Review request for HKJ [Rechargeable Batteries]

The holders means I get as close to the battery voltage as possible, even welding strips on would not be better, but might be as good.

I can go up to 120A test current if I did the test manually, but it would require a couple of strips welded to each end of the battery.

Soldering is a bad idea, especially for my testing. I do not want any damage to the CID, the battery must be able to vent.

For the 26800 elements, 30 amperes is enough, and for an additional report in the details of the test, also mention the behavior of the graph of the characteristic of the element at load currents of 40-50A. Although, even 30A will be enough for a normal assessment of these 26800, because you still should not count on their long viability when working on currents even 10A (judging by the available graphs from another tester, for QB26800 the optimal discharge current is a maximum of up to 7 amperes). Everything above these 10A can be considered stress loads, completely unsuitable for their long life.

I did not quite understand what kind of ventilation you are talking about.

1) If we are talking about the possible overheating of the elements when soldering with a soldering iron due to the high temperature, then a high soldering speed and a minimum exposure time of the soldering iron to the poles of the element are required. To do this, at the very beginning it is really necessary to clean the diamond file, having diamond spraying, plus and minus contacts, apply soldering acid and with quick movements of a powerful soldering iron (100-200W) apply tin on the surface of the contacts. Only then should you attach two bare leads from the AWG wires and solder them also quickly. After that, you need to take air into the lungs and just blow into the place of adhesions. It will turn out without overheating. During the tests, the batteries also heat up with high currents, while their internal temperature is much higher.

2) If we are talking about additional air cooling during the test with an air blowing fan aimed at a highly loaded cell, this is not entirely true, because the 26800 cells are designed to assemble large batteries that will be carefully packed in protective films and shirts and at the same time in the real place of their subsequent work they will not see any fans for forced cooling. Then what is the point of such additional ventilation, if the test tests need to be brought closer to the real life of operation, and not only to theoretical?

volchyonok, try DeepL translator sometime, please.

I think HKJ does not want to mess with soldering batteries right now, i.e. he's not interested in soldering batteries. He also said “I do not want any damage to the CID, the battery must be able to vent” because heating the battery anode/plus pole may noticeably increase the chances of damaging the CID. CID is an abbreviature which means Current Interrupt Device:

Related article: Battery Safety 101: Anatomy - PTC vs PCB vs CID @ Battery Bro

P.S: I heartily recommend using a low temperature solder for batteries.

Wed, 12/04/2019 - 11:34

All right, then we’ll all stay in the same place in an endless wait.
It’s not clear how the positive terminal can be damaged if the soldered wires are to be soldered to the uppermost contact, which is located quite far from the dangerous area of the safety valve of the element, and you need to do it very quickly, having prepared in advance for normal soldering? In order for the process to take place in a matter of seconds, you still need to have a powerful 100-150W soldering iron with a copper stinger, a short touch of which will be enough not to heat the entire complex unit. I don’t know, but all over the world even ordinary people do it, i.e. not only masters of their craft.

Self-quoting me back from #748…

I think this was overlooked, so I am asking again. Did those cells arrive home and got tested?

Is it this cell: Test of GTF NCR18650B 3400mAh (Green)

Thanks. What a mess. I see one cell gave ≈3135 mAh at 0.5 A, while the other ≈3321 mAh at the same rate (3228 mAh average at 0.5 A). The shape of the curves matches closely. Do you think this is attributable to cells from different production batches, i.e. an old cell mixed with a new one, or more likely different cell model numbers?

I will not guess about that.

This is due to the fact that elements with a GTF sticker have nothing to do with genuine Panasonic NCR18650B elements. If you carefully look at the positive exit, you will receive evidence of this fact:

Panasonic NCR18650B

GTF18650B

We already know, volchyonok. Those “GTF” cells actually are manufactured by a chinese OEM (BAK, as far as I know), bought in bulk by someone, rewrapped with a fake wrap and then sold. Pretty common in china.

I recently ordered some cheap Colaier G35 cells, their top pole says it all:

An EBD-M05 battery tester is also on the way home, I will publish some discharge curves once I get them.

Apollo Max graphene power bank

https://www.indiegogo.com/projects/apollo-max-the-power-bank-recharges-in-19-mins

I did not understand what level of charging current was selected for this device in order to fill this battery with a capacity of 10 Ah in 19 minutes?

Depends on its battery configuration volchyonok. For starters, it has a 37 Wh rated battery and is powered by 100 W USB PD input so, technically speaking, if both its internal converter and battery were 100% efficient, a fully discharged 37 Wh battery charged at a rate of 100 W would take t = 37 Wh / 100 W = 0.37 hours. This is 22 minutes and 12 seconds so, without any need to refine my estimations even further by taking into account losses, we already now the claimed 19 minutes recharge time must be a lie.

It could also be that the battery capacity is actually lower (a different lie) and it meets the claimed time.

Concerning recharge current a 2S 5000 mAh graphene lithium battery (7.4 V nominal) directly connected to its charging converter would need between 16 and 17 A (I presume) of charging current to go from 0 to 100% in 19 minutes. My quoted range is because it depends on how low the internal resistance of the battery is (should be ultra low).

If the new battery has low internal resistance, then due to its charge with high currents, this resistance eventually starts to increase noticeably, quickly turning the new battery into the old one. Unfortunately this is the case. Long-life batteries turn into fast-discharging capacitors. Therefore, batteries cannot be charged with excessively high currents, and a sufficient amount of time is required for a normal life resource to charge.

The Apollo Max is a gimmick for people who wipe their asses with $100 banknotes. :-))

It is a USB power device and, unless the brand donates a review unit or a bunch of people here (!) raises funds to buy a review unit, no chance to see it reviewed.

I think that such a device will be useful for showing it in feature films when it comes to fantastic action films and when there is not a single extra minute during some scenarios in which everything happens very quickly. It is on the TV screen that people will like how their main characters steal information from their enemies, who, according to the plot of an interesting film, wanted to completely capture all the states completely. However, in one of the scenes, the good guys who will fight the criminals and want to save the world, at a crucial moment, the energy needed to save the USA suddenly ran out. Therefore, they urgently needed to charge their batteries. So, when they plugged it into an outlet, then interested viewers will be able to see how literally in a matter of minutes before their eyes the rescue heroes their battery will quickly charge, because rapidly growing numbers will appear on the display during charging. And after the successful completion of charging, the beloved heroes will finally save all of America. Is this happiness not worth some 100 dollars? :wink:

Vapcell 26650 5300mAh
Supposedly Vapcell has a new 10A capable 14500 that was released early 2020 as well.

Is there a review for the Xtar 4200mAh 21700 battery? (I think Xtar bundled a piece or 2 with the Xtar powerbank/chargers sent for review to HKJ).

I was able to order a few of these when I bought Xtar powerbank (that’s the only way I was able to purchase Xtar batteries — need to purchase an Xtar powerbank/charger and ask them to include batteries with the Xtar powerbank/charger).

They seem to be slim and short — one of the shortest 21700 I’ve encountered (they will fit in a Lii-100 or a ZanFlare C4 charger, where other 21700 batteries do not fit the Lii-100 nor the Zanflare C4). Also, using YR1030 internal resistance tester I got AC IR of 9.5mOhms, which is one of the lower IR values I’ve tested for 21700 batteries (I’ve only tested the Samsung 40T and 30T to have lower AC IR than that Xtar 4200mAh 21700)

It is a very long time since I have reviewed Xtar batteries, they always send one of each type and I need two for a review. I have told them that.