Vapcell F52 21700 5200mAh Batteries

It's been quite a while since I last wrote about Vapcell batteries, but things worked out so that they sent me a package with four samples. So today, here's part one: 21700 batteries rated at 5200 mAh.

As usual, a reminder: to keep up with new posts on the blog, I recommend following me on Instagram, where I'll post notifications about every new article and maybe write about something interesting too — link to my account

So, they sent me a box of assorted batteries, and I certainly don't mind—especially since batteries are in high demand these days. Besides, I already have some ideas for how to use them, and have even put a few into practice. I'll tell you about that soon, too.

They come neatly packed in the familiar Vapcell branded boxes, but as I've said more than once, I wish they offered them as an optional extra.


The color is a light lime green, with the usual markings, key specs, and scratch-off code. The positive terminal is flat, and all the batteries look identical.


No issues with the dimensions either. There was some variation in weight, though I wouldn't call it significant.


Specifications
Model: F52
Size: 21.1±0.2 * 70.8±0.3mm
Typical Capacity: 5200mAh (0.2C discharge)
Min capacity: 5050mAh (0.2C discharge)
Nominal voltage: 3.60V
Max Continuous Discharge Current: 15A
End-of-charge voltage: 4.20V
End-of-discharge Voltage: 2.5V
Weight: 72g ( Appr)
Internal resistance: 15mΩ ( Appr) （AC 1kHz）
Standard Charge: 2000mA,CCCV 100mA cut-off
Quick Charge Current: 4000mA

The first run was done with a Vapcell S4 charger. The batteries were initially charged to about 40%, and both samples were at the same level. A “conditioning” cycle showed a capacity of around 5100 mAh.


As you can see from the specifications above, the batteries have two stated charging modes: standard at 2 A and fast at 4 A.
At 2 A, a full charge took 2 hours and 50 minutes, which is perfectly normal for batteries like these.


At 4 A, the battery charged in 1 hour and 45 minutes. That's relatively slow in my view, so I wouldn't recommend using this mode; I'd stick to 2–2.5 A.


Vapcell's website has test graphs at 2, 10, and 15 A, with a result of 5148 mAh or 18.5 Wh at 2 A. A reminder: the correct way to measure capacity is at a current of 0.2C.


I measured the batteries in five modes: 0.2C, 0.5C, 1C, 10 A, and 15 A, where C = 5.2 A.
The first sample delivered 5044 mAh or 18.23 Wh, which is reasonably good and also more than 5000 mAh, but still less than the rated capacity.
The batteries also performed well at a 15 A discharge current, but in my view that's the maximum discharge current. For a longer service life, I'd limit it to 10 A.


For batteries with relatively high discharge currents, I sometimes run a residual-capacity test, which gives a good indication of how efficiently they deliver power under maximum load. The test is performed at 0.2C after discharging at the maximum current and letting the battery cool to room temperature. The lower the result, the better. The first battery delivered just 58 mAh here, which is an excellent result.


Temperatures during discharge at 1C, 10 A, and 15 A were also quite good, peaking at around 70 degrees. However, these batteries are more on the high-capacity side, so temperature is more critical for them. The test therefore confirms what I said earlier about 10 A being the maximum safe continuous current.


The second sample delivered 5045 mAh or 18.24 Wh, 1 mAh more than the first. On the one hand, I didn't get even the claimed 5150 mAh; on the other, the results are highly consistent, and it's hard to say which is better or worse in this case.


The residual capacity is a little higher here, but still very good.


The temperatures are about the same, though it would be surprising if there were any noticeable difference.


Repeatability tests at 0.2C, 1C, 10 A, and 15 A showed that the results aren't just good—they're excellent. This indicates that genuine Vapcell cells are clearly being used. I'll say more: I recently tested almost 500 LG batteries, and the variation was even greater. If you're interested, I'll publish the results.


As I mentioned, this time Vapcell sent me four of each at my request, and it wouldn't have been fair to just leave them sitting in a box, so I tested the second pair too, but with a shorter test program: only at 0.2C, 1C, and 15 A.

These batteries also had identical characteristics. They did deliver a little more, but I suspect that's because they were tested later, when the air temperature was a couple of degrees higher.
But there's one "but" I noticed while putting together the summary graphs: the fourth test subject showed an odd voltage drop toward the end of the discharge. When I loaded the graphs at 0.2C, I initially thought the test itself had gone wrong somehow. But after loading the graphs at 1C and 15 A, I changed my mind: this seems to be a peculiarity of this particular battery.
I always say that a battery's discharge graph is like the photo in its passport: it's almost unique to each model. That's why I was surprised that at 0.2C (the standard measurement rate), the graph was 100% identical across all other sections, except for that strange dip near the end. This is the first time I've seen anything like it.


And here's the combined graph for all four cells at 0.2C and 1C. I spotted a second oddity here: it turns out the fourth cell didn't have a voltage drop; rather, the third one (green) had a strange rise. More precisely, the first and second had identical graphs, while the third and fourth differed in opposite directions, making the differences more noticeable in the combined graph.
All in all, a bunch of oddities.


The heat-shrink tubing shifted a little during testing. This is a characteristic feature I've mentioned and written about several times: the original heat-shrink on branded cells doesn't creep even at temperatures above 100 degrees, whereas this one had already slipped a little at 70. I wouldn't call it a problem; just something to keep in mind.
The first pair is on the left, the second on the right.


Impedance measurements after receipt, after the conditioning cycle, and after testing. The relatively wide spread isn't accidental: I deliberately picked the samples with the widest spread for the test. But as the results showed, that didn't stop them from delivering almost identical results.


And here are the results for the third and fourth cells, after receipt and after all the tests.


As usual, a few comparisons. First, one from the Vapcell website, with a discharge current of 15 A.


I decided to compare them not only with a much larger number of other battery models, but also under different conditions: at 0.2C, 1C, and 15 A.
The comparison included:
The Vapcell F52 under review
LG INR21700-M50T
Samsung INR21700-50E
Samsung INR21700-50G
Vapcell T50
Vapcell G50
Vapcell P50

At 0.2C, the discharge graphs for all the batteries are very similar, but the ones under review and Vapcell T50 clearly stand out in terms of capacity, although the difference from the others isn't very large.


At 1C, the difference became much more noticeable, reflecting the batteries' different current-delivery capabilities. The highest results were still from the cells under review and the Vapcell T50.


At 15 A, the cells that struggle to deliver that much current clearly stood out. Even so, the cells under review and, once again, the Vapcell T50 came out on top in mAh delivered. But there's "one catch": although the Vapcell T50 delivered fewer mAh, it delivered more Wh: 16.80 versus 16.61 Wh for the cells under review. So it's not quite that simple.


While writing this review and browsing the Vapcell website, I found even more interesting batteries: Vapcell F58, in the 21700 size, with a claimed capacity of 5800 mAh! And I'll say this: I already want to test them, perhaps alongside the slightly lower-capacity Vapcell F54

Come on, how gorgeous are these? :)


And as a preview of what's coming next, here are a couple of photos.


Now for the conclusions.
In my opinion, these are excellent batteries in terms of performance. There's something odd about the graphs, which is a little strange, although it takes a lot to surprise me. Still, the comparison graphs clearly show that these batteries perform well both in terms of capacity and current delivery, matching the other batteries tested and actually outperforming them in almost every mode. Their only worthy competitor is Vapcell T50.

All in all, if you come across them and the price suits you, I can recommend them.

That's all for today. May your home always have light.