Need 20mm driver with 3-mode, max @ 1A for XR-E P4, to work with 1x18650 and 3xAAA

The title almost says it all...

I have a DX C30 (flood to throw) XR-E P4 which I want to mod to be able to use 18650 as well as the current 3xAAA.

It doesn't have good heat management, so 1A for short time and 500-700mA most of the time, and also 100-200ma low mode, if possible. I don't care if there are also disco modes. Memory is nice but not necessary.

The driver must be 20mm (maybe I can manage with 19mm, but that's a long shot), otherwise I'll have to mod the flashlight body which I don't want to do. If there isn't a 20mm driver I'll just put a 1ohm or 2ohm 3W resistor and hope for good.

With easy to reach + and - soldering points, i.e. I prefer them to be on the perimeter and not at the center of the PCB.

Any suggestions for a driver?

Ebay has a lot of products, you can take some time to search


An easy solution for your driver woes is to use the existing bare pcb as a go between for your driver/battery. There is plenty of room in the pill for the 17mm driver of your choice. Just connect the +/- from the driver to the corresponding rings on the existing pcb (the thing that should be a driver).

Sleep is taking it's toll on my explanatory skills at the moment, so if you have any questions hit me up later.

Yup, after reading about drivers a bit, I understood that there aren't many good 20mm drivers, and I really have a hard time finding them.

I don't think there is a lot of room between the empty PCB and the emitter star, but I think I'll manage to squeeze the driver in between. I just hope the driver doesn't heat up in that closed space.

Maybe I'll try the resistor approach first, but I'd also like to try a driver.

So what 17mm driver is recommended? Easy soldering, 3 or 5 mode, current regulated (preferred) or high frequency PWM.

If I can recall correctly I've moded C30 with regular 17mm driver DX sku.7612. Removed blank "driver" and set new instead. No problems so far. It was my first mod and I give it away as a present, so can't check again. Would you mind checking diameter again?

I've made some measurements with photos.

I hope it helps.

Hmmm, I could swear I've put 17mm driver in it. It might be a bit different version. If I remember I can take a look at it in a few days when I'll go to visit my father who owns it now.

Thanks, ledoman, I would appreciate it.

Suddeny I have to go to visit my father place and I "stole" him a flashligh while he wasn't at home . I will return it with additional mod - no flushing modes with AK47 driver.

You were right, it's 20mm hole, but I've manage to insert 17mm driver in between dummy circuit and led star. See the pictures I've made in a hurry. Please note negative wire should hav contact with body at edge of a dummy circuit. Ask if you need something more. Have fun.....

Thanks, I'll try it soon!

Now I just have to pick up a nice little driver for me... :)

And wait a month for it to arrive. :/

Just note that the blank driver board has no contacts on the inside surface, whereas yours haggai has contacts internally. Just make sure that these dont short against the driver you put inside. Chances are it wont, but just be aware, and insuate where needed. Some tape, or a thin layer of epoxy, or something would help.

I'll buy some insulating (heat resistant?) tape as well.

Thanks for the advice!

But - won't the driver heat too much in the closed space?

AK47 is a fine driver. And you can select modes by soldering stars to ground. More you can find here somewhere on the BLF. What I would also suggest is to get rid of blank board as there is very little space. Try to find 1mm thick tiny alu, brass or coper ring/washer 20/17mm (cut from some pipeline or alike) and push along with the driver in a pill and you are done. No problems with space. Much better than my mod I would say.

The problem with that will be that the battery will push the driver towards the LED star, so I'll need to solder the ring to the driver and hope the soldering points won't separate... I think I'll also need to solder a small spring to the positive end (otherwise the battery won't touch the board), but I think I can manage that too.

I don't know if it is worth it, though, I'll start by just putting the driver like you did and see how it goes.

Not sure about other driver boards, but these AK47 drivers don't produce much heat.

How hard is it to solder the + wire?

Seems a bit crowdy at the center of the board...