9900 mAh 18650 accumulator

[james_s]

Just put in a claim with ebay, product not as described, forget even dealing with the seller directly. They are selling such obviously fraudulent products that there is no reason go out of your way to resolve things with them before taking official action.

Even 3,000 mAh is pushing it for 18650, anything more than that I would automatically assume is fraud.

[SparkyFX]

Graphene nano blockchain technology for the win! 

I don´t get why mAh should not be an SI-Unit. An Ampere is, an Hour is (3600 SI-seconds).

Of course it is now debatable what the Li-Ion nominal voltage or the cut off should be assumed to be, although somewhat defined by the chemistry. Next is discharge rate and so on.
It is generally accepted that they degrade with charge cycles, so how many would be acceptable..., i guess trade wise it runs down to how many parameters the seller/manufacturer specifies for his product.

Consumer protection might argue that as the compatible equipment and the rest of the market measures in a certain way, everyone offering on the market needs to adhere to that (and is generally advised good to do so) but it is questionable if this survives international trade and definitions in trade agreements.

The sellers biggest fear however is a bad rating...

[wraper]

I don´t get why mAh should not be an SI-Unit. An Ampere is, an Hour is (3600 SI-seconds).

Ah is a vague figure. Does not represent actual energy for which there is watt-hour and Joule (SI). Wh is actually way more meaningful for larger batteries such as 18650 which usually are powering some sort of DC/DC converter. As they draw constant power from an input, not constant current assuming load remains the same while input voltage changes (like when battery discharges).

[metrologist]

I don´t get why mAh should not be an SI-Unit. An Ampere is, an Hour is (3600 SI-seconds).

Ah is a vague figure. Does not represent actual energy for which there is watt-hour and Joule (SI). Wh is actually way more meaningful for larger batteries such as 18650 which usually are powering some sort of DC/DC converter. As they draw constant power from an input, not constant current assuming load remains the same while input voltage changes (like when battery discharges).

I lost track of this when https://www.bipm.org/en/measurement-units/

[FrankBuss]

Probably Ah is not a SI unit, because there is already a SI unit which measures this: 1 Ah = 3600 C (coulombs). So it doesn't make sense to use Ah for it. Of course, using "C" would be confusing for accus, because there is already a "C" rating which means something totally different. I guess marketing is responsible for all this mess, they don't know much about physics or SI units.

BTW, someone tested a lot of 18650 accus:

http://danyk.cz/test18650_en.html

There are a few with the label "GIF", but in different colors than my version. He measured about 550 mAh for them. So I'm sure now I did measure it right.

[FrankBuss]

I left a negative feedback for the seller. This accelerated the process a bit He offered me to refund half of the price. Of course I refused and answered that we can wait until eBay solves his scam auction.

[OwO]

taobao > aliexpress > ebay.

If you search "18650" on taobao you will see all the inflated capacity listing are now gone. I dug for awhile and only found this: https://item.taobao.com/item.htm?id=545253068656&ali_refid=a3_420434_1006:1103697496:N:3FBOsCTSfhb8q8nVEGLCiw%3D%3D:b316254cfe23009afb537ce87e2a8b9f&ali_trackid=1_b316254cfe23009afb537ce87e2a8b9f&spm=a230r.1.1957635.65
In the description it even says "printed 4800mAh, actual capacity 1200mAh". I think there's been some crackdowns and taobao is now much stricter on items being as described. I've bought 18650s on taobao and so far all passed capacity tests.
Unfortunately aliexpress is still riddled with fake lithium battery listings.

If you have access to taobao and want the best bang for buck 18650 cells, search "特斯拉 18650" ("tesla 18650"). These are around 3000mAh and cost 13yen ($2 USD), and have very similar characteristics to the NCR18650B.

[FrankBuss]

Thanks, but buying from Taobao is expensive for me because of the extra handling fees from yoybuy. But I reported the auction on eBay now as well as fraud. Unfortunately couldn't add any description to the report, and couldn't find any contact to eBay where a human is on the other side, so difficult report all these cases. And I bought a few others from eBay, some looks legit with reasonable ratings. Will report here again which one are good and which are scams.

[OwO]

I think there are real NCR18650B listings on aliexpress, but you have to be careful and be sure to read the 1 star reviews first. I once bought some NCR18650Bs from aliexpress when I lived abroad, and the capacity mostly checked out (measured between 3100 - 3200mAh). I would not bother trying the no-brand or "XXXX-fire" branded cells. Those are guaranteed to be mislabeled (taobao listings of *fire cells all state real capacity is not labeled capacity).

[SiliconWizard]

Again, note here that it's not just outrageous mislabelling here, which would be bad enough.

The batteries are not EVEN close to regular 18650 Li-ion batteries, their construction is pure shit. This is double rip-off. Unbelievable.

So even if they had been labelled more conservatively with a 3000mAh figure or so, which would have been average for this battery format, this would still have been complete rip-off.

[amyk]

BTW, someone tested a lot of 18650 accus:

http://danyk.cz/test18650_en.html

There are a few with the label "GIF", but in different colors than my version. He measured about 550 mAh for them. So I'm sure now I did measure it right.

Interesting that the no-name "bland" cells seem to be far more honest in their ratings and a surprisingly good value; the completely unbranded 2000mAh one for $1.50 was actually 2391mAh(!), almost 20% more than advertised.

Again, note here that it's not just outrageous mislabelling here, which would be bad enough.

The batteries are not EVEN close to regular 18650 Li-ion batteries, their construction is pure shit. This is double rip-off. Unbelievable.

So even if they had been labelled more conservatively with a 3000mAh figure or so, which would have been average for this battery format, this would still have been complete rip-off.

Like I said above, these are relabeled 400-600mAh 18650s. They are intended to be ultra-cheap cells for solar garden light applications, where a higher capacity would be useless.

[IanB]

Like I said above, these are relabeled 400-600mAh 18650s. They are intended to be ultra-cheap cells for solar garden light applications, where a higher capacity would be useless.

Unfortunately they also seem to be treated as a disposable item--I saw that some garden lights try to charge them with a direct current loop from the solar cell without any charge control or high voltage cut-off. While this worked fine for nicads it is not so fine for lithium cells and the cells tend to die after a year. Here higher capacity might even be better as there is less chance of the cells being overcharged before sunset.

[SiliconWizard]

Like I said above, these are relabeled 400-600mAh 18650s. They are intended to be ultra-cheap cells for solar garden light applications, where a higher capacity would be useless.

Alright; but whether they are "genuinely" intended for garden lights, that doesn't make them any less crappy probably. (I don't really see the point of using such a format for such a low capacity anyway, but that's beyond the point...) And getting the idea of selling them as ultra high capacity batteries is just ridiculous.

Relabeled batteries with a x2 - x3 inflated figure is bad enough, but more common. Here we have an almost 25x factor. That's just unbelievable.

Of course, as others have said, anyone actually believing that the displayed capacity could even be possible, can only be angry against themselves here I guess. But my point was that they still could have expected a typical capacity for this format, instead of the lowest cheap stuff you could imagine. But moral is, never even underestimate the "capacity" (as opposed to that of the batteries) of those sellers to make fun of you!

[ledtester]

For a battery load tester, you can do a lot worse than an EBD-M05:

eBay auction: #283107190979

One I can recommend:

https://www.banggood.com/Original-ZHIYU-60W-110W-9_99A-30V-Constant-Current-Electronic-Load-Aging-Battery-Capacity-Tester-p-1146280.html?rmmds=search&ID=529811&cur_warehouse=CN

60W version for $20, 110W for $25.

You can find the same items on ebay for a few dollars less, but you probably won't get the same customer service. Banggood sent out a replacement unit when something I bought arrived DOA, and then refunded my money when the replacement was also defective.

[PlainName]

Good to hear that Bangood have decent customer service (even though they do  £==$ pricing conversion). I fortunately haven't had to take advantage yet, but I'm sure the time will come...

[kjr18]

With brand names like "ever fire" and "Rakieta" (sounds a bit like rocket)... my trust is very limited :-)
But it reminds me to finally acquire an electronic load, i figure the amount of broken battery packs for e-bikes, e-scooters and so on will either require some refurbishing or at least cheap sources for good batteries. Might need to build a spot welder too...

Funny thing, "Rakieta" literally means rocket in polish, so not really sounds a bit like, rather it's the same.

Well, if you need genuine Panasonic 18650 cells, ebay or AliExpress are not places where you should look for them. One time when I was just looking at "more to love" on AliExpress app's homepage I found this seller that sells battery wraps and many other things for making battery packs. What's wrong with selling battery wraps, you might ask? Well, it's fine unless they look just like that

[OwO]

I'm not aware of any Chinese manufacturers of 18650s that reach 3000mAh, so if they show >= 3000mAh on the tester then it's most likely the tesla cells or NOS panasonic cells. Both are based on the same construction and have the same charge/discharge curve.

[FrankBuss]

I dug out my GPIB adapter for my Fluka 8842A and updated my logging script, which I developed for the Rasbperry Pi logging project for voltnuts. I managed to install the script now on my main desktop PC, which is running most of the time anyway, so no need for the Raspberry Pi anymore. Then I discharged it again with 0.1 A and logged the voltage every 10 seconds:



It bounces back a bit at the end when the load is turned off at about 2.9 V, but doesn't get higher than 3.2 V. But now the capacity is a bit higher with 549 mAh, nearly exactly the same as the other guy measured for the GIF brand. I guess he used the same low discharge current, because when discharging with 0.5 A, then the capacity is not as high as with 0.1 A, which is expected. Here is the Google sheet for all the logged data, all formulas, and the diagram.

I got the Rakieta batteries as well (fast shipping because shop in Germany). Will test it now.

[metrologist]

Expect the marketers to use your chart to express battery life in hours 

Can't wait for the next install...

[FrankBuss]

The "RAKIETA" measurement is done. As expected, not 12000 mAh, but at least a bit better than the garbage GIF battery: 1502 mAh:



Looks like the material is different, because the curve looks different and lower voltage.

Refund request sent.

[SiliconWizard]

The curve is interesting. For a typical Li-ion battery, especially at this relatively low discharge current vs. capacity, I would expect a somewhat steeper initial decrease and then a bit more flat once voltage has reached 3.6-3.7V. It's almost linear from 4.1V down to 3.4V. Weird.

[FrankBuss]

The curve is interesting. For a typical Li-ion battery, especially at this relatively low discharge current vs. capacity, I would expect a somewhat steeper initial decrease and then a bit more flat once voltage has reached 3.6-3.7V. It's almost linear from 4.1V down to 3.4V. Weird.

I guess if they lie about the capacity, they might not use the best materials either, which could lead to strange curves. Or maybe it is an old refurbished laptop cell. Sometimes they even claim that they have overcurrent etc. protection, but some Youtube reviews show that they don't have it.

Now the question is, how could this be stopped? Obviously eBay doesn't care, they just refund the money with buyer protection and the shop continues to sell them. Maybe if everyone who could measure the capacity would buy one, then claim a refund and leave a negative feedback, would stop these shops There are cheap battery capacity tester for like $20 on eBay as well.

[SiliconWizard]

I guess if they lie about the capacity, they might not use the best materials either, which could lead to strange curves. Or maybe it is an old refurbished laptop cell. Sometimes they even claim that they have overcurrent etc. protection, but some Youtube reviews show that they don't have it.

This could typically be explained if they used coke as an anode material (instead of graphite), which is pretty cheap and was used in earlier Li-ion batteries.

And yes, it's quite common that those crap batteries don't have ANY embedded active protection.

[IanB]

The curve is interesting. For a typical Li-ion battery, especially at this relatively low discharge current vs. capacity, I would expect a somewhat steeper initial decrease and then a bit more flat once voltage has reached 3.6-3.7V. It's almost linear from 4.1V down to 3.4V. Weird.

If I compare with discharge curves published by Panasonic, Sanyo, Sony etc. it doesn't seem all that strange. In fact, it looks quite typical to me.

[FrankBuss]

The drama continues. Message from today from the seller of the 9900 mAh GIF accumulator with the 500 mAh capacity:

Dear buyer,

Sorry for all the troubles.
Could we FULL refund you as the compensation,and can you help us change the feedback to positive?
You know we are trying to be a good seller.The feedback is very important for us.Your surport and help will keep us moving forward and constantly improving our service.
If you agree, we will send you the Request Feedback Revision asap.
Highly appreciate for your understanding and help.

Waiting for your soon reply.

Best regards

So probably this is the reason why there is no negative feedback with the battery capacity as the reason. My answer:

Sorry, I can't give you a positive feedback, because you are still selling this shit in your shop, and scamming other customers of eBay. The feedback system helps to prevent people like you from doing such things, because then the other potential buyers can see what you do. If everyone would do this, I would not have bought it in the first place and less trouble for everyone.