Jerry, I know that I'm two weeks behind in watching RU-vid videos, but here's my vote for seeing your battery tests and the details of *how* you do the testing. I'm certain that I will learn a lot from a "battery testing" video of yours!
I think the cheap unbranded cells coming out of China are the ones that failed QC testing for the branded products. I agree with all of your observations. I also use a Kunkin (thanks to your videos) to test cells and packs. I would certainly be interested in seeing you run some tests. Bad cells are a significant fire hazard, that's why I test them!
I would love to see your tests as I have collection of cells taken from vapes (found in hedgerows) and discarded packs I find in our Local Tesco, as they have a dedicated bin. I find consistently that branded stuff has good cells, what I mean by that is can I find a datasheet for them and do they meet the specs and in the case of Samsung, Panasonic, LG and a few others they always exceed by a little bit. I have opened a lot of Dyson packs but never found Dyson cells in there ! Anyway yes your methods would be interesting. One thing about your last video is that you hinted about problems with Electric cars having batteries made up of hundreds of cells crammed together and should one fail it would be bad news. My question is this 'are the batteries still made this way (individual 18650) or different cells nowadays ? also range will suffer with one duff cell, I realize now how cryptic my comment was in the last vid too ! I also new the video was not a socioeconomic statement either ....cheers
Interesting thing is that when you discharged the battery, BMS cut the power at 12.8V. Isn't that too low? In previous video you stated that lower than 3V per cell will damage them.
I wouldn’t want to use a cell that gets quite hot when charging because of the risk of it catching fire. Li-ion cell fires are nasty and dangerous because you can’t extinguish them.
Not all Chinese brands are bad as stated in your video problem is people buy from scammers off temu or AliExpress I had hit and miss experience from everything from USB memory sticks to batteries at the same time I had good quality too compact drill 18v that holds a charge all day putting shelves up.
If they just put 1.2Ah instead of 4.0Ah there would be no problem. At least you know what your getting. I wonder how many cells are filled with sand. I've seen a tiny vape batttery in an 18650 case with sand in it before. The main problem is you never know what you're going to get
Thanks for the shout out Jerry, I would have had the first comment yesterday but I think it got autodeleted due to mentioning a certain cloud making device. Looking forward to you showing what's inside the cells - probably a lipo scavenged from a used smoking cessation device rattling around in a 18650 sized tin, if it is indeed a lipo!
I certainly agree, and don’t think it’s meaningful to score cheap “political points” towards countries or people. I’m way more interested in _change over time_ - or trends in both large and small contexts of our actual interdependent economy. To me, the battery cells quality change is a symptom of more holistic dynamics, and these “waves” have gone back & forth for… well, always. They simply mirror the realist state of any political economy… …yes, even for batteries…😅
I am curious, were you charging them at 2A? That _might_ be part of the heating issue- you're basically charging the cells at 4C, which.... I think most don't like? I think 1C is the standard safe charging target, but I'm not 100% on what happens when you ignore that. Or it could be that one cell is catastrophically bad, and since the cells are either QC rejects or minimal QC'd it's pulling the rest of the pack down. Just because that one cell is such an outlier I do wonder how the individual cells stack up against one another- if 4 of the 5 have a 1Ah capacity and that one is much lower. But that's getting far to far into the weeds. And, agreed on most of the points- it's kind of fascinating that amazon, ebay, etc have led to this flood of goods which advertise numbers that are physically impossible. (9.9Ah AAs, flashlights with 1 milllion lumens, etc- torque test channel has a nice overview of numbers inflation). I don't think you can justify that as "it's hard to live over there"- I think it's more "that's just how business is done/how you get ahead in the market", and there haven't been any consequences yet. I am curious why/how Amazon tolerates it though- I would have thought they'd be subject to false advertising laws.
People that will argue with a post annoy me. Your first video was excellent, as as an electrical engineer over coffee and breakfast early this may 2nd morning the video hits home hard. The bloke that made the point give the Chinese people a break, they are not the blame, This is a functional and performance series, it's not a philosophical discussion of the oppressed Chinese but rather their govt corruption and allowing these devices to go out of China that are dangerous garbage and junk. Our govt in the US is better maybe than the UK in regulating this junk but not much. Buy tools with quality names like the yellow ones and maybe they will be better.
I assume UK will be better than US. It’s illegal to advertise false specs for products in UK. You also get extra protection by using a UK credit card: if you don’t receive something or it’s not as advertised, you can get the cost refunded by the credit card company. I’m sure seller has to pay return postage cost by law if item is faulty or doesn’t meet its specs. So practically that means: you can buy a cheap battery and if it’s no no good, you get it for free. Because the cost to return it to China would never be worth it, the seller just says keep it when giving a refund.
Like the girl who bought some so called BaByliss hair curling tongs, third of the price, but they overheated( no thermo regulation circuitry), so after the first attempt to curl her hair it was basically seared off. Oh dear, buyer beware😎
If it’s not as advertised, can’t you get a full refund? They potentially shoot themselves in the foot by putting 48V on it. BTW, where do you buy from, aliexpress? As per UK law, I’m sure seller has to pay return postage too. So practically that means: you can buy a cheap battery and if it’s no no good, you get it for free. Because the cost to return it to China would never be worth it, the seller just says keep it when giving a refund. I’m sure if more people got refunds they would soon stop sending crap.
