I picked up one of those $2.50 SK68s from Ebay that someone brought to our attention a few weeks ago and I want to try a 14500 battery in it.
Fasttech has a Nitecore, a couple of Trustfires, and some other fires, which one of these should I choose, or should I go to another site for a different brand.
The TrustFire Flames from FastTech should do it for you. That’s what I’m using but mine are unprotected. However, you may want to put some thermal paste under the star of your SK68 before you run the hotter 14500’s. They didn’t come with any paste.
I have heard plenty of negative things about the xxxx-fire 18650s, but it seems people have a better opinion of the 14500s. I bought the basic flame ones from Fasttech and they work just fine in my 4 sipik sk68s and clones. I won’t touch a trustfire in a 18650, but I have had no problems with the 14500s. I estimate I get 30-40 minutes of output from the protected flames.
I assume the 14500s have a long shelf life as far as lasting for a few years?
Right now for the 18650 lights, I am using I am using some old Trustfire 2600s (blue) that are protected and that someone gave me, and that I had sitting around for about 3 years before I recently bought that Xin TD, they seem perfectly fine for the little use I give those lights.
I hope that the 14500s would be the same, that if I want to try a new light out and run it for 15 or 20 minutes in 3 or 4 or 5 years, that they would still be usable for that.
I have two sk68’s, one from T-Mart, one from a reputable Ebay seller. Both lights shut down very quickly (about 10 minutes ) using fully charged 14500 Protected Flames. Both cells charge up to 4.18v. I haven’t taken the lights apart to check for thermal paste, but I’m guessing there isn’t any. I wonder if this is a case were thermal paste under the star would increase the runtime?
My SK68 came from the ebay site which had been linked for this thread below, (the original post was edited and the link was removed when the price changed).
It seemed unanimous that the 14500 worked fine in it.
I have Trustfire, KeepPower, and Nightcore 14500's. Without a doubt, the Nitecore's I got from Fasttech are the best. They are the only one's I have the meet or exceed their mAh rating. The keepPower are inconsistent diameter wise. 2 out of the 4 I bought from KumberBear will not fit my Xeno E03 because they're too fat. The Trustfire's suck. They don't come anywhere near their rating BTW. I have 8 Trustfire's I got from Manifont and they all blow
For a single 18650 application, they will not be brighter unless your light can handle up to 7.2v at the upper end. If it does then you could use a couple of 123A LiFe cells which might make it brighter. LiFePO4 make my Spark SD52 run much brighter.
I got the Sanyo 14500 cells with the tabs. OK capacity, not great, and a lot of drop out (indicates high internal resistance) with a 1A load. I would not recommend them based on the ones I got. I also found this discharge graph from the FT discussion on that item. Closely matches what I got as well. ;(
I have TF Flames from DX that have better capacity and less dropout. I’m thinking of getting one or two of the Nitecore ones, pricey but sounds like a winner.
I’d say five years anyway, with maybe 20-30% capacity loss at the end. It does depend a little on usage, but a lot more on storage.
Store at a cool temperature (i.e. below 30C) with a resting voltage of 3.80V. Fully charged or at higher temps, they will degrade much faster.
Sounds like those batteries are dying very quickly, my TF flame 14500 batteries get at least 20-30 min on hi. You should start out with 2 fully charged batteries and as soon as the first one cuts out put the other charged battery in it to see if it’s a heat issue or battery issue, cuz the light is supposed to shut off when it drops to a certain voltage. Maybe you just got bad cells
