14500 battery from Fasttech-which one for SK68 clone

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 thermal pasted mine this past week.

The Sanyos are good batteries.

Grab the Nitecore. Don’t go anywhere near the xxxxfires. The Nitcore uses a Sanyo cell.

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.

http://www.fasttech.com/products/0/10000523/1084200-trustfire-14500-37v-900mah-protected-rechargeable-

Oh and they’re definitely brighter than with standard alkalines or Nimhs.

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?

Dunno. Some of the 68 clones specificaly state to not use 14500’s.

Thermal paste is cheap enought to try, but I really don’t know for sure about your shutdowns. Just a guess…Could be overloading the drivers.

Well then, the 14500 LiFePO4’s may be worth consideration.

Yeah flames are great in mine, anyone tried IMR? Any extra output?

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.

Trustfire Flames versus Nitecore, I was hoping to get a few more comments to push the balance to one or the other.

What about the 900mah versus 750 of the Nitecore?

LiFePos are brighter and simpler to use, cheaper as well… and are readily available locally…Home Depot has them.

Fasttech has 4 of those ranging from $2.14 to $4.71, any preference?

Since they are 3.2 volts and the Li lon are 3.6/3/7, why are the LifePos brighter, and are they safe to use in this light?

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

They are safer to use than Li-Co

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.

The light in question is a SK68 clone from ebay, and the original question was about which 14500 to use in it.

.

Nitecore seems to be getting some convincing praise.

All these batteries should be good for what, 5-7 years of light usage?

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.

PyTech - Sean :slight_smile:

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

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.