Thanks!

Check powerwall application, it's doing what you described

I can't really tell. I can only say, from what I've tested (and I did way more since this video) they seem to be what they are representing. I probably purchase more then 200cells by now and so far no problems, I had 0 broken cells. I am planning to post a new video in the following months comparing few more cells with some more extensive testing.

Links en la descriciòn del video.

Thanks!

I added the links in the description, not sure if was appropriate to post them as a comment. Thanks for watching!

@@thediyed much appreciated. If you come across good bms's or other cool stuff make a video about it. It's so hard to tell what is good from these Chinese sellers. Cheers

Try Battery Junction

This is one of the oldest way of getting cheap 18650. There is a big chance you will have good ones. But you will need to to few discharge cycles and then leave them for a few days and check if there is a drop of voltage. If they pass the test they are good to go. Just having in mind mixing different brand of cells might be a problematic as almost often they don't have the same specs.

Says on the battery made in Japan

@@fredhinck9685 and u belive thst?

The cutoff when the cells are being used and you use a proper BMS it varies between 2.7v to 3v. Some BMS you can control this and set your limit. But for testing purposes you go to the manufacturer cutoff to test the capacity.

@@thediyed Which, you obviously didn't do, because both cells had voltage measurement way less then 2.0 volts.

I can't really tell if they are a copy or other less known cell that is reskinned as a Panasonic. I can tell you from the weight, capacity, etc. It is everything that is should be to be a Panasonic. I probably purchased over 200cells and they are still going strong, and I am not gentile with my ebike when riding it, so the cells are holding up.

@@thediyed From what I was able to see from your meter it tipped 3000 at 2.5V? If that's right it's far away from spec? And did you get 25mOhm DC? That's also low. Which is good, in the wrong way. The insulation ring also looks suspicious, but hard to tell on the video. If they work consistently that's what's most important 👍

Its easy to fake tho, and I saw 50-51g already

just weight as a test is not enough. I am stress testing the cells, this is the best way to get to the real results. I might do a second video of my improved testing.

Exactly 👍

The difference of 152 mWh is likely much less than the measurement error accumulated during the testing. His rounding it down to 10,000 mWh wasn't a major deal.

@@exgenica You don't get the point. It is not 10 thousand, it is 10 and a little. 10 point 152. See?

​@@Sekir80 Thanks for making the point, but the cause is not what you think. The problems were: 1) The comment to which I was responding used the wrong scale and I perpetuated it in my response. It didn't help that "Stefan" seems to have conflated European and U.S. methods of delineating with a decimal point vs. a comma when he "corrected" the video author by seeming to use BOTH...claiming it was actually, "10,152 wh Not 10.000" That was further compounded by... 2) *I didn't fact-check what the video author kept saying and lazily used the same wording* that "The DIY Ed" kept saying throughout the video ("thousands" of watt hours). But, thank you for pointing out the error. Examples of him saying "ten thousand watt hours", "eleven thousand watt hours", and so on are at timestamps 6:20 6:40 10:30 10:50 11:25 .... So there were two people saying "X thousand watt hours" and I just rolled with it. I didn't make the connection in my mind that his watt hour scaling was wrong and so just kept using what he was using. I've corrected my comment to reflect your observation, even though it now conflicts with what the video author was saying.

@@exgenica Oh, yes, your comment makes absolute sense! Thanks for getting back to me. This video is horrendous on many scales. The 10 thousand problem is clear now. I like the device he used to capacity test the batteries, however what he did is a huge error! If you want to go easy on a cell (and keep cycles on the high side, meaning having a long life) you never discharge it below 3.0V. Heck, even 3.2V. If you wanna squeeze most of the juice you can go below 2.8-2.7V, but certainly not recommended. Most standard tests (found in battery cell datasheets) aim for about this level. But you certainly do NOT discharge a cell below 2.0, 1.8V! That will degrade it extensively! He did that, achieving enormous capacity results. Very much not recommended hence the result is pretty much useless. Fortunately, the timelapse shows all the data and we can assess how good the cell really is. I commend for this video for this reason.

The Opus (and Lii 500) is not usable if you are testing against mfg's specs, fine if all you are doing is testing some cells for a powerwall, ebike battery or similar. On the other hand this setup is no good either.