JUNK TF 10440's

I bought the grey Trustfire 10440's from DX and just got them in over a week ago. Three showed up completely drained, showing 0.0V, which I thought was weird. But they are such a small capacity, I figured maybe this was something normal?

Well as I was doing some current tests with my F-23, I found these things to be ALL OVER THE PLACE. Again, this was with a brand new F23 host, all 4 charged with a TR-001 around a week ago.


They had all self-discharged at quite a different rate in just several days, and their performance was astounding! The worst cell produced barely half of the best cell? I understand they are the same price as a LI-PRI at Wal-Mart, but I expected a little more than this.

SOOOOOOOOOOOOOO, which 10440's should I buy this go'round?

Apparently the blue ones are better. I think Don tested them?

Im kinda new still to flashlights and about a week or so back i asked for suggestions of lights i should buy. Many suggestions were for AAA single cell lights. For those it meant id be buying 1.7v Lithium primaries which are expensive throw aways and of course the 10440 rechargeable.

I found that very few makers even have a 10440 in their line-ups and if they do the specs are made up and usually 2x their real capacity. 350mAH true power seemed to be the norm in world where most were over-stated at 500mAH - 600mAH. What tests i found were like yours and very inconsistent.

I said to myself it wasn't worth it to use 10440 cells in a single cell light, Nor was a AAA effective power wise or price wise. Id stick with AA and 14500, And even with them the results haven't been as good as stated. But i have more tests to run on these cells.

The blue ones are no longer available on DX. Maybe try the grey ultrafires, since they at least a different label on the outside. :)

I suspect you have some measurement error, as the numbers don't make any sense... Depending on the light, either a higher voltage increases current, or a higher voltage decreases current, but not both - if your light draws .68A at 4.03V and 1.1A at 4.06V, either something is very wrong with the driver in the light, or something went wrong measuring - loose leads or the like.

Also, keep in mind 1.1A is almost 4C (actual capacity on the cells is only 300-350mah), a lot more than you should draw from those cells for any length of time.

I don't know of any better 10440s - the IMR ones are fake (exact same capacity and internal resistance as a lico, so just a different sticker on the same cells), and I think the TF and UF are the same cell with different labels, as none of the comparisons I've seen show much difference. I'd suggest cycling them a few times, then performing some more accurate tests to see if they're really the cause of the problem or not.


I will cycle the batts a few times and report back. My meter seemed to do well all night while testing many other lights with every kind of battery I have. Nothing out of the ordinary aside from these little guys.

But unless your "watts" columns are done by multiplying the no-load voltage by the load current, something didn't work right. :)


That's what I did, I believe? Just to measure/compare cell performance. Is that an incorrect way to measuring power to the driver?


Yes. Voltage drops under load compared to no load, in some cases substantially. If you want to compare the cells fairly you need to start at the exact same no load voltage (or as close as is possible) to remove that variable.

In order to measure watts, you need to measure the voltage at the same time as you measure the current, or the numbers will be hugely off.


I have those blue ones.

They used to be good, not measured though...

Now, they were on shelf for over half a year. Now they give about 0,4A tops... So, they are busted.

In the beginning they worked just fine for some cycles.

Unfortunately, until a real manufacturer starts making 10440s, there really aren't any other options. All the searching I've done shows the UF, TF, and fake IMR ones seem to be the same cell... yes, even the ones sold as IMR. And no one else makes cells of that size.