1V~3V 5-Mode Circuit Board for Flashlights (1xAA/2xAA/1x123A)

Pros: Works. Survived current being fed wrong way from incorrect battery polarity until it smoked.

Cons: Flickery low mode
Three strobe modes
Large size
Soldering/wires not overly robust

Other: This appears to be the only multi-mode driver for 2XAA but I would only buy this if it's absolutely necessary for a modification.

Pros: 5 Modes: High > Low > Slow Strobe > Fast Strobe > 8 sec Beacon

Cons: Not enuff mA and/or V output for CREE Q5s

Other: Find a better driver for Q5s, maybe sku.4735

Pros: Comes pre-assembled. After dealing with unassembled drivers this is a big plus.
Decent output and efficiency.
Can be used as a single-mode driver by removing the microcontroller board.
16mm diameter.

Cons: The microcontroller is the weak link in the chain, it's only benefit is to offer a (flickery) low mode. The strobe modes might be of some value to cyclists.
Power consumption is a little on the high side.

Other: Not a bad driver overall.

Pros: -As far as I know this is the only 16mm board here that can run a led with just 1x AA battery.
-After reading those other reviews I was a bit afraid about the brightness this would offer with just 1.2 volt input to Q3 Cree.. but after I had prepared for the worst, I was positively surprised on the brightness it offered. It really did make my Ultrafire C3 Q3 (sku.12093) usable again after it had it's board broken.
-No mode memory. I personally think that it's a "pro" that it resets back to high mode after being shut down for couple of seconds.

Cons: -Low mode does flicker a little bit, but it's hardly noticeable so it doesn't bother me much.

Other: I just got this, but the first impressions did leave a positive feeling for me :)

Pros: works with 1AA and 2AA
high and low modes, I don't need strobes

Cons: not very efficient, gets warm in the high mode

Other: the measurements are not proven

Pros: This is a cheap, decent boost driver for 2 NIxx/alkaline applications. It's a small size so it can fit in most spaces. It has 5 useful modes, not 20 crazy modes that nobody uses. If you want single mode, then it's easy to cut out the mode controller on top and connect the LED directly to the driver board using the well labeled L+ and L- points.
I removed the mode controller board on top since I only wanted a single mode for a flashlight upgrade. With 2D, here is what I measured:
Vin=2.6V Iin=1.4V Pin=3.64W
Vout=3.6V Iout=0.69A Pout=2.484W
efficiency = 68%

Cons: I wish efficiency was higher, but what can you expect for a dirt cheap boost converter?

Other: Overall an OK driver. It's good for 2-cell lights driving the LED at about 700ma.

Pros: - It's 16mm, not 17mm as most driver in DX
- As multiple modes
- Easy to install
- Works with 1 or 2 AA batteries
- I haven't noticed any flickering at the low settings (but I only used it for a few seconds, so maybe if you stay on low longer you'll notice the flickering)

Cons: - No mode memory
- The price could be a little lower. Other than that it's works great for the use I have.
- I would have prefered only Hi/med/low modes

Other: I needed a 16mm driver to replace a defective (the light took a fall from 2m) on a cheap (but with good output)light. This driver is perfect for that, and as a bonus now my flashlight as multiple modes.

Pros: gives enough mAh's for a step up converter quite cheap short mode memory- after about 3 seconds after turning off, it turns on again in first, HI mode, which is good in most cases

Cons: really weird modes- the ones I recieved last time was HI->really LO->strobe->blink every 7 seconds. The previous batch I ordered earlier had normal modes

Other: quite decent driver, if you don't mind weird modes- and you shouldn't- cause you don;t have to use them. regular user, not familiar with modes may not even notice it has any modes as the memory resets in a short time. The problem would be if it had long memory and switched to next mode every time turned on.

Pros: Worked like a charm! It fit perfectly into the project I had in mind for it. I used it with sku.03475 and sku.10084 for some very nice results running off of two AA batteries.

Cons: The price. I also didn't really like the 5-mode circuit. It fell off. I don't really see the point in the other 4 modes anyway. I can't see myself in a situation calling for varying degrees of a blinking light. If such a case occurred, it would be once in a lifetime, where I could just manually blink it.

Other: If you only need one circuit board and you want to use AA batteries, this is the one for you!