Help with 18v mod - please

I am looking to run a light off my existing Ryobi 18v. It is an ok light as is but the bulbs are far too fragile for any sort of work use. An LED would be perfect for this, in my mind. I have a ton of batteries for this, so the life really does not need to be very long.

All I really need to know is how to calculate how many LEDs & resistors. Surely there is a simple formula to figure this, but I am having trouble finding it.

If anyone could steer me in the right direction, I would appreciate it.

There are some drivers that can handle 18v, so you don't have to waste a lot of energy on lowering the voltage. The drivers would lower the voltage to something the LEDs would accept(around 3.7v for each LED).

Presuming 1 LED, you would need a good heatsink that fits, the LED, thermal epoxy/glue, and a driver(soldering stuff would also be required). If you do more then one LED or don't have enough space, different reflectors/optic might also be needed.

How much do you want to spend?

Milkyspit might also be able to mod the light for you, but that would cost a bit.

You might be able to make something like this.

:welcome:

Given your battery voltage is higher than your LED(s), an efficient constant current regulator/converter that has multiple drive levels, I can recommend something that I have used several times before: the nFlex from Taskled:
http://www.taskled.com/nflex.html

Will

I did this with my ryobi a while back.
open the head and dremel out all the plastic
got a CPU heatsink and cut it so it round would fit in there pretty much - just tight enough to keep it in place.
4 x Cree XR-E Q5's in a star wired in series
1x Buckpuck 3023-d-n-1000
wire it up and it works great with NO optics - Very nice flood.

Works Great!!!

i'll get some pics for you

wow great responses thanks

mds would love to see those pics, please post. Does it get hot?

wquiles that page is over my head. If I had the nflex all I would need would be the leds right?

gunner, that link is exactly the sort of stuff I was looking for. thanks!

theprophet1966 said:

wquiles that page is over my head. If I had the nflex all I would need would be the leds right?

Click to expand...

You'll need the LEDs, heatsink, and optics/reflectors. You can skip the reflectors/optics if you want a pure flood light.

mds did you ever get a chance to take some pics?