How to Test 18650 Batteries Capacity if its Real or Fake

[@SundayOwens]

Thank you for the review

[@sf4Guy]

Really good info. Thank you for the video

[@cesarquintero_]

Podrías darme el link del proveedor o vendedor de Aliexpress que te vendió las baterías 18650 originales?

[@charleslyell3748]

Links en la descriciòn del video.

[@andredejager3637]

Thank you, appreciate the links too :)

[@thediyed]

Thanks!

[@kernowconnection]

I have a battery tester that goes up to 20A 200w 30v

[@ZsoltBoda]

Thanks for the test. Any idea if it (panasonic one) is a liitokala or varicore in reality?

[@thediyed]

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.

[@AlcoveShadow]

Where can I buy that discharge heatsink fan device?

[@juniorsuleiman8924]

If i have high drain 18650 and written on it 30 a how to know if it is real 30 a?

[@gamingtech-tamil]

can i charge and discharge at the same time this battery, i like to use as continues power supply for my camera

[@mad4evr]

Check powerwall application, it's doing what you described

[@shaputer]

The BEST and quickest way to do this ...............is to weigh the batteries. The my 18650 30mah batteries I have are ~45g. They are genuine eFest. The fake ones are noticeably lighter in weight.

[@joeblack5253]

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

[@thediyed]

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.

[@falconfawwaz9181]

Exactly 👍

[@ΣπυροςΓιαννας-τ9λ]

I'm not saying you are wrong but, this test is incomplete. You verified the capacity. However you didn't verified the 20A load for a period of time which is really important for an ebike or any electric vehicle. From just looking at it the AliExpress one is certainly not original just a copy. Although if it can discharge 10A for example for a period of time without getting too hot it most likely a good copy. But you didn't check. There are many copies now that have the capacity rated but they suck on high current loads. There is a problem if you need high current draw for periods of time. If you don't the copies are fine. The real issue is that it is dangerous because your ebike may catch fire if you using it to the max.

[@kc8adukc8adu63]

lots of resistance in those thin leads and that type of holder is bad too. iirc the capacity on both those assumes a 2.5v cutoff. i normally test at 1a. not sure about the accuracy of your electronic load but some of those are really bad. also note there is a chinese cell (heter) that is often rewrapped to look like an ncrb. the capacity is ok but its still counterfeit. its anyone's guess how long these will last. better to find out before you build that big expensive ebike pack!

[@midomahmoud4700]

Panasonic battery amber ?

[@MiguelDeMarchena]

I get my 18650 from discarded laptop batteries, you can get up to 6 cells and maybe 1 or 2 are damaged or maybe all are good

[@thediyed]

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.

[@ffighter6932]

I'm pretty sure all 18650 Panasonic batteries are made in Japan and not China. So there was my first clue that it was a fake.

[@fredhinck9685]

Says on the battery made in Japan

[@HunGyilok]

@@fredhinck9685 and u belive thst?

[@ryanseidel7436]

Do you have a link to the batteries and discharge tester. Always looking for good supply of real 18650 cells. Thanks!

[@thediyed]

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

[@ryanseidel7436]

@@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

[@busman2050]

Try Battery Junction

[@ErikOdinsvej]

Who is right ? - the people that set the cutoff at 2.5V. or 3.0V. - I see on youtube that some test 18650 battery with different cutoff - then the result will also be different !

[@thediyed]

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.

[@Sekir80]

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

[@cyumadbrosummit3534]

Nice!

[@thediyed]

Thanks!

[@uawsux]

I think your links are broken because it goes to Amazon batteries that are a scam

[@wattsworking2938]

The "panasonic" is most likely a copy, maybe the same as Varicore V-34.

[@thediyed]

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.

[@wattsworking2938]

@@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 👍

[@Stefan-st]

Nice vid But the capacity is 10,152 wh Not 10.000

[@exgenica]

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.

[@Sekir80]

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

[@exgenica]

​@@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.

[@Sekir80]

@@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.

[@kendrajones984]

WOW why make this so complicated, just get a Opus BT - C3100 already. geez, also voltage doesn't tell much on whether there fakes. you could have bought a fake to show the difference.

[@wattsworking2938]

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.