TrustFire batteries and more TrustFire: two TrustFire cells in 14500 and 18350 sizes

I recently got some batteries from one of the “well-known” brands called TrustFire, so I decided to put together a short review.
Inspection, tests, conclusions.

I originally ordered three types of batteries from this brand: 14500, 18350, and 16340. The last ones have been stuck in customs for a month now, so I decided to write about the ones that arrived.
These battery formats aren't very popular, which makes them interesting, especially since these sizes are less common among brand-name cells and cost more.

This review will follow the same style as my extensive battery test, but in a more condensed form, since there are only two “test subjects.”

Among the many different batteries with “Fire” at the end of their name, TrustFire batteries are better quality. The positive reviews, both mine and other people's, confirm this. Still, they're budget batteries.

First up are the 14500-format batteries, i.e. AA-sized cells.
No complaints about the packaging at all. The batteries come in packs of 4–6, with each pair also protected by heat-shrink tubing.


I ordered 20 cells; the link to the listing is at the very beginning. The listing is for 10 cells, so that's 2 listings.
The count checks out.


The appearance is quite recognizable: the standard black-and-red color scheme. The batteries have a protection circuit against overcharging and over-discharging.


The positive terminal is a button top; the protection circuit is at the other end.


The size is almost as specified: they're 1 mm longer, but that's normal for protected batteries.
The batteries all weigh roughly the same. Really lousy ones tend to vary more.


The stated capacity is 900 mAh, although more reputable manufacturers specify 750–800 mAh.
A basic charger with a capacity-testing function measured 779–828 mAh, a very wide spread. By the way, you can easily judge battery quality by the capacity variation within a batch: the smaller the difference, the better. Branded batteries may vary by 5–10 mAh; really lousy ones can vary by as much as 50%.


But since I run all my tests using a more specialized battery tester, these “guys” got put through that test as well.
And the results aren't encouraging. The test was run at a charge/discharge current of 800 mA, with discharge down to 2.8 V.
The first one measured 723 mAh.


The second one did even worse: 687 mAh.


Thinking that a discharge test at almost 1C might be too much for them, I tested the first battery at 0.5C, i.e. 450 mA
And got even less: 714 instead of 723 :(


This really surprised me. Not because they’re TrustFire, but because I’d already tested batteries from this brand and the results were much better.
You can read the review and see the test results at the link above. I bought those batteries about two years ago from the ChinaBuye store (yes, they turned out to be cheaper there), and I still had a few at home. I grabbed battery number 18, which showed a capacity of 900 mAh in a basic charger at a discharge current of 1 A.
I started the test and got 772 mAh.


Since I was getting rather absorbed in this process, I decided to test an old battery under the same conditions as two years ago. I even used the same slot in the charger.
833 mAh (it was 900 two years ago), compared with 803 and 769 for the new ones. So there you have it: a two-year-old battery managed to beat its younger “namesakes.”
Unfortunately, I’d already confirmed receipt and left a review. I did write it based on the test with a basic charger, though, so now I’m wondering how to change the review.


Now on to the second type, 18350. I haven’t tried these before.
The batteries are sold in lots of 4, at $11.74 per lot, or about $3 each. Product link.
I ordered 5 lots, i.e. 20 batteries, in two packages

This seller took even greater care with the packaging: two cardboard boxes, each packed with plenty of cushioning material, with the batteries themselves in a bag. Each battery was also individually wrapped in film.
For some reason, each box also had a sticker with a photo of the batteries.


No complaints about the quantity: 12 + 8 batteries.


Each battery also has its own little paper label, which says in perfectly understandable Chinese that these batteries were made in November this year, are size 18350, and have a voltage of 3.7 V and a capacity of 1200 mAh.


These batteries have a slightly revised case insulation design, and they are unprotected. The positive terminal is a button top.


The dimensions are basically fine; they’re a little longer because of the electrical tape I used to cover the positive terminal. The weight difference is slightly greater than with the 14500s above.


Four cells were selected at random for testing. Capacity varies quite a bit, ranging from 912 to 969 mAh across the four “test subjects.”
This charger overestimates capacity during testing, but even so, the result is noticeably below the claimed figure.


Since I use a basic charger only for a rough estimate, I picked a pair of the cells tested above for a more detailed check. These were cells 3 and 4.

Cell 3 delivered 886 mAh at a discharge current of 1 A, with the discharge cutoff set to 2.8 V, as before.


Cell 4 came in lower, at 845 mAh, but its result was also lower in the rough test: 912 versus 969. In any case, the cells' actual capacity is about 20–25% below the claimed figure.


As before, I figured a discharge current of almost 1C was too high, so I tested at 0.5C, i.e. 600 mA.
Cell 4 was tested and delivered just 820 mAh. This once again confirmed that a lower discharge current does not always mean a higher capacity in mAh. In Wh, the capacity was slightly higher in the second test, so that is the figure you should pay more attention to when testing.
People often ask me how it can be that, for example, 970 mAh “went into” a battery during charging, but 1000 mAh “came out.” The answer is simple: to estimate a battery's “efficiency,” don't look at capacity in mAh; look at capacity in Wh instead. That's a more accurate comparison.


By the way, about the design: to my surprise, I happened to find out that these batteries come with two types of wrapper, either with the nice “Rechargeable battery xxxx mAh” lettering or without it. This has no effect on battery quality. The photo shows perfectly decent 26650 and 18650 cells from this brand.


But you also come across outright duds. The cell on the right in the photo is a 16340 from the same brand, but the test results showed it to be complete junk. I have some cells of exactly the same size stuck in customs, and at this point I don't even know if they'll ever arrive.


So, the batteries didn't quite live up to my expectations. I wanted to buy cells from the same brand, but the “blue” ones I bought before turned out to be pretty good quality. Unfortunately, they're either unavailable or inexplicably expensive. Maybe someone can share a link to an inexpensive option for 14500 cells? I'd really appreciate it.

That's about it. This turned into a short little review, but I hope I didn't write it for nothing and that someone might find the information useful. I'll try to “shake” at least a small compensation out of the second seller.