I got and tested the Varicore batteries some time ago.
I started on in once, but it died on me. The problem is when they use a single mosfet transistor, standard mosfets are not good at analog regulation and cannot handle anything like the rated power when doing that.
That cell is a problem, it will not fit in my battery holders, 70mm long is about maximum I can test.
I guess it died once you tested it at some power level within theoretical specifications, do you remember how much was that?
Found a review of it: Queen Battery QB26800 6800mAh 20A - the big guy! @ Thunderheart Reviews
Nice battery holder, doesn't it? :-D
It was close to maximum rated power.
It is similar to the ones I used before.
I bought some aaa batteries from ebay. The picture showed contour batteries. I think this is a good company which closed down or something…when they arrived they were Digimax. I discharged then charged them at 200mA in an Accupower IQ328 and two of them kept fluctuating between 1.41v and 1.42v. I ended up stopping the charge after 5 and a half hours! I know the current should be at least 0.3C but I wasn’t expecting this from brand new batteries. I always select the lowest current for new cells and when condition cells.
Today i tested the “7000mAh” LiFePo4 cells after they are used for more than 10 months in the solar powered light. https://nl.aliexpress.com/item/32878468860.html?spm=a2g0z.10010108.1000013.5.3d9e7580Cyry4Y&pvid=c5572a18-c89d-440b-a640-9a2bed6460af&gps-id=pcDetailBottomMoreThisSeller&scm=1007.13339.90158.0&scm-url=1007.13339.90158.0&scm_id=1007.13339.90158.0
According to the HTRC B6V6 balance charger the discharge capacity of the 2S battery pack is still 6459mAh (about the same as in the first test, almost one year ago).
The balance board does not balance the cells, but that is no problem because charging and balancing the battery pack after taking it off the wall took only 4 minutes and 2 seconds
(The cells were charged and balanced before capacity test.)
If there would have been a large difference between the two cells, the charge/balancing time would have taken much longer than 4 minutes.
These cells are much better than the Original lead-acid battery that became useless after about one year.
A new 6V/4A lead acid battery is also more expensive than these cells + the protection board.
The LiFePo4 cells are still like new, it looks like they will last many years in that solar powered light.
I like the tests of new cells, but i am also interested in re-tests after they have been used in “real life conditions”.
I know it is very difficult to do that, but in this case i will continue testing these cells once a year
In my experience balance boards are designed to start resistor draining the cells at some overvoltage (overcharge) point. This, in my opinion, is a simple but effectively useless approach as overvoltage hastens cell damage (you want your cells to live long, not to die soon).
To keep cells in balance manually I would install voltmeters and pushbutton enabled bleeding resistors at each battery stage.
Hello HKJ,
Have you planned to test the upgraded version of the formerly reviewed Kentli or the AAA version?
Not really, but now you asked I decided to order them.
I saw some NCR18650ga on aliexpress I’m curious about for ~$2/ea. Do you have any opinions about them?
https://www.aliexpress.com/item/33026381615.html
https://www.aliexpress.com/item/4000291832886.html
https://www.aliexpress.com/item/4000291932072.html
https://www.aliexpress.com/item/4000278525687.html
Not really, neither the wrapper or button top is original, but I do not know if the battery is original (Probably not).
Thanks, I’ll save my money
I've seen such top before (BAK 18650-34T), take a look right here. Not a bad cell, but I prefer not feeding bad business models. You can buy BAK 34T cells with a lot less misleading wrapper. For example:
https://www.aliexpress.com/item/32960738521.html
I think this cell is in Henrik's testing queue or it has already been tested under some spurious wrap. 
Hello HKJ, I suggest you the test of a new cell in format 18500 that I discovered recently and which offers better capacities than those proposed by Sanyo, Panasonic or even more recently the rewrapper “Vapcell”. It is a cell manufactured by YLE (YikLikEnergy) in the format 18500 with a nominal capacity of 2250mAh (and it is not exaggerated!) For a continuous maximum discharge announced at 4 Amps, to see if in reality we can not push to 5A see more … They are sold in pairs what will arrange you I think for a test, here is the link to buy a pair (box provided):
Oh yes, I was going to forget the delivery is free for Denmark 
Certainly interesting, HydrAxx. However, being one who among other things is always looking for optimizations, I had to look for alternative sources:
Besides a typical overstated capacity rating in the wrap, funny second picture, the guy who made it knew very little about batteries. 
Of course I won't say it is 100% sure both batteries come from the safe factory, but very very likely. ;-)
Personally, i have tested the YLE 18500 2250mAh, their announced capacities are reals but according to the returns I had on “YCDC 18500 2500mAh” they would be 18500 2000mAh with the exaggerated capacity, incidentally there is no official datasheet for “YCDC” while the ” YLE 18500 2250mAh “have an official datasheet as you can see in my post. And yet I’m not a big fan of Chinese manufacturing cells, but this one from YLE are really excellent I must admit, even Panasonic does not do as well.
Mmmkay but, who is YCDC? These plain orange wraps are far from what any serious OEM would use, and what I was trying to imply is that the “YCDC” cells are probably being manufactured by the same OEM, Changde YikLik Energy, but later rewrapped by a 3rd party who buys cells in bulk from them; maybe lesser grade cells. The cell top is the same, 5 lobes/legs and same shape I'd say.
It is great to have advancements in other cell formats, but given the above price… :facepalm:
Nightwatch uses 26980 cells with supposedly very high current carrying capability.
Would be nice to see how do they fare against 30T…
I have such an electronic load. She is a very good assistant for various purposes. Unfortunately, its power is limited to the level of 150W, but it is advisable not to exceed the power of 140W, so if you check prefabricated batteries with a high voltage (for example, 14S = 58.8v), then the current must be selected no more than 2 amperes. I checked the battery for the electric bike and made a mistake by setting the current to 3A, after which it failed and I had to repair it (the output transistor, Schottky diode burned out and also on the circuit board there was a break in the current path).
The cell is too long for my standard test rig.
Your tests are more like not only a test, but the destruction of elements under currents of various levels. Why do elements on your tests need holders if the vast majority of elements after such checks are then not suitable for sale or normal use? Your tasks are of a completely different nature and purpose. You create invaluable experiments that open up opportunities for all of us to evaluate the behavior of various participants in your tests with their strength tests. Your visual graphic pictures help us a lot to understand and evaluate the behavior of batteries at a wide variety of loads, after which it becomes clear how they can be loaded and how best to not do it. Those batteries that you test, after your tests, can be thrown into the trash, because under your professional guidance they have already completed their main combat mission. With your help, we get evidence about all the possibilities of a particular battery model in order to select the most appropriate elements for certain consumers as competently as possible.
From all of the above, it is easy to guess why for batteries 26800-26950 you absolutely do not need large holders. Using a conventional soldering iron, you can simply solder the AWG wires to their contacts, which can then be connected to your loads for control measurements. It is only necessary to solder without any expensive (home-made or branded) and very rare type of holders. Why are these holders needed, if it is necessary to carry out testing up to the complete destruction of the elements, which can then be simply thrown away, before that only by removing the control AWG wires from them? In addition, holders can negatively add transient resistances that increase at high currents, especially after a load current level of 5-10 amperes, which is not desirable for any of us.
In short, we all look forward to checking out the new 26800 format
