VapCell IFR26650 2600mAh 3.2V 55A/75A batteries

Batteries with the highest maximum discharge current featured in my reviews so far: 55A. Unfortunately, I could only test them at 40A because of the limitations of my equipment.

I’ve already reviewed several LiFePO4 batteries, but as an introduction, let me recap how they differ from conventional ones.
At first glance, these batteries seem less attractive than the familiar Li-Ion cells: they have a lower voltage and, accordingly, a lower capacity, which means a higher price per Wh. But they have several undeniable advantages: often a higher maximum charge and discharge current, greater safety, and a very flat discharge curve. They can also be used in buffer mode, provided their voltage is kept at 3.35–3.40 V.
Another argument in their favor is that they can operate at lower temperatures, although this doesn’t apply to every model. There are also conventional lithium batteries rated for operation down to -40, such as cells from Molicel.


The model on the manufacturer’s website — link
This model is available on AliExpress in several listings, with different prices and shipping options. Here’s a link to one of them; the price is $16.49 for 2 pcs.


Main specifications
Model: Vapcell IFR26650 2600mah 55A/75A
Size: 26.6*65.1mm
Nominal voltage: 3.20V
End-of-charge voltage: 3.60V
End-of-discharge Voltage: 2.0V
Typical Capacity: 2600mAh (0.2C discharge)
Min capacity: 2500mAh (0.2C discharge)
Weight: Max:90g
Internal resistance: Max:5mΩ （AC 1kHz）
Standard Charge: 2500mA,CCCV 100mA cut-off
Charging Time: 1.5hours(standard charge)
Quick Charge Current: 12000mA
Max Continuous Discharge Current: 55A
Max Discharge Current: 75A under 80°C

The package included a battery storage case. As far as I can tell, it’s also included when ordering from the link above. I like the case—it’s sturdy, though for some reason it has a little pocket on top again.



The positive terminal is flat, almost flush with the front end—perhaps even slightly recessed. As with some other batteries, you can also order a version with a cap over the positive terminal that adds 2 mm.
As on the other models, the basic specifications are printed here too: capacity, voltage, and continuous/maximum discharge currents.


The dimensions are roughly as specified, and the weight is within the expected range. Interestingly, these batteries weigh 85–86 g, while the 5300mAh 26650 Li-Ion cells from my previous review weighed 95 g. I can’t say whether this is due to the different chemistry; it’s just an observation.


Since my basic charger can’t handle batteries like these, the preliminary cycle was run on the same equipment as the other tests. The graph shows the results of the first and second cycles at 0.2C. The difference between the capacities of the test samples, as well as between the first and second cycles, is only a few milliamps.
The batteries were initially charged to about 40%.


The recommended charging current for these batteries is 2.5 A, with charging terminated when the current drops to 0.1 A. Both batteries were charged in this mode for all the tests.
With these settings, charging a battery takes about 1 hour and 11 minutes, which is an excellent result.


The product description also claimed that the batteries could be fast-charged at 12 A. I tested this too: charging took 20 minutes in this mode.


The product page includes a test graph based on measurements by the manufacturer, which I can compare my results with.


In my tests, I used currents of 0.2, 0.5, 1, and 2C, as well as 10, 15, 20, 30, and 40 A. That meant I ran out of my usual seven colors.
The battery easily delivered the rated 2600 mAh at 0.2C and 0.5C. Even more impressive, it delivered over 2500 mAh at currents of 20–40 A.


Temperature at 20, 30, and 40 A.
Unfortunately, even 40 A turned out to be too low a current to really test these batteries: even at 40 A, the temperature only reached 65 degrees. The manufacturer recommends keeping them below 80 degrees, and judging by the temperature trend, I’d say they would reach that temperature at around 50–55 A.


The second battery produced similar results.



Besides running into the limits of my measurement equipment, I also had a problem with the battery holder. It was originally designed for currents up to 20 A, so it gets noticeably hot at 40 A. Buying a new holder for almost 30 dollars seems a bit steep, so I’ll probably have to look for a higher-current contact assembly.


1. The test process through the thermal camera’s “eyes.”
2, 3. The wires to the holder reached about 85–87 degrees. Looks like I need to replace those too.


Out of curiosity, I compared the test graphs for the two batteries at 0.2C, 10, 20, and 40 A. They’re identical at 0.2C, but at higher currents the first battery falls noticeably behind. I may run another test just for fun, testing the second battery first and then the first one.


I was also pleased with the low internal resistance, which came in at around 4.5 mΩ. My tests didn’t affect it at all, even at 40 A.
Results before testing, after the preliminary cycle, and after all the tests.


I could wrap things up here, but I found an interesting comparison graph on the manufacturer’s website. It compares these batteries with cells of the same size and capacity from the well-known manufacturer A123, and the graph suggests they outperform the cells under review.
I plan to check this, since some batteries of that type are already on their way to me :)


To sum up, I have just one complaint: the price. There’s really nothing else to fault. The batteries delivered a sustained discharge current of 40 A without breaking a sweat, and judging by the temperature trend, they can handle even more. A little more capacity would be nice, of course, but with this size and these discharge characteristics, that’s probably not realistic.