Author Topic: Chinese battery capacity tester and batteries  (Read 27439 times)

iloveelectronics

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Chinese battery capacity tester and batteries
« on: October 30, 2013, 10:35:41 AM »
This is not exactly a review but I just wanted to share this little gadget I found from China. Martin mentioned in his T4D#76 that I was going to look at some of these low cost battery capacity testers (as oppose to his fancy thousand dollar analyzer). I finally got a little time today to have a quick play around with this one. I am very happy to report that it seems to do a fine job of what it's designed for.

The device requires a 12V power input, and allows you to set a discharge current anywhere between 0.1-2.4A, and a cutoff voltage between 0.1-6V. It has a 4-digit 7-segment LED display that shows you the voltage, discharge current and the cumulative capacity in mAH. You cycle through these 3 values by pushing a button. As soon as the voltage drops to the set cutoff voltage, the discharging stops and you can see the capacity of the battery. Very simple.

It even has a USB port that connects to the PC through a provided USB-TTL cable (with a Prolific chipset inside it seems), and has a software (in English too!) for data logging, graph plotting, controlling the device and firmware upgrade, etc.

I tested two 3.7V Li-ion 14500 batteries from the same source in China rated at 750mAH capacity, discharging at 1A and 0.75A and both reported similar result of around 785mAH.

I also tested a NCR-18650B (supposedly made by Panasonic, or at least the actual internal cell) that looks like this: http://www.amazon.com/Panasonic-NCR18650B-Protected-Rechargeable-Batteries/dp/B00AW1IUVS It claims 3400mAH capacity. At 1A discharge current I got a result of over 3200mAH, close enough.

This little device looks like something I might consider adding to my store in the future :)


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Email: franky @ 99centHobbies . com

SeanB

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Re: Chinese battery capacity tester and batteries
« Reply #1 on: October 30, 2013, 01:25:57 PM »
Nice, might be a good thing to add to my order.

retiredcaps

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Re: Chinese battery capacity tester and batteries
« Reply #2 on: October 30, 2013, 01:54:03 PM »
This little device looks like something I might consider adding to my store in the future :)
Any idea on price?

iloveelectronics

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Re: Chinese battery capacity tester and batteries
« Reply #3 on: October 30, 2013, 02:02:40 PM »
Any idea on price?

I still need to work out the exact costs but I believe it will be somewhere around the mid to high $30's.
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iloveelectronics

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Re: Chinese battery capacity tester and batteries
« Reply #4 on: October 30, 2013, 09:45:03 PM »
Any idea on price?

I still need to work out the exact costs but I believe it will be somewhere around the mid to high $30's.

Let's just make it $35 for forum members, worldwide shipping (regular air mail, no tracking) included. I haven't got any in stock yet though, it will take another week or 2.
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dr_p

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Re: Chinese battery capacity tester and batteries
« Reply #5 on: October 31, 2013, 07:02:02 AM »
How does it stack up against this type of universal battery charger/discharger?

I used to have one of those and was very pleased with the functionality. Charge/dischargecycle at selectable current, mAh counter display, Li-Ixx, Pb, Ni-xx, selectable nr of cells. No USB interface though.

There seems to be a TTL serial PC interface with software for it.
« Last Edit: October 31, 2013, 07:05:30 AM by dr_p »

iloveelectronics

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Re: Chinese battery capacity tester and batteries
« Reply #6 on: October 31, 2013, 08:03:32 AM »
How does it stack up against this type of universal battery charger/discharger?

I used to have one of those and was very pleased with the functionality. Charge/dischargecycle at selectable current, mAh counter display, Li-Ixx, Pb, Ni-xx, selectable nr of cells. No USB interface though.

There seems to be a TTL serial PC interface with software for it.

I don't know to be honest, because I've never used one of those. They have always looked too complicated to me, too many pins/connectors/settings etc. I was searching for a simple solution to test my 18650 and 14500 batteries' capacity and that's how I found that device. I suppose these RC chargers/dischargers would offer more bang for they money due to their multiple functions and lower pricing from mass production, but I really like the simplicity of my device and the possibility to tinker with it. For example, the board is actually designed to allow adding a cheap 5V-12V DC-DC booster so you don't need the 12V input and can just power it from the USB port.

EDIT: Just found out that most of the cheaper RC chargers/dischargers don't actually do discharge current over 1A, ones that do are quite a bit more expensive. One more plus for my little thingie  :P
« Last Edit: October 31, 2013, 09:52:42 PM by iloveelectronics »
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dinoboy

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Re: Chinese battery capacity tester and batteries
« Reply #7 on: December 30, 2013, 06:17:49 PM »
The designer and manufacturer is ZKETech and i think that they're also on Alibaba, Aliexpress, or Taobao.

Software download FREE: http://zke2006.blog.163.com

I am into chargers and stuff and i would be interested in having such a thing for reference purpose.

EDIT:
I'm soliciting EBC-A which is the oldest and therefore most often sold product from their catalog. The EBD-Mini is a new model, smaller, and not much cheaper. In addition to discharging, EBC-A can also charge cells, which will result in more interesting graphs to look at on the PC screen. Basically EBC-A is a hobby charger without balance charging function, just cheaper or more modest in its build. It is questionable if these Chinese dischargers can measure more accurately than dedicated hobby chargers. For sure, the primary purpose of hobby chargers is to balance charge and not to discharge individual round cells lol.

EDIT2:
if the product is good and enjoy it (for some particular reason) a lot, then i'd feel motivated and (might) even open my own review thread on EBC-A in future. FYI even if the product turns out to be accurate and consistent, my aim is not to get you (the reader!) into buying this exotic product too. the purpose of my review would be an informal showing off of the product la "look what i have, look what it does, pretty funny and not two shabby huh?", with very little photo material, to have some reference out there in the WWW. i have googled, didn't see any EBC-A review on the net (in English language or other ..), so it does make some sense to discuss the product in detail .. out of curiosity and joy.

EDIT3:
frisr Tue, 2014-02-25
frisr Mon, 2014-04-28
For illustration purposes, please see below photos of my EBC-A in action with the battery holder. I placed the device upon my white PC which is located in a corner of my room where it can work peacefully with nobody accidentally touching the stuff. This is important enough because the USB cable is very loosely connected to the device in the female jack and in future i should buy a better male plug. Clearly, the company should have fitted the USB cable with some better (original) male plug for better connectivity between board and wire.

You can see the three interface connections, they are all of basic nature:
  • 12V DC power adapter
  • crocodile clips for battery connection
  • USB cable for PC link connection


Once you connect the device to the PC *and* establish the actual communication between the devices through the PC software UI, the device would display "-PC" in the lower right corner of the digital display. From that point on, all 4 buttons of the device are deactivated and the device can only be controlled through/from/by the PC software!


The following is an okay setup solution for small/middle-sized cells. I had ripped out the electronics and connections of the Ultrafire charger[RIP] so that it could be used as battery holder. Its golden-looking (brass?) metal contact plates should have sufficiently low electrical resistance and be a good substitute for neodymium. The crocodile clips/cables which were provided with the purchase are very thick and of nice quality. With this setup i got "0810mAh" for the cells.


"Pix or didn't happen" lol that's what was said to me once, so here a pic of the final minute of test5 ,

(click to enlarge!)

animated gif, sorry for the bad pic quality, i tried different photo shooting angles:

« Last Edit: April 28, 2014, 12:22:13 PM by dinoboy »
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dinoboy

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Re: Chinese battery capacity tester and batteries
« Reply #8 on: January 31, 2014, 11:08:37 AM »
EDIT:
I'm soliciting EBC-A which is the oldest and therefore most often sold product from their catalog.

All right, i got the EBC-A "v2.2.0, 13-07-01" (apparently meaning July 1st 2013) delivered today and i've started some basic functionality tests, CHARGE and DISCHARGE. The PDF manual is a joke but the device is straight forward to use, veely similar to a typical hobby charger (without balance function):
you setup the most basic parameters of your program and run it!

I have connected the device through the USB cable to my PC with installed English software but don't get too far. First, my PC asks for a driver for the new USB-hardware. I don't know which driver to install, there was no CD-ROM included. Second, the PC software clearly looks for "COM1", not USB. COM1 is serial port. Basically i am doing something wrong lol. There has to be some (optional) serial cable which i didn't buy. Well, thinking about it, i don't really need the PC software and graphing. I'll ask the maker if he can ship a FREE serial cable or USB driver or whatnot.

I am primarily interested in the accuracy of the device at discharge tests, that's what this thread is about ("Chinese battery capacity tester"). For this, i'll do a series of repeated(!) discharges of known quality cells (Panasonic-Sanyo: Eneloop AA, Eneloop AAA, NCR18650A, NCR18650B, UR14500P, a.o.). My other known reference is Maha Powerex MH-C9000. When i come to the conclusion (hopefully!!) that the device is amazingly accurate, at least matching Maha's accuracy, then i will certainly record the data and use it for my future work of evaluating/assessing other new chargers such as the so-called dreamchargers.

Charging seems to work beautifully, on my ET3100 connected with a pair of crocodile clips and neodymium the EBC-A terminated the cell at 4.198V offline voltage; termination current in the CV-phase was "00.04A" jumping towards "00.03A", so that could have been 35mA, which is very low and nice for a LiIon charger. But as i said, i am not too interested in the charging capabilities of the device.

I'll post my discharge test results in this thread. It's a great place to keep record of them.

EDIT:
i figured it out with the installation of the driver.. see attached
« Last Edit: February 02, 2014, 07:42:22 PM by dinoboy »
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dinoboy

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Re: Chinese battery capacity tester and batteries
« Reply #9 on: January 31, 2014, 12:25:44 PM »
test1.x-series: This post is about discharge tests with my 10440's.



Parameters, tentative:
  • starting voltage: fully charged, 4.200V+ offline
  • program: "DCHG 00 NOR 100W", i.e. Discharge Test
  • discharge rate: "00.20A", i.e -200mA
  • target voltage: "02.80V", i.e. 2.80V

my historic reference values from genuine Imax B6, with 3.00V cut-off voltage and -100mA discharge rate:
grey protected UF10440, marked cell: 254mAh (repeated tests: 261mAh, 260mAh), or more typically: 245mAh
grey protected UF10440, unmarked: 225mAh (repeated test: 229mAh)
blue unprotected UF10440, marked cell: 334mAh (repeated test: 338mAh)
blue unprotected UF10440, unmarked: 278mAh (repeated test: 282mAh)

my EBC-A results:
test1.1: grey protected UF10440, marked cell: "0240mAh"@-200mA/2.80V
test1.2: grey protected UF10440, unmarked: "0199mAh"@-200mA/2.80V
test1.3: grey protected UF10440, marked cell: "0253mAh"@-100mA/3.00V
test1.4: grey protected UF10440, unmarked: "0212mAh"@-100mA/3.00V
test1.5: (test1.3 repeated): "0258mAh"@-100mA/3.00V
test1.6: (test1.4 repeated): "0212mAh"@-100mA/3.00V
test1.7: (test1.3 repeated again): "0256mAh"@-100mA/3.00V
test1.8: blue unprotected UF10440, marked cell: "0345mAh"@-100mA/3.00V (starting from 4.21V)
test1.9: blue unprotected UF10440, unmarked: "0246mAh"@-100mA/3.00V
test1.10: (test1.8 repeated): "0328mAh"@-100mA/3.00V (starting from 4.17V)
test1.11: (test1.9 repeated): "0250mAh"@-100mA/3.00V
test1.12: (test1.3 repeated and logged): "0258mAh"@-100mA/3.00V

comments on the above tests:
test1.1: that's lower than Imax B6 result (~240 < ~260). Given that the cell is exactly 24 months old and discharging at double the rate, the number is plausible. promising result!
test1.2: shows consistency because Imax B6 result was lower too! promising.
test1.3: to get directly comparable data, let's adopt Imax B6 parameters. lol, missed the Imax B6 reading by 1mAh (253 vs. 254), fantastic result. promising!!
test1.4: sounds plausible (212 vs. ~227) because of cell abuse and capacity degradation. in all fairness for sure we're going to repeat test1.3&1.4 because we did the same 2yrs ago with Imax B6 tests. no doubt the Imax B6 data isn't the best reference simply because it is 2yrs old data. so when done with the 10440's tests, our next post will be on new Eneloop AAA for which we have a fresh reference: C9000 data!!
test1.5: higher than test1.2 (258 vs. 253) but definitely in the range of the Imax B6 data, i am impressed. cell degradation over the 2yrs should have been higher but maybe this is simply a good cell! test1.6 will be interesting now.
test1.6: un****ingbelievable, it's the same result as test1.4!! this is the first real indication of accuracy (or say, consistency) of the device. it would also mean, in theory, that in future i would not have to repeat tests again to ensure data integrity. let's repeat test1.3 (=test1.5) again for a final word on this preliminary promising result.
test1.7: totally plausible (256 vs. 258). i am really beginning to like the performance of this thing!! from this test result it becomes clear that in practice i could have saved the repeated tests because the device returns the same mAh-reading for the identical cell. we will use this knowledge in future tests where we don't repeat the identical test for each and every cell. next up, let's try to measure the max capacity of my pair of unprotected blue UF10440's. That's a true challenge because the cells are abused and only 1 of my chargers, DC1, is able to get them to 4.200V after repeated re-insertions; other li-ion chargers terminate these poor cells at 4.11V or so. The cells suffer from superhigh self-discharge rate at the 4.20V level. Since the cells are so poor, it wouldn't make sense to measure their max capacity; on the other hand, since we have Imax B6 reference data, i am curious to learn how far off the capacities are after 2yrs of abuse in power LED flashrights! Depending on the result, i might repeat the test1.8, but i guess not. We should proceed to Eneloop tests soon imho.
test1.8: wow, this is totally unexpected, the value is higher than Imax B6 (345 vs. ~336). instead of repeating the test, for now let's go over to test1.9, that is the other blue 10440 and see what comes out! Something's off here. Not by much, but let's note it.
test1.9: looks plausible enough (246 vs. ~280), capacity loss after 2yrs of abuse. for the sake of completeness, i'll repeat the test in test1.11
test1.10: i could hardly get the voltage to the 4.20V target. value is lower than test1.8 (328 vs. 345), oh well. it's an abused cell and not suitable for reference purposes.
test1.11: wow, fantastic result (250 vs. 246). this really confirms my conclusion from test1.6: if one is able to create identical test start conditions (which will be a challenge with Eneloops!), then a single test run is needed to get a fairly accurate and consistent mAh-capacity reading for the cell under inspection. in theory it'd be a waste of time (from now on) to repeat identical tests. I had 4pcs of 10440's. In the above series of test runs i tested each cell at least twice in order to be able to draw some conclusions on charger's tendency with respect to consistency and accuracy. I am done with testing 10440's and up to this point, we already have a good picture of this device's performance.
test1.12: meanwhile i figured out how to install the driver and get the PC software working. using neodymium was never my preference, so i tried a diy battery holder and redid test1.3 in order to see if the changed electrical resistance (metal contact plates instead of neodymium) altered the test result. see attached screenshot, i got the same value again (258 vs. 253/258/256), absolutely fantastic! this makes my life of testing small cells much easier because a battery holder holds the cell in place! For big cells, e.g. 18650's, the diy battery holder isn't too comfortable and involves some fiddling, so i might still revert to neodymium for them. In any case, i am confident now of EBC-A's performance (i.e. accuracy and consistency) and ready to proceed to the more challenging (or say time-consuming) tests: Eneloop!!

Summary:
The EBC-A tends to deliver amazingly consistent  mAh-readings, as consistent as the Imax B6 readings. This can only be possible, if the device is also accurate. Very accurate (for the price paid; it costs half the price of a genuine Imax B6!). Our next step to knowledge and wisdom is to compare the reading to an absolute mAh-reference scale. For this, we take new (and also old) 3rd gen Sanyo Eneloop AAA/AA (rated nominal 800/2000mAh) and their mAh-readings off the Maha MH-C9000. I already know the 'C9000-capacities' of these Eneloop test cells and the exact conditions under which i produced them, so i could comment on the EBC-A readings right away and interpret them with confidence.

So far, my C9000 was the only reliable battery analyzer in my household (i had given away my Imax B6!). My hope is that i can replace it by the EBC-A as battery analyzing tool because C9000 can analyze NiMH chemistry only and it accepts only NiMH cells with low internal resistance. My personal C9000 unit is very consistent and very accurate, i established this as fact already. Am looking forward to the Eneloop tests from tomorrow on!!

My motivation is: Knowing the exact real actual capacity of cells helps me (the tester and experimenter) to evaluate the quality or assess the performance of other products with battery analyzing feature, such as the forthcoming dreamchargers. The point is the question: Can the inexpensive battery analyzer EBC-A replace expensive proven high-quality analyzers such as
  • genuine Imax B6
  • Jun-si iCharger
  • West Mountain Radio CBA IV
  • Handheld Scientific BA-1
  • Schulze chargers
  • a. o.

We'll find out. Next up are Eneloop tests!

« Last Edit: March 31, 2014, 07:43:51 AM by dinoboy »
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dinoboy

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Re: Chinese battery capacity tester and batteries
« Reply #10 on: February 03, 2014, 09:43:25 AM »
test2.x-series: This post is about discharge tests with my Eneloop AAA's.

I bought them in Dec '13 and didn't use them much other than for testing them in 4 independent accurate and mutually consistent channels <C1, C2, C3, C4> of the C9000 (and dreamchargers), repeatedly. I ran several R&A's (Refresh&Analyze) and also Break-In. See below a compiled table with my first runs and last runs:
Eneloop AAAcell#1cell#2cell#3cell#4
Refresh&Analyze1C1: 766C2: 769C3: 772C4: 766
Break-In1C1: 807C2: 803C3: 808C4: 809
Refresh&Analyze2C1: 818C2: 815C3: 823C4: 822
Refresh&Analyze3C1: 811C2: 808C3: 817C4: 815
Refresh&Analyze4C1: n/aC2: 803C3: 820C4: 817
Disch
Refresh&Analyze5C1: 804C2: 810C3: 801C4: 796
Disch
Refresh&Analyze6C1: 801C2: 808C3: 799C4: 794
Disch
Refresh&Analyze7C3: 798C4: 799C1: 798C2: 798
Refresh&Analyze8C3: 813C4: 814C1: 813C2: 814
Disch
Refresh&Analyze9C2: 809C1: 800C4: 801C3: 792
Disch1C2: 797C1: 792C4: 794C3: 786
Refresh&Analyze10C1: 810C2: 817C3: 805C4: 798
Refresh&Analyze11C1: 809C2: 815C3: 806C4: 802
Note: Disch1 was not the first discharge on the cells. As you can see above, there were 4 further discharges (in dreamchargers) between R&A4 and R&A9. For for our purposes i am listing only from the 5th discharge on and calling it "Disch1".

Between the completed runs of the Refresh&Analyze program, i left the cells many hours untouched, 10-36hrs, to reach some sort of equilibrium state or 100%(?) stationary condition in the channels of C9000. In theory, that's the state where the Eneloop cell is in equilibrium with/by the 10mA trickle charge. Since such a hypothetical equilibrium might not exist, it is not fair to compare data across rows. One must compare data between columns of the same row to get an indication of "consistency", for example R&A10 indicates that
cell#2 > cell#1 > cell#3 > cell#4

and R&A11 indicates the same
cell#2 > cell#1 > cell#3 > cell#4

And to our amazement, there is minimal (albeit inconsistent) variance between the values of the 2 runs. And since the variance is minimal only, i would conjure up the notion of accuracy: In my perception, my C9000 unit has GOOD accuracy and VERY GOOD consistency. And it certainly helps to repeat R&A on the 4-pack of cells whenever possible to reconfirm the consistency of the (cell#2>#1>#3>#4)-relation or mathematical inequality.

Now we're ready to proceed with the EBC-A tests! And this time we're logging all runs with the EBC software.

Parameters:
  • cell type: new Eneloop AAA HR-4UTGB, i.e. 3rd gen Eneloops
  • starting voltage: fully charged in C9000 as described above, may be anything between 1.46-1.49V!!
  • program: "DCHG 00 NOR 100W", i.e. Discharge Test
  • discharge rate: "00.20A", i.e -200mA which is 0.25C
  • target voltage: "00.90V", i.e. 0.90V

my EBC-A results:
test2.1: cell#1: "0810mAh"@-0.20A/0.90V
test2.2: cell#2: "0810mAh"@-0.20A/0.90V
test2.3: cell#3: "0810mAh"@-0.20A/0.90V
test2.4: cell#4: "0807mAh"@-0.20A/0.90V

comments on the above tests:
test2.1: looks perfect. the same as R&A10 and R&A11. drum rolls, test2.2 will give us some further indication as to the accuracy of EBC-A with respect to C9000. note that in the shared pic the number is '811' but let me call it a bug that the mAh-counter isn't reset to 0mAh even after exiting the software wtf, so it said 1mAh when i started the program and added to the number from there on! you'll see the same distracting thing in pic of test2.2 where the counter started from 811 on. basically what we have to do is substracting 811 from the result of test2.2. and for the future tests i need to find a way to reset the mAh's in the EBC software. sorry for the inconvenience, i am still new to all this!
test2.2: 1621-811=810. the same as cell#1. hmm. *if* the C9000 is accurate *and* the EBC is accurate too, then this value should have been higher imho. or, they are indeed the same because of the forced equilibrium state; in fact, the cells have been sitting in the C9000 for 48-72h straight. in any case, without further tests, it is impossible to tell with 100% certainty why EBC measures exactly the same capacity for both cell#1 and cell#2. rest assured, i've already inserted the cells back in C9000 for a R&A12. with repeated tests under identical perfect test conditions we should be able to find out which device is more accurate and consistent.
test2.3: again 810, wtf! maybe it was/was not a good idea to test new cells for the identical production batch? in the next test-series i'll be testing old Eneloop AA's with *definite* capacity differences. at this point i am getting the feeling that EBC-A may be slightly more accurate than C9000  :o
test2.4: good result. Except for R&A8, the R&A5R&A11 indicated that cell#4 had always the lowest capacity of the 4-pack, no matter in which C9000-channel it was tested. So i am not too surprised that the EBC-A device did not measure "810 again". in fact, i should have been more surprised if it had measured 810 instead of this slightly lower number!

Are we done with Eneloop AAA tests? Not yet. As mentioned, i am doing a R&A12 right now (starting from discharged state!). Then i'll do another run, R&A13, i.e. starting from fully charged state! Then i'll let the cells rest in the C9000 for 2-3 days in order to reach the same condition when we started the test2.x-series. Then i'll discharge the cells in the very C9000 (Disch2), which is similar to what i did in R&A9 followed by Disch1. C9000 R&A-values are usually higher than Disch-values because the R&A-program starts the discharge routine 120min after "resting" at fully charged state. During these 2hrs the C9000 still pumps top-off charge (and trickle charge), which you can see by the rising voltage, so by the time the Rest-routine is completed, the cell voltage may be at 1.51-1.52V instead of 1.47-1.49V. That's why rows of R&A's are only 100% comparable if the initial cell conditions were the same, e.g. fully charged states, at the time when the R&A program was launched (compare for example R&A7 with R&A8 where the former was preceded by a discharge program).

my continued C9000 & EBC-A tests:
test#.#Eneloop AAAcell#1cell#2cell#3cell#4
tests2.1-4DISCH1 -0.20A/0.90VEBC: 810EBC: 810EBC: 810EBC: 807
test2.5Refresh&Analyze12C1: 801C2: 810C3: 802C4: 793
test2.6Refresh&Analyze13C4: 817C3: 812C2: 820C1: 805
test2.7Disch2 -200mAC2: 800C2: 802C2: 798C2: 800
test2.8Refresh&Analyze14C1: 793C4: 801C3: 798C2: 796
test2.9Refresh&Analyze15C1: 818C4: 819C3: 815C2: 816
test2.10DISCH2 -0.20A/0.90VEBC: 813EBC: 814EBC: 812EBC: 802
test2.11Refresh&Analyze16C1: 794C2: 804C3: 801C4: 792
test2.12DISCH3 -0.20A/0.90VEBC: 812EBC: 808EBC: 808EBC: 800
test2.11Refresh&Analyze17C1: 797C2: 803C3: 801C4: 791
test2.12Refresh&Analyze18C2: 816 (1mAh)C2: 816 (15mAh)C2: 813 (??mAh)C2: 808 (9mAh)
test2.13Disch3 -200mAC2: 797C2: 801C2: 799C2: 789
test2.14CHARGE------------
test2.15Refresh&Analyze19C1: 806C2: 811C3: 800C4: 796
test2.16Refresh&Analyze20C1: 813C2: 818C3: 807C4: 805
test2.17Refresh&Analyze21C1: 817C2: 822C3: 815C4: 809
test2.18Refresh&Analyze22C1: 814C2: 819C3: 808C4: 806
test2.19Disch4 -200mAC1: 791C1: 789C1: 788C1: 786
test2.20Refresh&Analyze23C1: 795C1: 795C1: 793C1: 787
test2.21Refresh&Analyze24C1: 815C2: 808C3: 803C4: 785
test2.22Refresh&Analyze25C1: 812C2: 806C3: 804C4: 791
test2.23Refresh&Analyze26C1: 808C2: 802C3: 799C4: 786
test2.24Refresh&Analyze27C1: 798C2: 792C3: 789C4: 776
test2.25Refresh&Analyze28C4: 795C3: 801C2: 800C1: 799
test2.26Refresh&Analyze29C4: 798C3: 802C2: 799C1: 796
test2.27Refresh&Analyze30C4: 795C3: 801C2: 799C1: 798
test2.28Disch5 -200mAC4: 771C3: 776C2: 773C1: 772
test2.29Refresh&Analyze31C4: 782C3: 787C2: 786C1: 784
test2.30Disch6 -200mAC1: 764C1: 758C1: 761C1: 756
test2.31DISCH4 -0.20A/0.90VEBC: 795EBC: 797EBC: 794EBC: 790
test2.32Refresh&Analyze32C4: 786C3: 799C2: 794C1: 780

MH-C9000 CYCLE PROGRAM is "C>D>C":
starting from discharged state 1.18V (t = 00:00):

originally:
2h charge +2h pause +[4h dis] +1h pause
+2h charge +2h pause +[4h dis] +1h pause
+2h charge +2h pause +[4h dis] +1h pause
+2h charge + topoff&trickle
           
modified for continuous testing:
2h charge +2h pause +[4h dis] +1h pause
+2h charge +2h pause +[4h dis] +1h pause
+2h charge +2h pause +[4h dis] + INTERVENTION!

So the INTERVENTION takes place after 26hrs, sometime between (t = 26:0126:59):
take cells out and cool down in equalizer for few hours, not 1hour!
Then reinsert cells in permutated arrangement and start
CYCLE PROGRAM from this discharged equalized state 1.18V


For example, if you start the run on
Wed 06:00a.m.,
you should set the alarm clock for
Thu 08:00a.m.,
have removed the cells by
Thu 08:59a.m.,
and let them rest in the equalizer until say
Thu 11:59a.m.,
and then again started the next run (or "Cycle") on
Thu 12:00 noon, etc.

So the modified "Cycle" takes 30hrs.

comments on the above continued tests:
test2.5: C9000 again kinda does it. says that cell#2 has the highest and cell#4 the lowest capacity, with the order being cell#2 > #3 ≥ #1 > #4. as planned, let's let the cells rest in the C9000-cradle for 24+ hrs and then do another R&A, see next test.
test2.6: in this test i have permutated the cells in the cradle. capacity order is now cell#3 > #1 > #2 > #4.  this confirms that cell#4 has the lowest capacity but the rest is clearly inconsistent, if the C9000 were to measure mAh's super accurately. If there is variance or tolerance or 'play' in the mAh-readings, then the inconsistencies could be explained by them. well, as planned, let's let the cells rest in the cradle for 2-3 days from now on and then do the final test, the Disch2. at this point, and given all the other C9000 data in this post, we can tend to state that the C9000 is rather ACCURATE but not VERY ACCURATE. anyway, let's wait for the results of test2.7!
test2.7: TBD

In the meantime lemme keep the EBC-A busy with other discharges. I've got 6 cells of 14500's  hehe..
« Last Edit: April 02, 2014, 07:21:55 PM by dinoboy »
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dinoboy

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Re: Chinese battery capacity tester and batteries
« Reply #11 on: February 04, 2014, 09:16:43 AM »
test3.x-series: This post is about discharge tests with my 14500's.



Discharge Characteristics (by rate of discharge)
their temp for the graphs = 20C = our temp
Rated capacity at 20C = Min. 800mAh, that's our "C", not 840!
Minimum capacity at 25C = 800mAh, again that's our "C"!
Typical capacity at 25C = 840mAh

our horizontal cut = 2.80V, not their 2.50V
4569 pixels (black) = 1000mAh
3897 pixels (blue, 0.2C = 160mA ) = 854mAh
3865 pixels (red, 0.5C = 400mA ) = 847mAh
3831 pixels (green, 1C = 800mA ) = 839mAh
3697 pixels (violet, 2C = 1600mA) = 810mAh

Parameters, tentative:
  • starting voltage: fully charged, 4.200V+ offline
  • program: "DCHG 00 NOR 100W", i.e. Discharge Test
  • discharge rate: "00.10A", i.e -100mA
  • target voltage: "03.00V", i.e. 3.00V

my historic reference values from genuine Imax B6, with the same parameters (3.00V cut-off voltage and -100mA discharge rate):
protected TF14500 flames, cell#1: 759mAh (no repeated tests done for any of the cells!)
protected TF14500 flames, cell#2: 830mAh
protected TF14500 flames, cell#3: 744mAh
protected TF14500 flames, cell#4: 559mAh
protected TF14500 flames, cell#5: 786mAh
protected ZL854 (based on UR14500P cell): n/a (used condition)
unprotected Sanyo UR14500P, cell#1: n/a (new condition)
unprotected Sanyo UR14500P, cell#2: n/a (new condition)

some reference data measured found on the google:
UR14500P cell at -2000mA/3.00V discharge:
780mAh   2.655Wh : http://www.dampfakkus.de/akkutest.php?id=159
768mAh   2.626Wh : http://www.dampfakkus.de/akkutest.php?id=242
750mAh   2.530Wh : http://www.dampfakkus.de/akkutest.php?id=208
730mAh   2.488Wh : http://www.dampfakkus.de/akkutest.php?id=20

UR14500P cell at -1000mA/2.80V discharge:
808mAh  2.929Wh : KeepPower (2012)
803mAh  2.909Wh : KeepPower (2014)
803mAh  2.912Wh : Intl-Outdoor
802mAh  2.901Wh : EnerPower


my EBC-A results (repeated tests are not necessary as you know from test1.x-series results!):
test3.xwhat stuffDISCH parametersmAh at 2,80Vfinal resultmini notes (if any)
test3.1TF14500 flames cell#1-100mA/3.00VN/A785mAh 2901mWh> 759mAh
test3.7TF14500 flames cell#2-100mA/3.00VN/A843mAh 3127mWh> 830mAh
test3.8TF14500 flames cell#3-100mA/3.00VN/A763mAh 2829mWh> 744mAh
test3.9TF14500 flames cell#4-100mA/3.00VN/A530mAh 1958mWhneeds repetition
test3.10TF14500 flames cell#5-100mA/3.00VN/A813mAh 3024mWh> 786mAh
test3.12test3.1 repeated-100mA/3.00VN/A776mAh 2823mWhneeds repetition
test3.18test3.1 repeated again-100mA/3.00VN/A788mAh 2918mWhbeautiful!, > 759mAh
test3.14test3.7 repeated-100mA/3.00VN/A851mAh 3158mWhquite beautiful!, > 830mAh
test3.15test3.8 repeated-100mA/3.00VN/A762mAh 2831mWhbeautiful!, > 744mAh
test3.11test3.9 repeated-100mA/3.00VN/A535mAh 2036mWh< 559mAh
test3.13test3.9 repeated again-100mA/3.00VN/A533mAh 2029mWhbeautiful!, < 559mAh
test3.16test3.10 repeated-100mA/3.00VN/A811mAh 3018mWhbeautiful!, > 786mAh
test3.2ZL14500-100mA/2.80V870mAh 3304mWh
test3.3ZL14500-200mA/2.80V831mAh 3145mWh
test3.4ZL14500-500mA/2.80V794mAh 2947mWh
test3.5ZL14500-160mA/2.80V837mAh 3156mWh
test3.6ZL14500-400mA/2.80V774mAh 2730mWhbad run
test3.19test3.4  repeated-500mA/2.80V791mAh 2931mWh
test3.17test3.6  repeated-400mA/2.80V780mAh 2910mWh:-?
test3.20UR14500P cell#1 at 25C-400mA/2.50V818mAh819mAh 3081mWh
test3.21UR14500P cell#2 at 24C-400mA/2.50V817mAh818mAh 3079mWh
test3.22UR14500P cell#1 at 23C-160mA/2.50V863mAh864mAh 3303mWh
test3.23UR14500P cell#2 at 22C-160mA/2.50V860mAh861mAh 3287mWh
test3.24UR14500P cell#1 at 22C-800mA/2.50V816mAh819mAh 3010mWh
test3.25UR14500P cell#2 at 22C-800mA/2.50V814mAh816mAh 2998mWh
test3.26UR14500P cell#1 at 23C-500mA/2.50V828mAh829mAh 3109mWh
test3.27UR14500P cell#2 at 23C-500mA/2.50V828mAh829mAh 3104mWh> -400mA discharge
test3.28UR14500P cell#1 at 23C-1000mA/2.50V812mAh815mAh 2979mWh
test3.29UR14500P cell#2 at 23C-1000mA/2.50V813mAh816mAh 2983mWh
test3.30UR14500P cell#1 at 22C-1600mA/2.50V783mAh790mAh 2790mWh
test3.31UR14500P cell#2 at 22C-1600mA/2.50V787mAh794mAh 2805mWh
test3.32UR14500P cell#1 at 22C-2000mA/2.50V773mAh779mAh 2726mWh
test3.33UR14500P cell#2 at 22C-2000mA/2.50V773mAh780mAh 2725mWh
test3.34test3.20 repeated at 23C-400mA/2.50V808mAh809mAh 3052mWh
test3.35test3.21 repeated at 23C-400mA/2.50V809mAh810mAh 3052mWh
test3.36test3.26 repeated-500mA/2.50VxxxmAhxxxmAh xxxxmWh
test3.37test3.27 repeated-500mA/2.50VxxxmAhxxxmAh xxxxmWh
test3.38test3.30 repeated at 25C-1600mA/2.50VxxxmAhxxxmAh xxxxmWh
test3.39test3.31 repeated at 25C-1600mA/2.50VxxxmAhxxxmAh xxxxmWh


comments on the above tests:
test3.1: wowowo, something's fishy here. The mathematical difference of (785-759=) 26mAh is not very much tbh but in reality it is higher than that because of the cell degradation.  the cell is 2yrs old, yet reads higher than Imax B6 (785 vs. 759). i cannot fully comment on this surprising result, it's too early for a statement. since cell degradation, capacity loss due to aging should be reflected in the result, clearly, either Imax B6 gave an inaccurate result back then or EBC-A's reading is inaccurate. Either or! hopefully, during the course of the test3.x-series we'll find out which one's the truth!
test3.2: before we proceed with my old TF14500's let's do the Zebralight first and compare it with a more professional reference, HKJ's tests of EnerPower UR14500P and Intl-outdoor UR14500P, all right? HKJ tested 5 discharge rates with cutoff voltage 2.80V, let's begin with the lowest rate, -100mA. If the result is promising, i shall test the other 4 discharge rates as well. Note that my cell sample is 1yr old and that my test setup has higher electrical resistance than HKJ's professional test setup. Therefore at higher discharge rates, i do expect notable deviations from HKJ's measurements. (...) The result is much higher than HKJ and also higher than the "typical" nominal voltage (870 vs. 807 vs. 840). At the moment i am satisfied with the result. Why? If you check Panasonics PDF datasheet, it says "min. 800mAh, typ. 840mAh", so nominal capacity is 840mAh (same as nominal capacity of Eneloop AA is 2000mAh and not 1900mAh). this number also means that under perfect conditions (new, unabused cell, nice room temperature, low discharge rate) the capacity will be a bit higher, not lower than that! That's why Eneloop AA tests over 2000mAh, see danaco.net and other users' tables.  With higher discharge rates and colder room temperature, the capacity decreases. now check the graph in the Panasonics datasheet in zoomed-in detail: you'll see that the blue line is at ~54% between 800900mAh (2.5V intersection), i.e. ~854mAh. mind you, this is the line for -0.2A, not -0.1A discharge rate. This means that for lower discharge rates, the capacity must be higher and since 870 > 854, everything looks correct with my EBC result. I'll redo the discharge runs at -0.2A, -0.5A, -1.0A and -2.0A, as shown in the PDF (and as did HKJ) and we'll take the 2.8V intersection into account. With the 870mAh at my 0.1A-run, i would not wonder if i get near the 854mAh-mark with my 0.2A-run. Note that HKJ measured the same 807mAh-value for both 0.1, 0.2 and 0.5 amps discharge runs, which is physically impossible. The PDF shows clearly that the capacity is reduced between the 0.2 and the 0.5 amps discharge runs! Not by much, but you're getting my point, don't you? all right, nuff said. let's do the -0.2A discharge test and see how close we get to the 854mAh-mark!
test3.3: that's a bit lower than i had personally expected (831 vs. 854), especially after the previous test had resulted in such a nice high number. let's continue with the tests, first. if the following test results better match my expectations, then i would repeat this test run. what could i improve? well, the Zebralight cell does not have a protruding (+)plus pole and making good contact with the anode of the diy battery holder is a challenge. i could try to improve the electrical connection there without increasing the electrical Ohms resistance. it's a challenge!
test3.4: woh, that's too low compared to the PDF. let's try again lower currents. instead of 0.2A and 0.5A, we're gonna test 0.2C and 0.5C, as shown exactly in the PDF.
(...)
test3.8: clearly higher than Imax B6 reading (763 vs. 744). i don't know what to think of it. feels strange.
test3.9: sounds plausible to me, it's always been a poor cell. after 2yrs of casual use and aging it's become poorer (530 vs. 559).
« Last Edit: March 31, 2014, 07:38:01 AM by dinoboy »
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dinoboy

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Re: Chinese battery capacity tester and batteries
« Reply #12 on: February 07, 2014, 04:45:33 AM »
apart from the 1.x-series, all other above test series are still pending and not completed. but out of curiosity i am beginning a new series already. keep in mind that my posts are NOT about testing the cells. my aim is to find out a definite answer to the question if EBC-A is a very accurate, reliable, consistent battery analyzer. to this purpose, i need to discharge a bunch of cell models and compare my results with the existing literature. and the existing literature is Panasonic PDF-datasheets, battery reviews by test experts, and my parallel tests with reference machines such as Imax B6 and Maha C9000.

test4.x-series: This post is about discharge tests with my protected/unprotected NCR18650A's

Same cell inside, I own 4 different retail "types":



my EBC-A results:

test4.xwhat stuffDISCH parametersmAh at 3,00Vfinal resultmini notes (if any)
test4.1ET3100 red label-2000mA/2.80V2242mAh2658mAh 8750mWhpoor connection?
test4.2Protected NCR18650A cell#1-2000mA/2.80V2601mAh2816mAh 9508mWh
test4.3Protected NCR18650A cell#2-2000mA/2.80V2645mAh2807mAh 9597mWh
test4.4Unprotected NCR18650A cell#1-2000mA/2.80V2697mAh2835mAh 9855mWhperfect score!
test4.5Unprotected NCR18650A cell#2-2000mA/2.80V2628mAh2786mAh 9527mWh
test4.6Unprotected NCR18650A cell#3-2000mA/2.80V2665mAh2803mAh 9664mWh
test4.7Unprotected NCR18650A cell#4-2000mA/2.80V2660mAh2808mAh 9640mWh
test4.8test4.1 repeated-2000mA/2.80V2515mAh2740mAh 9209mWhmuch better!
test4.9test4.2 repeated-2000mA/2.80V2664mAh2831mAh 9665mWhbetter result!
test4.10test4.3 repeated-2000mA/2.80V2650mAh2812mAh 9637mWhnegligibly higher
test4.11test4.4 repeated-2000mA/2.80V2678mAh2825mAh 9788mWhbit lower
test4.12test4.5 repeated-2000mA/2.80V2669mAh2812mAh 9757mWhclearly higher
test4.13test4.6 repeated-2000mA/2.80V2704mAh2825mAh 9865mWhhigher
test4.14test4.7 repeated-2000mA/2.80V2682mAh2821mAh 9805mWhhigher
test4.15test4.1 repeated again-2000mA/2.80V2559mAh2759mAh 9353mWhhigher
test4.16test4.2 repeated again-2000mA/2.80V2678mAh2846mAh 9754mWha bit higher
test4.17test4.3 repeated again-2000mA/2.80V2627mAh2803mAh 9558mWhcontact resistance?
test4.18test4.4 repeated again-2000mA/2.80V2664mAh2813mAh 9761mWhagain lower
test4.19test4.5 repeated again-2000mA/2.80V2688mAh2815mAh 9809mWha bit higher
test4.20test4.6 repeated again-2000mA/2.80V2683mAh2813mAh 9769mWha bit lower
test4.21test4.7 repeated again-2000mA/2.80V2678mAh2821mAh 9782mWha bit lower
test4.22Protected NCR18650A cell#1-590mA/2.80V2937mAh3001mAh 10.81Wh< typ. 3100mAh
test4.23Unprotected NCR18650A cell#2-590mA/2.50V2966mAh@2,80V3010mAh 10.85Wh< typ. 3100mAh
test4.24Unprotected NCR18650A cell#1-590mA/2.50V2986mAh@2,80V3030mAh 10.92Wh< typ. 3100mAh
test4.25Protected NCR18650A cell#2-200mA/2.80V3148mAh3189mAh 11.67Wh> typ. 3100mAh
test4.26test4.24 repeated with 25C-590mA/2.50V3026mAh@2,80V3063mAh 11.00Wh< typ. 3100mAh
test4.27Protected NCR18650A cell#2-590mA/2.80V2876mAh2933mAh 10.55Wh< typ. 3100mAh
test4.28Protected NCR18650A cell#1 with 25C-590mA/2.50V3064mAh@2,80V3090mAh 11.16Wh< typ. 3100mAh
test4.29Protected NCR18650A cell#2 with 25C-590mA/2.50V3053mAh@2,80V3078mAh 11.13Wh< typ. 3100mAh
test4.30Protected NCR18650A cell#1 with 25C-2950mA/2.50V2936mAh@2,80V3028mAh 10.18Wh> min. 2950mAh
test4.31Protected NCR18650A cell#2 with 25C-2950mA/2.50V2894mAh@2,80V2993mAh 10.05Wh> min. 2950mAh
test4.32Unprotected NCR18650A cell#1 with 30C-2950mA/2.50V2962mAh@2,80V3032mAh 10.41Wh> min. 2950mAh
test4.33Unprotected NCR18650A cell#2 with 30C-2950mA/2.50V2950mAh@2,80V3023mAh 10.37Wh> min. 2950mAh
test4.34Unprotected NCR18650A cell#3-2950mA/2.50V2824mAh@2,80V2932mAh 9989mWh< min. 2950mAh
test4.35Unprotected NCR18650A cell#4-2950mA/2.50V2820mAh@2,80V2937mAh 9960mWh< min. 2950mAh
test4.36Unprotected NCR18650A cell#1-1000mA/2.50V2916mAh@2,80V2968mAh 10.58Wh> min. 2950mAh
test4.37Unprotected NCR18650A cell#2-1000mA/2.50V2913mAh@2,80V2964mAh 10.60Wh> min. 2950mAh
test4.38Unprotected NCR18650A cell#3-1000mA/2.50V2909mAh@2,80V2960mAh 10.57Wh> min. 2950mAh
test4.39Unprotected NCR18650A cell#4-1000mA/2.50V2915mAh@2,80V2969mAh 10.55Wh> min. 2950mAh
test4.40Protected NCR18650A cell#1-1000mA/2.50V2949mAh@2,80V3003mAh 10.65Wh> min. 2950mAh
test4.41Protected NCR18650A cell#2-1000mA/2.50V2903mAh@2,80V2955mAh 10.49Wh> min. 2950mAh
test4.42test4.36 repeated-1000mA/2.50V2915mAh@2,80V2966mAh 10.59Wh> min. 2950mAh
test4.43test4.37 repeated-1000mA/2.50V2888mAh@2,80V2941mAh 10.50Wh< min. 2950mAh
test4.44test4.38 repeated-1000mA/2.50V2881mAh@2,80V2933mAh 10.46Wh< min. 2950mAh
test4.45test4.39 repeated-1000mA/2.50V2908mAh@2,80V2961mAh 10.55Wh> min. 2950mAh
test4.46test4.40 repeated-1000mA/2.50V2946mAh@2,80V3002mAh 10.63Wh> min. 2950mAh
test4.47test4.41 repeated-1000mA/2.50V2907mAh@2,80V2958mAh 10.50Wh> min. 2950mAh
test4.48test4.37 repeated again-1000mA/2.50V2893mAh@2,80V2944mAh 10.51Wh< min. 2950mAh
test4.49test4.38 repeated again-1000mA/2.50V2889mAh@2,80V2940mAh 10.48Wh< min. 2950mAh
test4.50New unprotected NCR18650A-1000mA/2.50V3019mAh@2,80V3079mAh 11.00Wh> min. 2950mAh
test4.51test4.50 repeated-1000mA/2.50V2993mAh@2,80V3052mAh 10.94Wh> min. 2950mAh
test4.52New unprotected NCR18650A-590mA/2.50V3040mAh@2,80V3091mAh 11.19Wh< typ. 3100mAh
test4.53test4.52 repeated with 30C-590mA/2.50V3138mAh@2,80V3170mAh 11.50Wh> typ. 3100mAh
test4.54test4.52 repeated with 25C+-590mA/2.50V3088mAh@2,80V3130mAh 11.34Wh> typ. 3100mAh
test4.55test4.52 repeated with 25C-590mA/2.50V3052mAh@2,80V3100mAh 11.23Wh= typ. 3100mAh




my comments to EBC-A results:
test4.22: the typical capacity at 25C, -590mA discharge rate (=0.2C with C=2950) and 2.50V cutoff is according to the datasheet PDF officially ~3100mAh, and the manufacturer guarantees that in case of a poor production lot you'd still get min. 2950mAh under these 3 conditions. and this certainly has to refer to brand-new factory fresh cells! Guess what, my cell is 1) 14 months aged/old, 2) used/consumed, 3) room temperature was 21.5C, and 4) i had to use 2.80V cutoff because of the Protected cell. So no wonder that with -0.59A discharge rate i am getting only 3001mAh. Clearly, i should repeat this kind of test in hot summer with brand-new purchased Unprotected cells! I do have unprotected cells, so let's see what the capacity difference between 2.502.80V cutoff is. EDIT: the capacity difference is 44mAh. This means that we should add ~44mAh to get a more comparable result: 3001+44 = 3045mAh. This is still 55mAh short of the spec.  I am sure that i could compensate this little difference with a warmer room temperature and a brand-new cell! By the way, the webpage states 3070mAh as typical capacity, not mentioning which parameters were used for the discharge.
test4.23: nice result. below 3100 spec as expected. kinda silly to do serious testings with 14months old cells, huh? lol
test4.24: nice result. below 3100 spec as expected. kinda silly to do serious testings with 14months old cells, huh? lol

Annie are you ok - Are you ok Annie?  (kreisl greetz xtar ;=)
« Last Edit: March 31, 2014, 07:54:24 AM by dinoboy »
*FMI* i have 3 shipments pending (= 2*UX +1*HKE)

dinoboy

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Re: Chinese battery capacity tester and batteries
« Reply #13 on: February 13, 2014, 02:37:20 AM »
We're not done yet with the above test4.x-series. I was just wondering how my 4pcs of NRC18650B purchased in July are doing. They weren't in use much but are not too new anymore either. They must have left the Japanese factory at least 7 months ago! Cells age and lose max capacity. So before finishing up the above test series let's do already a quick check of their condition and health so that we know what to expect in the course of this test series. So first we'll start with conditioning the cells at 2 amps.

test5.x-series: This post is about discharge tests with my protected NCR18650B's



In contrast to NCR18650A specs, the specs for NCR18650B are clear. Both the webpages (global, europe) and the PDF state the same:
at 25C, min/typ 3250/3350mAh (i.e. C=3250), and 0.2C discharge rate is -650mA, 2.50V cutoff.
at 20C, min 3200mAh (i.e. C=3200), and 0.2C discharge rate is -640mA, 2.50V cutoff.

The PDF graph gives us typ mAh discharge data at 25C and different discharge rates based on C=3250. My cells are protected, so we need the typical mAh values at 2.80V cutoff:
Discharge Characteristics (by rate of discharge)
their temp = 25C (my room is colder than that unless !)
Rated capacity at 25C = Min. 3250mAh, that's our "C", not 3350 nor 3400!

for our horizontal cut = 2.80V, not their 2.50V:
4471 pixels (grey) = 4000mAh
3636 pixels (green, 0.2C = 650mA ) = 3253mAh
3524 pixels (blue, 0.5C = 1625mA ) = 3153mAh
3510 pixels (red, 1C = 3250mA ) = 3140mAh
3309 pixels (black, 2C = 6500mA) = 2960mAh

for their horizontal cut = 2.50V at 25C:
4471 pixels (grey) = 4000mAh
3699 pixels (green, 0.2C = 650mA ) = 3309mAh, i.e. < typ. 3350mAh!
3627 pixels (blue, 0.5C = 1625mA ) = 3245mAh
3667 pixels (red, 1C = 3250mA ) = 3280mAh
3679 pixels (black, 2C = 6500mA) = 3291mAh

These numbers are interesting. They state that at 25C you do get at least 3245mAh out of the cell, no matter the discharge rate 0.2C, 0.5C, 1C or 2C.


For this popular cell model by Panasonic, quite a lot of reference data is found on the google:

NCR18650B cell at -2000mA/3.00V discharge:
3104mAh   10.821Wh : http://www.dampfakkus.de/akkutest.php?id=141
2931mAh   10.103Wh : http://www.dampfakkus.de/akkutest.php?id=495
2883mAh     9.943Wh : http://www.dampfakkus.de/akkutest.php?id=479

NCR18650B cell at -2000mA/2.80V discharge:
3180mAh 11.061Wh : EnerPower+
3171mAh 10.845Wh : Sibeile
3151mAh 10.960Wh : Cytac
3150mAh 10.989Wh : KeepPower
3148mAh 10.890Wh : Efest (black)
3141mAh 10.899Wh : BattEnergy
3132mAh 10.826Wh : Eagletac
3128mAh 11.014Wh : Panasonic, unprotected
3116mAh 10.856Wh : Intl-Outdoor
3104mAh 10.722Wh : Xtar
3103mAh 10.761Wh : Panasonic, protected
3093mAh 10.696Wh : Efest (white)
3034mAh 10.609Wh : AmpMax

I own 1 model:

my EBC-A results:
test5.xwhat stuffDISCH parametersmAh at 3,00Vfinal resultmini notes (if any)
test5.1Generic protected NCR18650B cell#1-2000mA/2.80V2936mAh3107mAh 10.68Whneeds conditioning
test5.2Generic protected NCR18650B cell#2-2000mA/2.80V2962mAh3159mAh 10.75Wh
test5.3Generic protected NCR18650B cell#3-2000mA/2.80V2982mAh3161mAh 10.86Wh
test5.4Generic protected NCR18650B cell#4-2000mA/2.80V2966mAh3168mAh 10.84Wh
test5.5test5.1 repeated-2000mA/2.80V2882mAh3085mAh 10.52Whpoorer
test5.5test5.2 repeated-2000mA/2.80V2906mAh3093mAh 10.64Whlower
test5.7test5.3 repeated-2000mA/2.80V2976mAh3166mAh 10.81Wh
test5.8test5.4 repeated-2000mA/2.80V2877mAh3084mAh xxxxWhwronged
test5.9test5.1 repeated again-2000mA/2.80V2923mAh3096mAh 10.65Whmiddle
test5.10test5.2 repeated again-2000mA/2.80V2931mAh3112mAh 10.69Whmiddle
test5.11test5.3 repeated again-2000mA/2.80V2919mAh3102mAh 10.65Whlower wtf
test5.12test5.4 repeated again-2000mA/2.80V2927mAh3110mAh 10.65Whmiddle
test5.13Generic protected NCR18650B cell#1-650mA/2.50V3277mAh@2,80V3329mAh 11.95Wh< typ. 3350mAh
test5.14Generic protected NCR18650B cell#2-650mA/2.50V3281mAh@2,80V3333mAh 11.97Wh< typ. 3350mAh
test5.15Generic protected NCR18650B cell#3-650mA/2.50V3275mAh@2,80V3327mAh 11.94Wh< typ. 3350mAh
test5.16Generic protected NCR18650B cell#4-650mA/2.50V3282mAh@2,80V3333mAh 11.98Wh< typ. 3350mAh
test5.17test5.13 repeated with 25C-650mA/2.50V3338mAh@2,80V3376mAh 12.15Wh> typ. 3350mAh
test5.18test5.14 repeated with 25C-650mA/2.50V3350mAh@2,80V3385mAh 12.21Wh> typ. 3350mAh
test5.19test5.15 repeated-650mA/2.50V3265mAh@2,80V3318mAh 11.91Wh< typ. 3350mAh
test5.20test5.16 repeated-650mA/2.50V3279mAh@2,80V3328mAh 11.97Wh< typ. 3350mAh
test5.21Generic protected NCR18650B cell#1 with 25C-1620mA/2.50V3251mAh@2,80V3322mAh 11.55Wh< typ. 3350mAh
test5.22Generic protected NCR18650B cell#2-1620mA/2.50V3142mAh@2,80V3237mAh 11.19Wh< typ. 3350mAh
test5.23Generic protected NCR18650B cell#3 with 25C-1620mA/2.50V3218mAh@2,80V3289mAh 11.47Wh< typ. 3350mAh
test5.24Generic protected NCR18650B cell#4-1620mA/2.50V3148mAh@2,80V3236mAh 11.25Wh< typ. 3350mAh
test5.25Generic protected NCR18650B cell#1 with 25C-3250mA/2.50V3142mAh@2,80V3291mAh 10.89Wh> min. 3250mAh
test5.26Generic protected NCR18650B cell#2 with 25C-3250mA/2.50V3139mAh@2,80V3286mAh 10.88Wh> min. 3250mAh
test5.27Generic protected NCR18650B cell#3 with 25C-3250mA/2.50V3137mAh@2,80V3277mAh 10.90Wh> min. 3250mAh
test5.28Generic protected NCR18650B cell#4 with 25C-3250mA/2.50V3158mAh@2,80V3288mAh 10.94Wh> min. 3250mAh
« Last Edit: March 31, 2014, 08:06:45 AM by dinoboy »
*FMI* i have 3 shipments pending (= 2*UX +1*HKE)

dinoboy

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Re: Chinese battery capacity tester and batteries
« Reply #14 on: March 03, 2014, 11:03:20 AM »
reference values from Panasonic, HKJ and dampfakkus:

The specs for NCR18650A are given in the 2 PDF-datasheets by Panasonic (global, europe) and they state the same:
at 25C, min/typ 2950/3100mAh (i.e. C=2950), and 0.2C discharge rate is -590mA, 2.50V cutoff.
at 20C, no min/typ data is given

The identical PDF graphs give us typ mAh discharge data at 25C and different discharge rates based on C=2950. My cells are both protected and unprotected, so we should find the typical mAh values at 2.80V cutoff handy:
Quote
Discharge Characteristics (by rate of discharge)
their temp = 25C (my room is colder than that unless !)
Rated capacity at 25C = Min. 2950mAh, that's our "C", not 3100!

for our horizontal cut = 2.80V, not their 2.50V, at 25C:
8079 pixels (black) = 3000mAh & 2164 px = 1.0V (0.3V = 649px)
8094 pixels (turquoise, 0.2C = 590mA) = 3005mAh
7782 pixels (grey, 1C = 2950mA) = 2890mAh
8032 pixels (blue, 2C = 5900mA) = 2982mAh

8078 pixels (black) = 3000mAh & 2169px = 1.0V (0.3V = 651px)
8086 pixels (red, 0.2C = 590mA) = 3003mAh
7775 pixels (green, 1C = 2950mA) = 2887mAh
8017 pixels (blue, 2C = 5900mA) = 2977mAh

for their horizontal cut = 2.50V at 25C:
8079 pixels (black) = 3000mAh & 2164 px = 1.0V
8252 pixels (turquoise, 0.2C = 590mA) = 3064mAh, i.e. < typ. 3100mAh!
8118 pixels (grey, 1C = 2950mA) = 3014mAh
8559 pixels (blue, 2C = 5900mA) = 3178mAh

8078 pixels (black) = 3000mAh & 2169px = 1.0V
8253 pixels (red, 0.2C = 590mA) = 3065mAh, i.e. < typ. 3100mAh!
8117 pixels (green, 1C = 2950mA) = 3014mAh
8549 pixels (blue, 2C = 5900mA) = 3175mAh

These numbers are interesting. They state that at 25C you do get at least 3014mAh out of the cell, no matter the discharge rate 0.2C, 1C or 2C.


NCR18650A    -1000mA/3.00V    -2000mA/3.00V    -3000mA/3.00V
NitcoreN/A2658mAh   9.163Wh2436mAh 8251mWh
Enerpower+N/A2648mAh   9.041Wh2267mAh 7538mWh
BICN/A2629mAh   8.998Wh2406mAh 8066mWh
PanasonicN/A2626mAh   9.095Wh2531mAh 8605mWh

NCR18650A    -1000mA/2.80V    -2000mA/2.80V    -3000mA/2.80V
Orbtronic2923mAh 10.435Wh2872mAh 10.007Wh2849mAh 9705mWh
Sibeile2930mAh 10.512Wh2866mAh 10.081Wh2838mAh 9802mWh
AmpMax2928mAh 10.454Wh2867mAh 9.988Wh2845mAh 9690mWh
BattEnergy2906mAh 10.347Wh2857mAh 9.911Wh2842mAh 9626mWh
RediLast2910mAh 10.384Wh2854mAh 9.928Wh2825mAh 9604mWh
KeepPower2904mAh 10.357Wh2851mAh 9.917Wh2826mAh 9608mWh
4Greer2884mAh 10.241Wh2840mAh 9.769Wh2821mAh 9420mWh
Intl-Outdoor blue2907mAh 10.272Wh2840mAh 9.687Wh564mAh 2009mWh
Xtar2869mAh 10.184Wh2826mAh 9.725Wh2774mAh 9267mWh
Callies Kustoms2877mAh 10.246Wh2821mAh 9.779Wh2798mAh 9468mWh
Intl-Outdoor black2869mAh 10.241Wh2813mAh 9.796Wh2790mAh 9495mWh
Efest2891mAh 10.210Wh2807mAh 9.553Wh0mAh 0mWh
EnerPower+2866mAh 10.152Wh2807mAh 9.638Wh2780mAh 9265mWh
Eagletac black2865mAh 10.166Wh2807mAh 9.646Wh2763mAh 9213mWh
AW2833mAh 10.092Wh2781mAh 9.646Wh2746mAh 9295mWh
« Last Edit: March 03, 2014, 11:22:14 AM by dinoboy »
*FMI* i have 3 shipments pending (= 2*UX +1*HKE)