Boost driver(low-voltage) suggestion

Hello BLF. Relatively new flashaholic("Hi, my name is Jacob"), and first time poster :)..

I'm looking to make a single CR123(3V, non recharchable) flashlight in a P60 drop-in(using a WF-501A host), but almost all the drop-ins I've seen around the web use buck drivers(so as soon as the voltage on the battery drops a bit, it dies).

So I need a new boost driver for my drop-in(not entirely sure which LED I'll be using yet - propably an XM-L, but could be XP-G or XP-E), and I'd like some suggestions if you have any. Current-wise I'd like somewhere around 1.5 amps at 3.7V output. Modes aren't that important, but hi-mid-low would be first priority, singlemode second priority and last priority would be the silly 5+ mode drivers.

Fire away!

Hi Jacob and welcome to BLF.

This Solarforce drop in is pretty popular for use in the 501A

-XP-G, R5 320 Lumens claimed.

-Tight hotspot with the smooth reflector.

-Runs on .8 to 4.2volts.

-Pulls less than 1A on high with a CR123.

-$13 from Solarforce-Sales

-3 modes, high, medium and low no flashies

My favorite 501A drop in is this 5 mode XM-L drop in (converted to 3 mode)that I got from DX in a 504B host. It pulls 1.4 amps about 500 lumens on high and has a super low low setting which is perfect for the 501A. I run 16340 rechargeable so it might not be what you want since it goes into candle mode at about 2.8volts.

This drop in has a NANJG 101-AK driver that is easily converted to 3 mode with no flashy BS. This is now my favorite mini P60 drop-in not quite as bright as the Manafont drop in but you get a much lower low and a huge improvement in run time over the Manafont drop in I was using.

If you look at the picture on the chip on the bottom right you add a blob of solder to the bottom two right legs and you eliminate the flashy modes and get a nicely spaced three mode driver that is perfect for the 501A.

Thanks for the welcome E1320, and the long post to my problem.

The Solarforce dropin looks quite nice, and I am seriously considering buying that, but I already have a spare drop-in(actually it's the XM-L dropin from deal-extreme you are linking to), and I just need a driver that does boost(compared to the buck-driver already installed in the plugin). Do you know which driver the Solarforce use? It's something like that I need, except I would't mind if it was driven a bit higher.

I fell over a few boost drivers on DX, but somehow the quality just doesn't seem very appealing.

~700mA output judging from DX comments. Looks to be moddable by changing components, but efficiency drops quite a bit.

Quite nice specifications, even though I'd prefer a higher output. DX comments are mixed in regards to output and efficiency.

Pretty cheap, but comments talk of output currents around ~350-600mA.

All the boost converters on DX seem to have pretty low outputs and horrible efficiencies. Is this normal for boost converters, or just the DX batches? If I don't remember entirely wrong, the last time I made a boost converter in school(studying to be an EE) it had an efficiency around 85-90%. Of course, that was using components that would never even remotely fit in a flashlight.


I fell over this review: and it surely looks like something I could use for my flashlight, even though more current wouldn't hurt. Well, that and the fact that it isn't in stock.

Welcome to BLF!

I use this circuit board to resurrect an akoray. Works great both with 1,5 and 3,7 batteries. Output is about 1A, i don't remember the exact value.

Thanks!.. Always nice to get some personal reviews of products. I just ordered two of those circuit boards. Then I can try to mod one for higher current, and keep the other stock in case it goes wrong :). I also stumpled upon a pair of 16340 recharables, so I can compare performance(stock XM-L driver with 16340 and new DX driver with primary cells). This new flashlightcraze of mine is becoming a tad expensive I feel :).

Jacob I am not sure which driver the Solarforce uses, I do not have one. The only drivers I have bought are these from KD.

I only use rechargeable lion so they are perfect for me. They deliver 2.8 amps on high and are programmable, I have them all set to high, medium low with no strobes. I don't like the flashy strobe modes at all. Sorry I couldn't be more helpful.

Aloha and welcome to BLF Jacob!

Kig her:


Mange tak for velkomsten(and now switching to english), and thanks for the link - quite informative and definitely bookmarked. Unfortunately it confirmed my suspiction that I can't get any higher-output boost drivers without modding them myself.