Review and test of batteries from nkon.nl, Sony/Murata VTC6

The latest review in the “batteries from nkon” series. Today we’re looking at the Murata VTC6, which in my opinion are just as popular as the VTC5A. There’s also a bit of useful information at the end of the review; some of you may already know it, while others may not.


In my personal opinion, the VTC6 batteries are more in the medium-current category, since their maximum current is 20 A. But as I’ve already written, the boundaries and definitions are pretty blurry, so they could just as well be classed as high-current batteries.

A short excerpt from the datasheet, showing the main specifications.


They look almost identical to the VTC5A shown earlier: the same color, almost the same markings, and the same flat positive terminal.
According to the code 0968382AH27J, the manufacture date is August 27, 2018.
The dot-matrix markings on the batteries are different, so there’s a good chance they’re genuine :)


The dimensions match the datasheet. The weight is slightly higher, 46.8 grams versus 46.5, but I don’t think that’s significant, since the datasheet gives an average weight.


The manufacturer specifies an internal resistance of 12.8 mΩ; I measured 12.6, which is also within the normal range.


A “conditioning” cycle and the first capacity measurement: I got about 3200 mAh at a discharge current of 500 mA.


After that, I connected it to the main electronic load.


As last time, there are some quirks with charging. But since I found that the difference wasn’t very large, I ran the tests with a charging current of 3 A (1C), a cutoff voltage of 4.2 V, and a cutoff current of 100 mA.


Test results, discharge cutoff voltage: 2.5 V
Red — 0.2C — 600 mA
Orange — 0.5C — 1.5 A
Yellow — 1C — 3 A
Green — 2C — 6 A
Light blue — 10 A
Blue — 15 A
Purple — 20 A


Battery temperature at the end of discharge at 10, 15, and 20 A.


And once again, I’m back to the oddities in the datasheet. Last time, the capacity was specified at a discharge cutoff voltage of 2.0 V, while all the test results were shown for 2.5 V. This time it’s almost the other way around: the datasheet specifies discharge to 2.0 V at 0.2C and to 2.5 V at 10 A, while the graph shows discharge to 2.0 V at every load current except 20 A.
As they say, everyone’s off doing their own thing.


In the end, I decided to test the second battery with discharge down to 2.0 V at every load current.


The temperature went up slightly, by just a couple of degrees. The discharge from 2.5 to 2.0 V takes very little time. Even so, it stayed below the 90-degree limit for these batteries (at that temperature, discharge must be stopped).


Here are the comparative results for the first battery discharged to 2.5 V and the second to 2.0 V, at 0.2C (600 mA), 10 A, and 20 A.


That could have been the end of the review, but I’d like to add a little more.
First, I dug an original Sony VTC4 battery out of my “stash.”


1, 2. Comparison of three batteries: VTC4, VTC5A, and VTC6.
3, 4. These are fake VTC5 cells. The code is hard to read; some of it came off with the electrical tape they were wrapped together with, but if you look closely, you can see that the codes are identical.
By the way, I noticed that the heat-shrink tubing had split under the blue electrical tape they were wrapped with. It had simply dried out.


But what really caught my interest was something else.
I’d never really thought about how Sony/Murata batteries are labeled, but if you look more closely—and especially compare the labels with the discharge current—it becomes clear why they’re marked this way.
VTC4 - 2000 mAh - current at 0.2C = 400 mA
VTC5 - 2500 mAh - current at 0.2C = 500 mA
VTC6 - 3000 mAh - current at 0.2C = 600 mA

Intrigued by this labeling pattern, I wondered if there were other models too. I searched for VTC3 and found a datasheet for Sony VTC3 batteries rated at 1500 mAh (current at 0.2C: 300 mA).


As far as I understand, though, these batteries have been discontinued and replaced by the VTC5. At least, the maximum discharge current of 30 A suggests that’s the case.


Then I got even more curious. If there are VTC3, 4, 5, and 6, could there also be a 7?
It turns out there is, although it’s called VC7, not VTC7.


Its capacity also fits the labeling: 7 = 700 mAh × 5 (0.2C) = 3500 mAh.


Judging by their capacity and discharge characteristics, these batteries are almost identical to the Samsung INR18650-35E and Panasonic NCR18650B models I reviewed earlier. Given their maximum discharge current of 8 A, they’re probably more similar to the INR18650-35E.

I wonder if there will be VC8 cells. Though that’s probably unlikely. I think this will be the end of the 18650 form factor, as 21700 batteries are gradually becoming more common.


To sum up, I can say unequivocally that these are genuine batteries and meet their stated specifications. I definitely recommend them.

That’s all for now. Thanks again to Vladimir for providing the batteries for testing. I hope this information is useful.