limiter to drive the LED and if yes, what transistors/resistors will I need?(32V, 3A) and do I need PNP or NPN transistors?
I think the step up converter is current limited at 6A, sso that would kill the LED...

Jestin_Cubetech (author)  reklrekl9 months ago

DC-DC 100W Constant Current Boost Step-up Module Power Supply.

ever check temps on that thing? id be curious as to how much light it actually produced and how warm it is 2-3" from the led edge and center.
Jestin_Cubetech (author)  pumpdatbass1 year ago
9000 Lumens.
at least 40 deg C
TheGreatS1 year ago
Very cool. Or rather, due to 100 watts, hot? Still, a great instructable.