Vapcell batteries, sizes 16340, 18650 and 21700

In the spring, I published two reviews of Vapcell batteries, both conventional lithium-ion and LiFePO4. Now I’ve got another batch of cells with this company’s logo. To avoid overwhelming readers with too many reviews, I split the batteries into several groups. Today I’m reviewing the first group.


Last time, I wrote that I liked most of the Vapcell cells, primarily because they generally lived up to their specifications. There were, of course, a few “quirks,” but at least they usually carry their own branding and don’t try to pass themselves off as Samsung, Murata, and so on.

Today I’ll share the test results for three battery sizes: 16340, 18650 and 21700. All tests were performed using two battery testers, EBC-A10H and EBC-A20, rated for currents up to 10 and 20 A, respectively.

The batteries came directly from Vapcell, but since buying through their website is inconvenient, I’ll also include links to their official AliExpress store.



I’ll start with the less common 16340 size. It’s noticeably harder to find batteries like these from well-known brands. They tend to focus on the more popular 18650, 20700 and 21700 sizes, while anything less common—16340, 10450, 18350 or 17650—is unfortunately harder to come by.

Vapcell T8 INR16340 850mah 3A
Product page on the manufacturer’s website — link
AliExpress listing — link, price: $4.93 for 1, $7.89 for 2.



Specifications
Model: INR16340 850mah 3A (RCR123A)
Size: 16.4*34.0mm
Type: button top
Nominal voltage: 3.60V
End-of-charge voltage: 4.20V
End-of-discharge Voltage: 2.5V
Typical Capacity: 850mAh (0.2C discharge)
Min capacity: 820mAh (0.2C discharge)
Weight: Max:20g
Internal resistance: Max:65mΩ （AC 1kHz）
Standard Charge: 500mA,CCCV 50mA cut-off
Quick Charge Current:1000mA
Max Continuous Discharge Current: 3A

The specifications for these and other batteries say they can be fitted with a protection circuit and a raised positive terminal, although in this case the latter is already present.

They come in a branded plastic case, with each battery in its own bag.


The batteries have a scratch-off authenticity code, along with brief specifications and the alternative size designation RCR123A. Keep in mind, though, that their voltage is higher than that of CR123A/RCR123A batteries, which usually provide 1.5–3 V.


The dimensions and weight match the specifications. Interestingly, their 34 mm length includes the raised positive terminal; on conventional 18650 batteries, this design usually adds a few millimeters to the length.


A “conditioning” charge/discharge/charge cycle at a 0.5 A charging current and 0.25 A discharge current showed a capacity of over 910 mAh on the charger’s discharge measurement. However, chargers like this one (as well as Opus, LiitoKala, etc.) often overestimate capacity.


Next, as usual, I measured the charging profile. The specified standard charging current for these batteries is 0.5 A, with a fast-charge current of 1 A.
At the standard current, charging took about 2 hours. In my opinion, the CV phase lasted a little too long.


At 1 A, charging took 1 hour 15 minutes, which is pretty good, but the CV phase lasted even longer.


Before moving on to the main tests, here are the results from the manufacturer’s website. The test was run at currents of 0.5, 2.0 and 3.0 A, and the results are quite good. To be fair, though, testing at such low currents with an EBC-A40L load isn’t entirely accurate, since the measurement error increases significantly. That's exactly why I test batteries like these with the EBC-A10H for greater accuracy.


The batteries were tested at currents of 0.2, 0.5, 1, and 2C, as well as 2.35 and 3 A. The 2.35 A setting was chosen as a midpoint between 2C (1.7 A) and the maximum of 3 A.
Overall, the results are similar, but discharging these cells at currents above 2C is close to pushing them to their limit: the capacity they deliver drops sharply.


The temperature stayed within the acceptable range and didn't even exceed the 60-degree threshold. The temperatures at 2.35 and 3 A are shown below.


The second cell performed even worse: at the maximum current, its voltage sagged significantly and its delivered capacity dropped.


Since the lower delivered capacity meant the discharge took less time, the final temperature was also lower than for the first cell.


I was a little surprised by the test results at 2.35 and 3 A, especially since the manufacturer's figures are noticeably better. So I ended up repeating these tests several times using three different electronic loads, but the differences were within the measurement error. At one point I thought I'd simply "killed" the cells, but a repeat test of the first cell at 0.2C and the second at 1C showed that, essentially, nothing had changed.
Bottom line: the maximum continuous current for these batteries is 2C, or 1.7–2 A.


Battery impedance right after arrival, after "conditioning," and at the end.



Vapcell INR18650 3000mah 20A
A common size, capacity, and maximum current. I think many of you know popular models like these, for example the VTC6, HG2, and 30Q.

Model on the manufacturer's website — link
Model on AliExpress — link, price: $10.86 for 1 pc., $14.81 for 2 pcs.



Specifications
Model: INR18650 3000mah 20A
Size: 18.3* 64.9mm
Nominal voltage: 3.60V
End-of-charge voltage: 4.20V
End-of-discharge Voltage: 2.5V
Typical Capacity: 3000mAh (0.2C discharge)
Min capacity: 2900mAh (0.2C discharge)
Weight: Max:48g
Internal resistance: Max:12mΩ （AC 1kHz）
Standard Charge: 1500mA,CCCV 100mA cut-off
Quick Charge Current:4000mA
Max Continuous Discharge Current: 20000mA

This time, the batteries arrived in nicer, more convenient packaging: a small case with a clasp. I don't know whether it comes with the order from AliExpress; you'll have to check with the seller. But it's useful in principle.


The manufacturer's website and contact email are printed on the bottom.


As with the previous ones, there's a security code and brief technical specifications.
The positive terminal has a three-pronged design and looks more like the one on the Samsung INR18650-30Q.

The photo makes it look blue, but in reality it's closer to purple.


But the marking on the safety vent looks more like the one used on the VTC6, so I'm leaning toward that being the model.


The dimensions and weight are all within spec.


A conditioning run at a discharge current of 0.5 A showed a capacity of about 3200 mAh.


According to the specs, the battery's standard charge current is 0.5C and the maximum is 4 A. At 0.5C, charging takes 2 hours and 16 minutes.


At a charge current of 4 A, charging takes 1 hour and 12 minutes. Not bad, but the CV phase takes a long time. In general, I wouldn't recommend going above 3 A: you won't save much time, and the battery will last longer.


The tests were run at 0.2C, 0.5C, 1C and 2C, as well as at 10, 15 and 20 A. Discharge was cut off when the voltage dropped to 2.5 V, as specified.
The results were excellent in every mode. The battery easily handles currents up to 20 A, and at currents up to 10 A it still delivers 3000 mAh.


Heat was no concern either. Even under the heaviest load, the temperature was only a little over 90 degrees. Below are the measurements at 10, 15 and 20 A.


The second sample performed just 10–20 mAh worse than the first, which is well within the test's margin of error.


The temperature was slightly higher, but nothing critical.


The comparison graph shows that the cells under review are very similar to the VTC6, though they perform slightly better.


Battery impedance right after delivery, after conditioning, and at the end.



Vapcell G50 21700 5000mah 15A
The 21700 form factor is replacing the 18650, with a larger size and higher capacity. I already had a couple of models in this size with the same capacity, but here I'm more interested in how it performs at the maximum rated currents.

Model on the manufacturer's website — link
Model on AliExpress — link, price: $8.53 for 1 pc, $12.80 for 2 pcs.



Specifications
Model: G50 INR21700 5000mah 15A
Size: 21.1*70.5mm
Nominal voltage: 3.60V
End-of-charge voltage: 4.20V
End-of-discharge Voltage: 2.5V
Typical Capacity: 5000mAh (0.2C discharge)
Min capacity: 4900mAh (0.2C discharge)
Weight: Max:72g
Internal resistance: Max:15mΩ （AC 1kHz）
Standard Charge: 1000mA,CCCV 100mA cut-off
Quick Charge Current: 2500mA
Max Continuous Discharge Current: 15A

Like the previous ones, these came in a branded case with a clasp.


I can't say for sure who actually makes these cells, but the shape of the rim around the positive terminal looks familiar. I've definitely seen similar batteries before, though with different specs.


Dimensions and weight


In the conditioning run at a discharge current of 0.5 A, they showed a capacity of about 5170 mAh. As with the previous ones, they arrived with an initial charge of around 30–40%.


Two charging modes are supported: standard charging at 1 A (0.2C) and fast charging at 2.5 A (0.5C). Generally, the normal charging mode is just way too slow. I also can't remember any battery models with a recommended charging current below 0.3C, even among the highest-capacity ones, so I'd probably charge these at 1.5–2 A.
At 0.2C, charging takes a little over 5 hours.


At 0.5C, charging takes almost 2.5 hours.


This battery model has already been tested on a well-known site, and this graph is from the VapCell website.
They tested the batteries at currents up to 30 A, but I thought that was unnecessary and decided to stick to the modes specified in the datasheet.


The tests were run at 0.2, 0.5, 1, 2, and 3C, where C = 5 A.
Yes, the capacity is slightly below the claimed 5 Ah, but I wouldn't say a 30 mAh difference is all that significant. Besides, the battery performed well even at the maximum specified current.


The temperatures at 10 and 15 A look perfectly reasonable to me.


The results for the second sample are almost a carbon copy of the first.


The temperature results are much the same, too.


But the comparison with the closest competitors turned out to be much more interesting: Samsung INR21700-50E and LG INR21700-M50T.
All three models have similar rated capacities and almost identical maximum discharge currents (14.55 and 14.7 A).

Below are the results at 0.2, 1, and 3C. At 0.2C, they're practically identical, even the discharge curves have the same shape. But at 15 A, the VapCell performs noticeably better: Samsung and LG delivered around 15 Wh, while the VapCell delivered 16.2 Wh.



Battery impedance right after delivery, after “conditioning,” and at the end. Here, too, the difference is almost twofold compared with Samsung and LG, at 22.


And now, as always, the conclusions. This time they'll be fairly brief.
T8 INR16340 850mah 3A - Decent batteries overall, but they should only be discharged at up to 1.7–2 A. They fall well short of the claimed 3 A discharge current, which is a shame.
Vapcell INR18650 3000mah - Very good batteries, with specs similar to Murata's VTC6. I'd probably even say these are VTC6 cells, so everything that applies to the VTC6 applies to the ones reviewed here as well.
Vapcell G50 21700 5000mah - These batteries really managed to surprise me. Not only do they have higher capacity than their Samsung and LG competitors, they also perform noticeably better at the maximum current. Their impedance is half as high, too, which is reflected in the temperature: 78 degrees versus 83–90 for the “big-name brands.”

In short, the 16340 failed the test at currents above 2 A; I have no complaints about the others.

That's all for today. I hope you found this useful.