OK, just completed a discharge test, 582mAh. Here’s the graph:
Not terrible, I guess. Drops to 3.7V rather quick. I do not have a curve from another cell to compare, but I guess in an SK68 they would be bright for a little while. I still think there are better cells for a little more money.
Edit: Forgot to mention, for those who didn’t click on the product link; these are unprotected cells.
I didn’t write that comment very clearly, but I intended to say that the LiFePo is brighter than a AA.
I feel better using LiFePos in AA lights over Li-Ions because of the lesser voltage. I can substitute one LiFePo for 2-AA in an equitable swap, and the single AA lights I use them in don’t have an issue with the additional voltage. I do appreciate the brighter beam on the singles, those lights are marginal on AAs, and I am not trying to hotrod my AA lights, I just need them to work reliably when I need light to see.
I would not want to play around with any of my good lights either, like the Fenix lights, but my SK68 is not a primary light for me, and everyone says it is safe to use the 14500, it’s only value to me really is for goofing off with, and showing it to people and to keep by the thermostat or something, so the brightness is the real reason that I bought it.
Here’s a graph that compares the Sanyo UR14500L2 to the TrustFire Flame 14500 Protected (from DX). I had two TF cells, and I removed the protection PCB from one. The graph speaks for itself.
Sanyo capacities tested around 560 and 600 mAh.
TrustFire capacities were around 750mAh for both cells. The protection circuitry has a minor affect (about 50mV at the most) on the voltage during discharge.
For $1 more, the Trustfire cells easily outperform the Sanyos. I will reiterate that my TF cells were from DX. There is a chance that the Fasttech ones could produce different results.
Happy to see your graphs, Relic. I was going to recommend the trustfires as well as I've never had a lick of trouble from any except for the counterfeit pair I got from BIC a year ago. The ones from fasttech are great and genuine. I hate it when people bad mouth all xxxxfire cells. The genuine Trustfires are great in every size they make. It's the Ultrafire celks that are crap. This process they are better than the Sanyo 14500s.
Thanks guys, the flames are sure cheaper, I didn’t realize that the nitecore was for a single battery.
Would one of these 14500s and two dummy place holders be totally, 100% safe to use in a Saik SA-305, which is a 3AA flashlight?
By the way, the Saik uses one of those 3 battery holders, what if you just put the 14500 in it without the dummies, wouldn’t it still be the same voltage coming out of the battery holder?
Sound OK to me, I don’t have that light though. Usually 3xAA and 1x14500 are electrically interchangeable.
brad,
If that battery holder is the same as mine, then it appears that it places the cells in series for 4.5v total for NiMh(when they are just out of the charger that is). So using 1 cell would not give you the voltage. Two LiFePO4 cells and one dummy would give you 7.2v when the cells come off the charger. I use the 2+1 dummy configuration in my Spark SD73 because I know it can handle up to 7.6v, and that configuration lasts about 75% as long as the LSD NiMh cells and give me marginally brighter light. You’d have to check the spec’s of your light to see what maximum voltage it can handle, probably someone here knows, otherwise if the amount of light is not important the one LiFe would work.
I'd just run a 26650 if it would fit in the saik 305 .
J-mac I agree .....the Trustfire FLAMES are solid as a rock ..the other trustfires are garbage ..don't they make a trustfire 4000 or a 5000mah 18650 ??
Thank you for the kind words for the genuine Trustfire’s.
When people cast a broad brush across the names Ultrafire, Trustfire, Crapfire, etc it pizzes me off because they are NOT all the same.
I have had Zero defective Trustfire Flames in 14500,18650 and 26650 and I challenge anyone to beat the “bang for the buck” value that these cells provide.
I am talking readily available brand new cells, not laptop pulls or industrial packs torn apart.
Yes I have Sanyos, Keeppowers, and Panasonics and they are all fine cells. But they usually come at a higher price.
I like to have as many flashlights armed and ready as possible, so cost is a factor.
Make no mistake, If I am going to use a light that is an amp-hound, I will use the best battery available.
However a lot of lights that are still nice lights, do not need a high-end cell to perform to specifications.
Kinda like using high test gas in your Ford Focus, It may start easier but it ain’t gonna pull any harder or get better mileage, it will just lighten your wallet.
But then again, that may give you better mileage from the loss in weight 
Later,
Keith
Thanks to everyone for the Head’s up about the Trustfires, I hadn’t considered them before but I will now. Just to clarify, is the the Trusfire ‘Flames’ that are the ones to be looking for?
I have the same question, at fasttech the blue 14500 protected are a few pennies more than the flame 14500 protected, what is the difference?
I too has no issues whatsoever with TF Flames - both 18650 (2400mAh) and 14500 (750mAh). Those capacity numbers are always achieved.
The TF Flame 2400 from Fasttech even beat their unprotected Sanyo 2600 in both 1A discharge voltage AND capacity. That is even more impressive when considering the Flame does this despite being additionally burdened by the protection circuit.
BTW, I have both 14500 TF Flame from DX and FT and both I have tested to have around 750mAh capacity. That’s very good for the price.
http://www.fasttech.com/products/0/10000523/1084200-trustfire-14500-37v-900mah-protected-rechargeable-
http://dx.com/p/trustfire-protected-14500-3-7v-900mah-rechargeable-lithium-batteries-2-pack-26124
Yes you want the flames, the blue’s are probably more because they do not sell as many, volume = discount.
Thanks,
Keith
Are there any complaints about the Coolook placeholder cylinders?
Is there any difference between the black ones and the yellow ones?
I buy the yellow ones because they are easier to identify. I have noticed that in a few of my other devices such as AA Cell battery packs for my VHF radio they fit a bit loose. It makes me wonder if they may have a problem in avalanche beacons, I guess it would be a simple enough matter to shim them a bit if required. Have not had a problem in the lights with springs however, nor have I noticed any continuity problems so far. I just measured one and I get 49.75mm, so they appear to be .25mm shorter than stated. They say the black one is 50 as well, but I suspect they might be the same.
See post #1…I wouldn’t steeer ya wrong…. 
I would stay away from xxxfires Except for the TrustFire Flames from reputable source…i.e. FastTech.
I would definitely stick to only the Flames.
Fasttech just got these in today, are they better or worse than the flames do you think?
DLG 3.7V 14500 800mAh Lithium Battery
http://www.fasttech.com/products/1/10003877/1276310-dlg-37v-14500-800mah-lithium-battery-2-pack
DLG are Japanese made (IIRC) cells of high quality, they should be definitely better than TFF’s. But they’re unprotected.