# Standardized PL6 testing for A123 cells and compiling data



## rwaudio (May 22, 2008)

Some data, capacity and IR for 151 cells. I tested another 60ish with a different method but these are all PL6
38A charge to 3.65v terminate C/20
38A discharge to 2.25v

My pair of PL6's are virtually identical, purchased at different times, but testing a pair of cells then letting them sit, swapping chargers and testing again has given ~0.05Ah maximum variation. I did this test a few times with the same results. If I let the cell sit overnight or for a few days I typically got within 0.02Ah.

Cell Capacity PL6	IR
17.43	0.8
17.57	0.6
17.60	0.7
17.66	0.7
17.66	0.7
17.70	0.7
17.72	0.7
17.73	0.7
17.76	0.7
17.76	0.8
17.78	0.7
17.82	0.7
17.83	0.7
17.84	0.7
17.86	0.7
17.89	0.7
17.91	0.6
17.92	0.8
17.92	0.7
17.95	0.8
17.99	0.7
18.00	0.7
18.06	0.65
18.08	0.7
18.11	0.7
18.13	0.7
18.15	0.7
18.25	0.6
18.26	0.7
18.27	0.7
18.28	0.6
18.31	0.6
18.33	0.65
18.33	0.7
18.33	0.7
18.34	0.7
18.34	0.7
18.35	0.7
18.36	0.6
18.37	0.7
18.39	0.7
18.40	0.7
18.40	0.7
18.41	0.7
18.41	0.7
18.44	0.7
18.44	0.7
18.47	0.65
18.49	0.8
18.50	0.7
18.50	0.8
18.51	0.7
18.51	0.7
18.51	0.7
18.52	0.6
18.52	0.7
18.52	0.7
18.54	0.8
18.55	0.7
18.55	0.7
18.55	0.7
18.55	0.7
18.56	0.6
18.56	0.65
18.56	0.7
18.56	0.7
18.57	0.7
18.59	0.7
18.59	0.7
18.59	0.7
18.59	0.7
18.60	0.65
18.61	0.7
18.61	0.7
18.62	0.6
18.62	0.6
18.62	0.65
18.62	0.7
18.62	0.8
18.63	0.7
18.64	0.7
18.65	0.7
18.65	0.7
18.67	0.7
18.69	0.6
18.69	0.6
18.69	0.7
18.69	0.7
18.70	0.6
18.70	0.7
18.71	0.75
18.72	0.7
18.73	0.7
18.73	0.7
18.74	0.7
18.75	0.75
18.77	0.6
18.77	0.7
18.77	0.7
18.78	0.8
18.79	0.65
18.79	0.7
18.80	0.7
18.80	0.7
18.81	0.7
18.81	0.7
18.83	0.8
18.84	0.7
18.84	0.8
18.85	0.7
18.87	0.8
18.88	0.6
18.88	0.65
18.88	0.7
18.90	0.8
18.91	0.7
18.92	0.65
18.92	0.7
18.92	0.7
18.93	0.7
18.93	0.8
18.94	0.7
18.97	0.7
18.98	0.7
19.00	0.6
19.00	0.6
19.01	0.7
19.02	0.7
19.03	0.7
19.05	0.7
19.12	0.7
19.12	0.7
19.14	0.6
19.15	0.7
19.16	0.6
19.16	0.7
19.16	0.7
19.17	0.7
19.18	0.6
19.19	0.6
19.19	0.7
19.20	0.7
19.21	0.7
19.21	0.7
19.25	0.6
19.26	0.6
19.30	0.6
19.31	0.7
19.39	0.7
19.47	0.6
19.52	0.7


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## adamj12b (May 4, 2009)

I like this idea alot as I plan to start testing these cells withing the next month. 

I have been planing to use the PL6 as well for its high power discharge. 

I plan to test my cells at at least 1C, but might even go to 2C as these are working range of batteries in an EV. 

What are you guys using for charge/ discharge cycles?

I was thinking out of the box, top the cells to 3.65V. Then a discharge cycle to either 2.0 or 2.25V measure capacity and another charge to 3.65 for storage while I build the packs. If the charge/discharge rate is 2C, then a cell should be able to be tested about ever hour. Do you think this is testing the cells too hard? The datasheet for these cells say only 10% capacity loss after 3000 cycles with 2.0v being the LVC if I remember correctly.

I plan to test all of my cells and then group them based on capacity and internal resistance, matching the parallel cells as close as I possibly can. 

Im thinking about ordering my PowerLab6 today, anybody know a better price then $197.95 for the kit with the output leads and serial adapter? 

-Adam


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## boekel (Nov 10, 2010)

adamj12b said:


> Im thinking about ordering my PowerLab6 today, anybody know a better price then $197.95 for the kit with the output leads and serial adapter?


I bought the PL8 because the 6 was out of stock for the 'non usa' store..

I just got this in the mail from Revo, maybe you can save some money (tough not for first time customers):

Now through March 31, 2012, receive 10% OFF normal retail price for any PowerLab 6 or PowerLab 6 Combo! Any orders you place between now and March 31 qualify. This offer is available only through the REVO USA webstore. To obtain this special limited-time pricing, enter coupon code *PR032112* in the coupon code field during checkout, then click "Apply". Code is unlimited in that you may use it as many times as you like during the offer period.  


[FONT=Arial, Arial Black]_Please note: The Revo store does not recognize promotional codes for first time buyers on the site. If you are a first time buyer who qualifies for the promotional code, please call REVO USA sales at (301) 798-2770 and we will assist you with the order and insure you receive the special 10% savings offer._[/FONT]


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## kerrymann (Feb 17, 2011)

adamj12b said:


> I like this idea alot as I plan to start testing these cells withing the next month.
> 
> I have been planing to use the PL6 as well for its high power discharge.
> 
> ...


 I am repeating my cells with rwaudio's settings (see above). It's only 2C which is well within the operating range of these cells. I only have eight now but I will be ordering 220 next week. 



rwaudio said:


> Some data, capacity and IR for 151 cells. I tested another 60ish with a different method but these are all PL6
> 38A charge to 3.65v terminate C/20
> 38A discharge to 2.25v
> 
> My pair of PL6's are virtually identical, purchased at different times, but testing a pair of cells then letting them sit, swapping chargers and testing again has given ~0.05Ah maximum variation. I did this test a few times with the same results. If I let the cell sit overnight or for a few days I typically got within 0.02Ah.


Thanks! I am plugging it into excel and I will post it here along with my limited data.


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## rwaudio (May 22, 2008)

Also just to clarify, mine were some of the earliest A123's available outside of A123RC.com they are the tabless cells.

I have 152 more cells that will be coming soon, some for me some for others.
I will probably be measuring them all. They are cells with 12.1mm tabs not the full length tabs. I will continue testing with my settings and see how these compare to tabless cells.


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## kerrymann (Feb 17, 2011)

Sorry I haven't done anything on this recently. I am dealing with motor adapter issues right now, but that is another thread.....

Actually the big issue I ran into is that after the 2nd cell was retested at 2C my PL6 stoped charging. It act likes it working with a setpoint at 38amps but shows 0 amps of current. I have called and emailed their tech support a couple times but haven't gotten a reply. If anyone else has run into this or a solution, please let me know.

I was thinking about ordering another PL6 to test my 250 cells so I might go ahead and do it now.

Kerry


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## rwaudio (May 22, 2008)

kerrymann said:


> Sorry I haven't done anything on this recently. I am dealing with motor adapter issues right now, but that is another thread.....
> 
> Actually the big issue I ran into is that after the 2nd cell was retested at 2C my PL6 stoped charging. It act likes it working with a setpoint at 38amps but shows 0 amps of current. I have called and emailed their tech support a couple times but haven't gotten a reply. If anyone else has run into this or a solution, please let me know.
> 
> ...


Once in awhile I get an error message, and it typically seems to be caused by a communication error to the PC, the last few cells I've tested I use the controls on the primary to initiate charging. The firmware has a few bugs, but both of mine typically work well.


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## Henkka (Jan 7, 2012)

This common database of test results sounds very good! We actually tried to do similar database with eCars-Now OS-community before with Thundersky cells but only managed to do few cold-temperature tests (see http://www.sahkoautot.fi/paja:batterytests , you can see our Open Source web-software doing all the logging and gathering a "common database" of test-results). But this database never got very far, only few tests were done - lack of time and too few people doing the actual tests... 

But now I have 10 x A123 cells too (for my Porche 944) and have so far tested 4 of them with 1C (20A). I have usually tested with 2 cycles to see if there is any significant rise in capacity. So far difference between first and second cycle has been very small. I could also test with 2C (as I have PL8) after I have completed my 1C & 2 cycles testing.

For my use, I need also data how much temperature affects capacity and how much these cells warm up when discharged. (As it gets rather cold here in Finland during wintertime, -25 C is quite normal. And I have not found actual data about any serious cold temperature "lab" testing available.)

So for that reason my recent test-setup (photos in http://www.flickr.com/photos/yty/sets/72157629380248814/) includes 20 mm styrofoam on both sides of the acrylic cell-clamping device to thermally isolate the cell from ambient air. For now I log temperatures with just 2 cheap multimeters but it's rather tedious job to combine PL8 logs with temperature logs. So for that reason I have thought of writing simple program just to control PL8 and to use Arduino with LM335 temp-sensors and read those as well. My friend has already done that with Labview and is going to control 5 PL8 units for some serious testing with Turnigy Nano-cells.

In what temperature you guys are testing the cells ? I would think that something like 20 C (68 F) could be a "standard" temperature?

My cells so far have all been under 17Ah, actually between 15.5 - 16.9 Ah. I need to test them all to see actual variation.

You can see the cells in http://www.flickr.com/photos/yty/sets/72157629495306153/

Henkka
-- 
http://randomev.wordpress.com - Random EV blog, Porche 944, CAN devices etc.


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## rwaudio (May 22, 2008)

Henkka said:


> This common database of test results sounds very good! We actually tried to do similar database with eCars-Now OS-community before with Thundersky cells but only managed to do few cold-temperature tests (see http://www.sahkoautot.fi/paja:batterytests , you can see our Open Source web-software doing all the logging and gathering a "common database" of test-results). But this database never got very far, only few tests were done - lack of time and too few people doing the actual tests...
> 
> But now I have 10 x A123 cells too (for my Porche 944) and have so far tested 4 of them with 1C (20A). I have usually tested with 2 cycles to see if there is any significant rise in capacity. So far difference between first and second cycle has been very small. I could also test with 2C (as I have PL8) after I have completed my 1C & 2 cycles testing.
> 
> ...


The cells are rated with a discharge to 2.0v so only discharging to 2.8v will explain the significant difference in measured capacity. It doesn't matter what you actually do in the car (I won't discharge below 2.5 or 2.75v) however to get a fairly accurate capacity I'm discharging to 2.25v


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## dladd (Jun 1, 2011)

here's my observations after using a PL6 to test cycle my 48 CALB cells (130ah). 

1. it was fairly common for the charger to fault for some reason at the bottom of the cycle. It would fully discharge, then have some kind of communication error and not begin the charge cycle. I'd just have to stop the program, and restart it as a single charge cycle instead of a full cycle to finish the cell. It just meant I needed to be quite watchful of the process, not just set it and forget it.

2. The IR readings are all over the place. even on the same cell, the IR would vary from .5-.9 depending on where it is in the charge cycle. I just decided on a consistent part of the charge curve (about 10 minutes into the charge cycle, still at a low SOC) to make the reading for comparisons sake.

3. I charged all the cells up to 3.60v, c/20 current shutoff. I DID NOT put the cells in parallel at any time. I then re-installed in my car, wired them up in series, and drove it. On the next charge cycle, my charger brought them up to an average of 3.50vpc and the voltages on the individual cells ranged from 3.40 to 3.53 volts. This is a much larger variance than I was expecting, I thought they would be much closer top balanced after individually charging them to 3.60v on the PL6. After seeing this variance, I did a little top balancing with a power supply to bring them all a bit closer.


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## Henkka (Jan 7, 2012)

rwaudio said:


> The cells are rated with a discharge to 2.0v so only discharging to 2.8v will explain the significant difference in measured capacity. It doesn't matter what you actually do in the car (I won't discharge below 2.5 or 2.75v) however to get a fairly accurate capacity I'm discharging to 2.25v


Yes, this definitely could be the reason. For comparison, I need to test with same parameters as you have been testing. So I'm going to do some tests with the same current (38A) and voltage between 3.65 - 2.25V.


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## marc02228 (Jan 15, 2011)

My 8 sample cells just arrived. They all have a voltage of 3.29V - 3.293V. 
I just wanted to start charging them. How can I create a custom (user) preset? 
Maybe I overread something in the manual, but i didn't find anything about it.
If I delete a preset and want to edit it, the charger says it can't edit an empty preset or so. 

I don't have the PC USB connector yet, because I didn't find it in germany anywhere...


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## kerrymann (Feb 17, 2011)

rwaudio said:


> Once in awhile I get an error message, and it typically seems to be caused by a communication error to the PC, the last few cells I've tested I use the controls on the primary to initiate charging. The firmware has a few bugs, but both of mine typically work well.


 I tried that but still nothing. I finally got a hold of tech support and after a 2 minute call he said it was a bad unit and they would replace it (I have to pay return shipping). Meanwhile I still have 256 cells to test.....

BTW, if you do need tech support help I recommend filling a case using their website:
To initiate a case directly :
1. Log on to your account at www.store.revolectrix.com
2. Click the "My Account" tab
3. Under Support, click "Contact Support"
4. On the case form, enter a subject which contains the product name, part number, or description
5. Type a message in the message field
6. The fields on the top right of the form are optional
7. Click Submit
Or calling directly (if you don't get voice mail) (301) 829-5533

In my 3 attempts to request support via email ([email protected]) they never got it or responded. 

Also FYI, if you buy direct from them if you do need a replacement the can ship one out as soon as your case is approved. If you buy from another source (like I did) they need to get the old one first.
　


rwaudio said:


> The cells are rated with a discharge to 2.0v so only discharging to 2.8v will explain the significant difference in measured capacity. It doesn't matter what you actually do in the car (I won't discharge below 2.5 or 2.75v) however to get a fairly accurate capacity I'm discharging to 2.25v


RW would you mind attaching your preset to this thread? We can all just use that and be confident in the test set-up.



marc02228 said:


> My 8 sample cells just arrived. They all have a voltage of 3.29V - 3.293V.
> I just wanted to start charging them. How can I create a custom (user) preset?
> Maybe I overread something in the manual, but i didn't find anything about it.
> If I delete a preset and want to edit it, the charger says it can't edit an empty preset or so.
> ...


 　
I have only done it with USB cable.  I have run custom presets without the USB cable and I am pretty sure you can program but I don't think it will report the capacity? The USB connection is what logs the data and where I record my capacities.


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## marc02228 (Jan 15, 2011)

kerrymann said:


> I have only done it with USB cable. I have run custom presets without the USB cable and I am pretty sure you can program but I don't think it will report the capacity? The USB connection is what logs the data and where I record my capacities.


Just got my FUIM3 and started to put cycles on the cells.
I setup a discharge current of 20Ah but the PL6 only discharges at 8.0Ah. Why does it do this? Is that the max. discharge current without regenerative discharging?
How do I tell the PL6 to measure the internal resistance? It just says.. 
Cell 1= -.- mΩ

Btw. my first cell was 19161 mAh but @ 8A & C/10 and the same voltage that you use..

Just to clarify, you use and post the discharge capacity not the charge capacity, right?


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## adamj12b (May 4, 2009)

marc02228 said:


> Just got my FUIM3 and started to put cycles on the cells.
> I setup a discharge current of 20Ah but the PL6 only discharges at 8.0Ah. Why does it do this? Is that the max. discharge current without regenerative discharging?
> How do I tell the PL6 to measure the internal resistance? It just says..
> Cell 1= -.- mΩ
> ...


I think you have the supply set to power supply an not battery. It has to be connected to a 12 or 24V battery to do regenerative discharge. 

IR will only be calculated during charge and can only be calculated on a cell with less then 75% charge. 

Yes. You post the Discharge capacity as this is what is actually available in the cell.

-Adam


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## kerrymann (Feb 17, 2011)

marc02228 said:


> Just got my FUIM3 and started to put cycles on the cells.
> I setup a discharge current of 20Ah but the PL6 only discharges at 8.0Ah. Why does it do this? Is that the max. discharge current without regenerative discharging?
> How do I tell the PL6 to measure the internal resistance? It just says..
> Cell 1= -.- mΩ
> ...


I think that you don't have the balance wires connected. In addition to the charge cables you need to connect pins 1 + 9 (the red and black ones) to the cell to get the highest current. These are also used to measure the resistance.

Yes, you want discharge capacity. (you only worry about charge capacity if it's for a TV show


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## rwaudio (May 22, 2008)

kerrymann said:


> RW would you mind attaching your preset to this thread? We can all just use that and be confident in the test set-up.


looks like I missed this.

Attached is the pre-set that I use.


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## marc02228 (Jan 15, 2011)

kerrymann said:


> I think that you don't have the balance wires connected. In addition to the charge cables you need to connect pins 1 + 9 (the red and black ones) to the cell to get the highest current. These are also used to measure the resistance.


Thx.. I Had to connect the balance wires. I connected 1 and 9 but when I look at RWAUDIO's blog I can see that he connected the black wire and the white one next to it. What's the correct configuration?
Now it is discharging @ 38A.

Edit:
I tested 2 Cells.. both had a Ir of 4.6mΩ. Could it be because I used 1 and 9 of the balancer cables?
Do your cells get slightly warm when charging or discharging @38A?


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## rwaudio (May 22, 2008)

marc02228 said:


> Thx.. I Had to connect the balance wires. I connected 1 and 9 but when I look at RWAUDIO's blog I can see that he connected the black wire and the white one next to it. What's the correct configuration?
> Now it is discharging @ 38A.
> 
> Edit:
> ...


There are two ways to correctly hook it up. However you need the matching software settings to the hardware configuration that you use. If you are using the PC interface go to the options tab and under start settings there is a pull down called "Node Wiring" this basically tells the charger what wires to use. It's in the manual but I believe FMA wiring uses 1 and 9 and XM/EH uses 1 and 2.

The important key to getting consistent Ir readings is to use alligator clips or similar to connect the balance wires to the cell tabs directly and not the current carrying blocks/connectors or whatever you are using to connect the charger to the cells. (Notice in the attached picture I keep the high current connections and balance wires as separated as possible)

My cells get warm to the touch but not hot when charging/discharging at 38A.


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## marc02228 (Jan 15, 2011)

rwaudio said:


> There are two ways to correctly hook it up. However you need the matching software settings to the hardware configuration that you use. If you are using the PC interface go to the options tab and under start settings there is a pull down called "Node Wiring" this basically tells the charger what wires to use. It's in the manual but I believe FMA wiring uses 1 and 9 and XM/EH uses 1 and 2.
> 
> The important key to getting consistent Ir readings is to use alligator clips or similar to connect the balance wires to the cell tabs directly and not the current carrying blocks/connectors or whatever you are using to connect the charger to the cells. (Notice in the attached picture I keep the high current connections and balance wires as separated as possible)
> 
> My cells get warm to the touch but not hot when charging/discharging at 38A.


Thanks for your explanation. My cells just get a little bit warm, not hot. So the Ri has to be ok, since I use your preset (38A discharge), now.
After I changed the connection of the balancer cables on the tabs, i get a Ri of 0.8mΩ except one cell which had 0.9mΩ

these are the Capacities of my sample cells...

#1	18563	0,9m
#2	18377	0,8m
#3	18243	0,8m
#4	18380	0,8m
#5	18093	0,8m
#6	18010	0,8m
#7	18660	0,8m
#8	18390	0,8m


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## kerrymann (Feb 17, 2011)

rwaudio said:


> The cells are rated with a discharge to 2.0v so only discharging to 2.8v will explain the significant difference in measured capacity. It doesn't matter what you actually do in the car (I won't discharge below 2.5 or 2.75v) however to get a fairly accurate capacity I'm discharging to 2.25v


Did you do any testing down to 2v? I am curious if how much (or in the case little) that changes the capacity reading?



marc02228 said:


> Thanks for your explanation. My cells just get a little bit warm, not hot. So the Ri has to be ok, since I use your preset (38A discharge), now.
> After I changed the connection of the balancer cables on the tabs, i get a Ri of 0.8mΩ except one cell which had 0.9mΩ
> 
> these are the Capacities of my sample cells...
> ...


I have added your cells into the excel list which if I can figure out how to attach a xlsx then I will share it. This is a first cut but will show you the average values and also graph out the distribution.

My new PL6 arrived today and is working but I have gotten two error 97s when the program was in the cool down stage. 4 down, 254 to go.....


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## kerrymann (Feb 17, 2011)

Had to zip it to attach it.


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## rwaudio (May 22, 2008)

kerrymann said:


> Did you do any testing down to 2v? I am curious if how much (or in the case little) that changes the capacity reading?


I did do some testing, the difference was between 200mah - 300mah between 2.25 and 2.0. The issue I had with 2.0 was it took much longer for the cell voltage to recover and when I was finishing with a charge cycle the charger would often time out because the voltage hadn't recovered above the min 2.55 for charging. Switching to 2.25 solved the problem and was extremely close in capacity.


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## marc02228 (Jan 15, 2011)

@Kerrymann
The Excel sheet looks nice. Good work. 

Some more details about my cells:
Tab: full
Condition: new
Importer: the same as yours

Yesterday I ordered another 400 cells. Paid by T/T, which saved me 650US$


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## kerrymann (Feb 17, 2011)

marc02228 said:


> @Kerrymann
> The Excel sheet looks nice. Good work.
> 
> Some more details about my cells:
> ...


Thanks! 400 cells? What are you going to do with all of them? What is T/T?


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## kerrymann (Feb 17, 2011)

Updated with more data and a tab at the end for testing that was not done using rwaudio's preset (thnanks BTW). It is interesting seeing the capacity difference at difference discharge rates. (if you want a cell to look good test it at 2 amps). The excel sheet should be ready for anyone to add data. There are instructions on the first sheet, if you have questions, bugs, enhancements, just ask. (I should probably add a revision history) 

My hope is that as people get data they will down load the latest file, add their numbers and repost it. If you want a buzzword, we'll call it "crowd testing" 

I am only getting through 5 cells a night so I think I will be buying another PL6 tomorrow....

Thanks in advance to all,


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## marc02228 (Jan 15, 2011)

kerrymann said:


> Thanks! 400 cells? What are you going to do with all of them? What is T/T?


I'm gonna build a car battery don't know yet, if 96s3p or 96s4p because I'm not sure what car I should take. 
The dictionary says to me, T/T = Bankwire transfer I don't know if it is the correct word. It's a simple way to transfer money.

Just got the mail, that my money arrived. So it only takes 2 days... not bad for a saving of 650US$

I guess, I need a 2nd PL6, too.


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## marc02228 (Jan 15, 2011)

My cells arrived. I measured the voltage of all 410 cells.
Most were 3,29V. 4 or 5 were down to 3,22V. 
Until now, all made in USA. 
So if anyone should buy from victpower, you should pay by T/T. Especially if you don't have a Paypal Account in US$. This saved me more than 500Euro ~650US$ and just took 2 days more.

On some cells there are marks on the tabs (all on the anode):

C
Romulus Anode
4K

or a green 6 written on some cells.

did anyone figure out, what these marks mean?
Somewhere I read about that Romulus anode in the forum...

I got 2 cells for free, or i miscounted...


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## jackbauer (Jan 12, 2008)

Just wondering if anyone had a problem getting regen discharge to work on the pl6? Just started using mine and it starts in regen till about 50ma then drops into normal discharge and maxes out about 7amps. I have balance wires setup etc but don't as yet have the pc interface.


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## rwaudio (May 22, 2008)

jackbauer said:


> Just wondering if anyone had a problem getting regen discharge to work on the pl6? Just started using mine and it starts in regen till about 50ma then drops into normal discharge and maxes out about 7amps. I have balance wires setup etc but don't as yet have the pc interface.


Make sure the PL6 is connected to a suitable battery that is not fully charged and can accept the current, and the charger is set to battery and not power supply.


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## boekel (Nov 10, 2010)

rwaudio said:


> Make sure the PL6 is connected to a suitable battery that is not fully charged and can accept the current, and the charger is set to battery and not power supply.


Maybe the 'maximum voltage' for the regen-battery is set to low? (or the battery is actually full)


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## marc02228 (Jan 15, 2011)

I just connected my 2nd PL6. I use the preset from rwaudio. After charge is completed, it starts discharging at 38A. After 2Ah or so of discharge, i get an error. 
"SVS System Reset". 
It is on primary. Did anyone have that error, too? It is on primary. The other charger says Safety code 82

What could be the problem?

A few seconds before the error is shown, the fan of the charger gets a little bit irregular.

edit: I get the same error, if I just use the charger alone, without the other.


----------



## kerrymann (Feb 17, 2011)

jackbauer said:


> Just wondering if anyone had a problem getting regen discharge to work on the pl6? Just started using mine and it starts in regen till about 50ma then drops into normal discharge and maxes out about 7amps. I have balance wires setup etc but don't as yet have the pc interface.


Did you go into the options and select the right power source? Are you using rwaudio's preset? The PL6 can discharge a 38amps with or without regen, it just turns it into waste heat. I'd say double check the setting for the power source, the preset, and the balance wires. Past that contact their CS.


----------



## kerrymann (Feb 17, 2011)

marc02228 said:


> I just connected my 2nd PL6. I use the preset from rwaudio. After charge is completed, it starts discharging at 38A. After 2Ah or so of discharge, i get an error.
> SVS System Reset. It is on primary. Did anyone have that error, too? It is on primary.
> 
> What could be the problem?
> ...


I had to give up on linking the PL6s. My problems were that I would get an error during the cool down phase and I noticed that if the primary reached it's setpoint then it would terminate both PL6s resulting in a lower capacity reading on the cell(s) on the slave PL6s. I had been contacting the CS about this but they have gone silent and I just gave up and are doing them manually which is annoying but not that big of a deal.


----------



## rwaudio (May 22, 2008)

marc02228 said:


> I just connected my 2nd PL6. I use the preset from rwaudio. After charge is completed, it starts discharging at 38A. After 2Ah or so of discharge, i get an error.
> "SVS System Reset".
> It is on primary. Did anyone have that error, too? It is on primary. The other charger says Safety code 82
> 
> ...


SVS System Reset usually means bad connection to the battery system running the chargers, make sure you have good solid connections.


----------



## marc02228 (Jan 15, 2011)

bevore I connected the 2nd charger it worked fine. Now it doesn't matter, if 1 or 2 chargers are connected. I get the error.
I'm using rwaudio's preset.

Here a screenshot of my supply settings. Should be ok..


----------



## marc02228 (Jan 15, 2011)

my problem seems to be the new charger. The old one works. Now I updated both chargers to 1.10, did a factory reset and loaded the 6OP file from the old charger to the new one.
Still the same error, doesn't matter if I use the PC or not.
Just contacted the cs. 
but if anyone here has an idea, i'd be thankful..


----------



## Batterypoweredtoad (Feb 5, 2008)

Hello all,
I have recently purchased an A123 7s3p module and a 28s3p module and some bare cells and want to go about testing them. Is there a method that lends itself to testing larger numbers of cells than using the PL-6? Any reason more people aren't using the PL-8? If the modules are usable I will order more and build a pack from that, if not I will be stripping out the good cells and hopefully contributing usable information to this thread.


----------



## rwaudio (May 22, 2008)

Batterypoweredtoad said:


> Hello all,
> I have recently purchased an A123 7s3p module and a 28s3p module and some bare cells and want to go about testing them. Is there a method that lends itself to testing larger numbers of cells than using the PL-6? Any reason more people aren't using the PL-8? If the modules are usable I will order more and build a pack from that, if not I will be stripping out the good cells and hopefully contributing usable information to this thread.


Typically we are measuring cell capacity, and the only way to do that accurately is one cell at a time (or parallel cell group). So when testing cells one by one there is no benifit to the PL8 over the PL6. If you just want to balance charge them then the PL8 would have a benefit.


----------



## kerrymann (Feb 17, 2011)

marc02228 said:


> my problem seems to be the new charger. The old one works. Now I updated both chargers to 1.10, did a factory reset and loaded the 6OP file from the old charger to the new one.
> Still the same error, doesn't matter if I use the PC or not.
> Just contacted the cs.
> but if anyone here has an idea, i'd be thankful..


Hmmm... I had to send back one of my 2 PL6s as well but for a different reason. Based on our small set of users it doesn't seem like their QC is top notch...



Batterypoweredtoad said:


> Hello all,
> I have recently purchased an A123 7s3p module and a 28s3p module and some bare cells and want to go about testing them. Is there a method that lends itself to testing larger numbers of cells than using the PL-6? Any reason more people aren't using the PL-8? If the modules are usable I will order more and build a pack from that, if not I will be stripping out the good cells and hopefully contributing usable information to this thread.


The PL6 has the enough power for testing these cells at the 2C rate. The PL8 has the same features, it just has more power that you don't need when testing single cells. There is the possibility of doing multiple cells in series with the balance wires but I don't know anyone who has gotten useful repeatable test data this way. Best of luck.


----------



## Batterypoweredtoad (Feb 5, 2008)

Would the extra power of the PL8 be of any use when testing the 3p groups in the modules? 

Any other sources for the PL6 or 8 anyone here has used successfully? The site linked earlier in the thread is out of stock until May 31st.


----------



## rwaudio (May 22, 2008)

Batterypoweredtoad said:


> Would the extra power of the PL8 be of any use when testing the 3p groups in the modules?
> 
> Any other sources for the PL6 or 8 anyone here has used successfully? The site linked earlier in the thread is out of stock until May 31st.


Nope, they both do 40A max. 

Did you try directly from http://www.revolectrix.com/pl6_description_tab.htm
either the USA or International stores?


----------



## HPEV_llc (Mar 2, 2010)

rwaudio said:


> Some data, capacity and IR for 151 cells. I tested another 60ish with a different method but these are all PL6
> 38A charge to 3.65v terminate C/20
> 38A discharge to 2.25v


So I've been looking at getting a Cellpro PL6 for testing and it looked like it goes to 40 amps max. 

Is there a reason why you were going with 38A instead of 40A for your tests?


----------



## rwaudio (May 22, 2008)

HPEV_llc said:


> So I've been looking at getting a Cellpro PL6 for testing and it looked like it goes to 40 amps max.
> 
> Is there a reason why you were going with 38A instead of 40A for your tests?


Actual capacity of the cells is more like 19Ah, so 38A represents a 2C charge/discharge.


----------



## HPEV_llc (Mar 2, 2010)

rwaudio said:


> Actual capacity of the cells is more like 19Ah, so 38A represents a 2C charge/discharge.


Cool, that's what I was thinking you might have been thinking but I just wanted to make sure it wasn't some limit in the PL6.

I'm glad I found this whole thread and that you and others are deciding to do 2C tests of the cells because that was exactly what I was planning as well.

I find it encouraging that people are still getting 17-19AH at a 2C discharge rate. I'm also curious, has anyone done any tests at a discharge rate of 1C or 0.5C? If so, was there any slight increase in measured AH capacity?


----------



## kerrymann (Feb 17, 2011)

Updated with almost all of my cells. My data very closely matches rwaudios. I came to some interesting conclusions and observations from the testing that I have documented in a procedure/report that I will try to post here tomorrow.


----------



## kerrymann (Feb 17, 2011)

HPEV_llc said:


> Cool, that's what I was thinking you might have been thinking but I just wanted to make sure it wasn't some limit in the PL6.
> 
> I'm glad I found this whole thread and that you and others are deciding to do 2C tests of the cells because that was exactly what I was planning as well.
> 
> I find it encouraging that people are still getting 17-19AH at a 2C discharge rate. I'm also curious, has anyone done any tests at a discharge rate of 1C or 0.5C? If so, was there any slight increase in measured AH capacity?


I have done some testing at 1amp and 10amp and compared to 38amps and there is a pretty significant difference for discharge rates. I also tried different charge rates and found no discernible difference. No surprise discharge rates have a large effect. For instance on one cell:

17.516	1.1	CHARGE 38A, DIS 38A
17.669	1.3	CHARGE 38A, DIS 38A, RETEST
17.624	1.3	CHARGE 10A, DIS 38A
18.419	1.3	CHARGE 10A, DIS 10A

On another cell I tried 2amp and 10 amp and got 18.90ah and 17.80ah! 

I have more data to dig through but my day job and my conversion have been keeping me too busy to play lab tech.


----------



## HPEV_llc (Mar 2, 2010)

Thanks for sharing those differences Kerrymann that was indeed interesting. I am quite interested in these A123 cells for their power capability in such as small and now affordable package. This may finally be the pack that can replace the old Hawkers in my Zilla 2K powered dual motor Fiero.

I am working on a higher wattage discharge testing setup with the CBA and I will have to share the results of some more extreme testing if I can get some higher C rate drains. In the meantime, it looks like a PL6 or PL8 will be the tool for baseline comparisons of the cells and I agree with the 38A rate.


----------



## kerrymann (Feb 17, 2011)

HPEV_llc said:


> Thanks for sharing those differences Kerrymann that was indeed interesting. I am quite interested in these A123 cells for their power capability in such as small and now affordable package. This may finally be the pack that can replace the old Hawkers in my Zilla 2K powered dual motor Fiero.
> 
> I am working on a higher wattage discharge testing setup with the CBA and I will have to share the results of some more extreme testing if I can get some higher C rate drains. In the meantime, it looks like a PL6 or PL8 will be the tool for baseline comparisons of the cells and I agree with the 38A rate.


Your very welcome. One thought I had on higher discharge rates is hooking up multiple PL6s to one cell. I think you could get away without any software changes but it would be really cool if someone (not me) could hack the CCS so you can have multiple PLs act together as one when they are paralleled. I am going overseas for a few weeks for work so I won't be able to play with the idea but maybe someone else out there can give it a shot.


----------



## ev99saturn (May 5, 2009)

I have been testing the cells at a 1C discharge rate on the CBA III tester, not the Powerlab. While this is not apples-to-apples testing with the Powerlab, I can share my data (spreadsheet) if there is interest.

I now have over 200 tested cells, so about half way through my set, charging to 3.60V and discharging to 2.0V.

At 50mph, I expect to be pulling about 0.5C (~9.4A) from each cell, so the 1C discharge adequate for the expected road use. The finished pack will be 4P100S.

The average capacity I am seeing is about 19.5 Ah, with individual cells ranging from 18.9 to 20.2Ah. 

Additionally, an initial set of 10 cells were repeatedly tested for 12-14 cycles each. This showed a trend of increasing capacity as the cells 'break-in'. Not a huge amount, but definitely measureable.

Other testing has been at increasing power load levels, using a resistive load and measuring V, A and temperature rise at the + tab. These tests included both individual cells and a small 2P4S (12V) pack. Tests were at 60A, 120A, 160A, 260A and 370A. At 370A, the cells sag to about 2.5V and remain at that voltage, with only modest warming of the tabs.

Cheers,
Wayne



HPEV_llc said:


> I find it encouraging that people are still getting 17-19AH at a 2C discharge rate. I'm also curious, has anyone done any tests at a discharge rate of 1C or 0.5C? If so, was there any slight increase in measured AH capacity?


----------



## Zak650 (Sep 20, 2008)

In my testing of my cells I ran across one cell that graphed strangely. The powerlab graph shows a fairly normal discharge curve, as it dives toward the bottom it spikes up and then decends again. Has anyone else run accross something like this. Here's the graph:










I've repeated the discharge with the same results 3 times on this one cell.


----------



## HPEV_llc (Mar 2, 2010)

kerrymann said:


> Your very welcome. One thought I had on higher discharge rates is hooking up multiple PL6s to one cell.


On a PL6 is the input isolated from the output?


----------



## HPEV_llc (Mar 2, 2010)

ev99saturn said:


> I have been testing the cells at a 1C discharge rate on the CBA III tester, not the Powerlab. While this is not apples-to-apples testing with the Powerlab, I can share my data (spreadsheet) if there is interest.
> 
> The average capacity I am seeing is about 19.5 Ah, with individual cells ranging from 18.9 to 20.2Ah.
> 
> Other testing has been at increasing power load levels, using a resistive load and measuring V, A and temperature rise at the + tab. These tests included both individual cells and a small 2P4S (12V) pack. Tests were at 60A, 120A, 160A, 260A and 370A. At 370A, the cells sag to about 2.5V and remain at that voltage, with only modest warming of the tabs.


Wayne, Thanks for that information! The slight increase in capacity could be due to the cells being brand new as has been claimed, since that will happen with new cells as they are initially cycled. Then again, my experience has shown any battery pack to get a little better with cycling if it has been sitting un-used for awhile before cycling so it could be just due to that.

I for one would be very interested in seeing your spreadsheet, especially of the higher C-rate discharge tests!


----------



## rwaudio (May 22, 2008)

HPEV_llc said:


> On a PL6 is the input isolated from the output?


The PL6 is not isolated, the input and output ground are connected. It doesn't mean that a couple of them could work in parallel. I've thought about it but haven't tried it yet for fear of blowing them up.


----------



## ev99saturn (May 5, 2009)

Here are the voltages that were observed running higher current loads. For loads up to 160A, the cells were run from fully charged down to 2.0V. For the 260+A loads, discharges were limited to 20 or 30 seconds each.

The readings were taken once the cells hit the flat part of the curve during the discharge.... i.e. after bleeding off the surface charge.

cell amps cell volts C rate 
0 3.34 0
20 3.24 1 
60 3.1 3 
120 2.9 6 
160 2.84 8 
260 2.74 13 
360 2.52 18 
370 2.5 18.5 





HPEV_llc said:


> Wayne, Thanks for that information! The slight increase in capacity could be due to the cells being brand new as has been claimed, since that will happen with new cells as they are initially cycled. Then again, my experience has shown any battery pack to get a little better with cycling if it has been sitting un-used for awhile before cycling so it could be just due to that.
> 
> I for one would be very interested in seeing your spreadsheet, especially of the higher C-rate discharge tests!


----------



## Zak650 (Sep 20, 2008)

Hi,

I don't know how many of you are going to this extend but this is my plan and how I'm doing it.
The purpose is to arrive at as even a capacity pack as possible, that would mean matching the stronges cell in parallel with the weakest eventually meeting in the middle. I'm measuring the capacity of all my cells and writing it down on the cell and recording what plastic carrier it is stored in carrier 1,5,9, etc 4 numbers/carrier. I'm writing this data in column A in a spreadsheet. Then I copy column A's data to another column C. Then I sort column C's data rising numerically and can easily find and match weakest and strongest in pairs to achieve global harmony.


----------



## rwaudio (May 22, 2008)

Zak650 said:


> Hi,
> 
> I don't know how many of you are going to this extend but this is my plan and how I'm doing it.
> The purpose is to arrive at as even a capacity pack as possible, that would mean matching the stronges cell in parallel with the weakest eventually meeting in the middle. I'm measuring the capacity of all my cells and writing it down on the cell and recording what plastic carrier it is stored in carrier 1,5,9, etc 4 numbers/carrier. I'm writing this data in column A in a spreadsheet. Then I copy column A's data to another column C. Then I sort column C's data rising numerically and can easily find and match weakest and strongest in pairs to achieve global harmony.


I've done basically the same thing in an excel spreadsheet. I don't just match the lowest with the highest, I set a target total value and move cells around to get them within +/-0.01Ah this leaves the "error" with the consistency of the PL6 in testing. I group the cells into A,B,C.... groups so that I get the correct cells in the 3P set up. I then have 4 groups that make up a module, I am assembling these into 4S3P modules that are still light and easy to work with. At the far right I have my module type which tells me what type of terminals that I need to use for proper assembly of the pack. C,D are my large terminals that will accept a 2/0 lug, A,B are simply threaded/non threaded versions of the same connection block. (module 24 will be the type C version for the other 2/0 lug)
My complete pack will be obviously 24 modules in the end.


Group	Module Cells Total	Variance Module type	
A	1	17.860	18.880	19.260	56.00	0.00	D
B	1	17.890	18.590	19.520	56.00	0.00	D
C	1	17.920	18.610	19.470	56.00	0.00	D
D	1	17.990	18.620	19.390	56.00	0.00	D
E	15	18.080	18.620	19.300	56.00	0.00	A
F	15	18.150	18.650	19.200	56.00	0.00	A
G	15	18.060	19.250	18.700	56.01	0.01	A
H	15	18.280	18.690	19.030	56.00	0.00	A
I	2	18.310	18.690	19.000	56.00	0.00	B
J	2	18.330	18.690	18.980	56.00	0.00	B
K	2	18.330	18.700	18.970	56.00	0.00	B
L	2	18.410	18.780	18.810	56.00	0.00	B
M	3	18.440	18.790	18.770	56.00	0.00	A
N	3	18.440	18.790	18.770	56.00	0.00	A
O	3	18.470	18.800	18.730	56.00	0.00	A
P	3	18.490	18.800	18.710	56.00	0.00	A
Q	4	18.500	18.810	18.690	56.00	0.00	B
R	4	18.400	18.770	18.830	56.00	0.00	B
S	4	18.560	18.920	18.520	56.00	0.00	B
T	4	18.560	18.920	18.520	56.00	0.00	B
U	5	18.560	18.930	18.510	56.00	0.00	B
V	5	18.560	18.930	18.510	56.00	0.00	B
W	5	18.560	18.940	18.500	56.00	0.00	B
X	5	18.510	18.840	18.650	56.00	0.00	B
Y	6	18.550	18.900	18.550	56.00	0.00	A
Z	6	18.550	18.910	18.540	56.00	0.00	A
AA	6	18.270	19.180	18.550	56.00	0.00	A
BB	6	18.400	19.190	18.410	56.00	0.00	A
CC	7	18.390	19.020	18.590	56.00	0.00	B
DD	7	18.260	19.010	18.730	56.00	0.00	B
EE	7	18.360	19.310	18.330	56.00	0.00	B
FF	7	18.250	18.600	19.150	56.00	0.00	B
GG	8	18.000	18.840	19.160	56.00	0.00	B
HH	8	19.190	19.210	17.600	56.00	0.00	B
II	8	18.130	18.870	19.000	56.00	0.00	B
JJ	8	18.670	18.610	18.720	56.00	0.00	B
KK	9	19.050	18.370	18.570	55.99	-0.01	A
LL	9	17.910	18.880	19.210	56.00	0.00	A
MM	9	19.120	18.920	17.950	55.99	-0.01	A
NN	9	18.750	18.620	18.620	55.99	-0.01	A
OO	10	19.170	17.660	19.160	55.99	-0.01	B
PP	10	19.120	17.720	19.160	56.00	0.00	B
QQ	10	18.620	18.640	18.740	56.00	0.00	B
RR	10	18.590	18.520	18.880	55.99	-0.01	B
SS	11	19.140	17.700	19.160	56.00	0.00	B

Sorry for the formatting but it should give you the idea.


----------



## GerhardRP (Nov 17, 2009)

kerrymann said:


> No surprise discharge rates have a large effect. For instance on one cell:
> 17.516	1.1	CHARGE 38A, DIS 38A
> 17.669	1.3	CHARGE 38A, DIS 38A, RETEST
> 17.624	1.3	CHARGE 10A, DIS 38A
> 18.419	1.3	CHARGE 10A, DIS 10A


I wonder if you could do this test: Discharge at 38A to cutoff; rest for, say 15 minutes, then continue at 10A. What is the total capacity?
Gerhard


----------



## kerrymann (Feb 17, 2011)

The procedure is attached. 

Sorry for the long delay. I finished this over a month ago. I wanted to put a lot more information and lessons learned from testing into this but am too busy with the build. That and I had to strip some stuff out to make the .pdf small enough to attach it here. Anyway I hope people find it useful. And it would be great to start seeing other people's data.

Enjoy,


----------



## GerhardRP (Nov 17, 2009)

kerrymann said:


> The procedure is attached.
> 
> Sorry for the long delay. I finished this over a month ago. I wanted to put a lot more information and lessons learned from testing into this but am too busy with the build. That and I had to strip some stuff out to make the .pdf small enough to attach it here. Anyway I hope people find it useful. And it would be great to start seeing other people's data.
> 
> Enjoy,


Are you keeping the cells under a standard compression to keep them from swelling under abuse during testing and proposed use?


----------



## marc02228 (Jan 15, 2011)

I don't know, how kerrymann does it. 
I put a book under the cell, another book over the cell and some heavy thing, e.g. a toolbox (4kg) onto this book-cell-sandwich.

My cells don't get weak during the 2C charge, so I just do it when the cell is discharging. It definitely isn't as weak as it is without pressure on it during the discharge.


----------



## kerrymann (Feb 17, 2011)

GerhardRP said:


> Are you keeping the cells under a standard compression to keep them from swelling under abuse during testing and proposed use?


Good question. Originally I was using a book with a 30lb SLA battery on top for the tests but I about half way to I tried it without the weight with no issues. For in my car I have made end plates that will be clamped together with long band clamps to provide compression. Similar to the original A123 packs.


----------



## ellweber (Jun 3, 2009)

kerrymann said:


> And it would be great to start seeing other people's data.


kerrymann,

I have the first 12 of a 300 cell planned pack and I am trying to follow your procedure and use rwaudios preset with my PL6. When trying to add data to the 5-23 version of your spreadsheet I cannot find the Analysis Tab's pull down. I am using Excel 2008 on a Mac.

Can you provide some more clues on the use of this please.

Best regards,

ellweber


----------



## marc02228 (Jan 15, 2011)

How can I add data without erasing the gray line?
Here are all tested cells:
1	1	0,9
2	1	0,8
3	1	0,8
4	1	0,8
5	1	0,8
6	1	0,8
7	1	0,8
8	1	0,7
9	18200	0,8
10	18095	0,9
11	18593	0,8
12	18739	0,8
13	17666	0,8
14	17823	0,8
15	18317	0,8
16	18347	0,8
17	17781	0,8
18	17848	0,8
19	18020	0,8
20	18214	0,8
21	17754	0,7
22	17982	0,7
23	17919	0,8
24	18600	0,7
25	18807	0,8
26	18754	0,8
27	18621	0,6
28	18608	0,7
29	18290	0,7
30	18601	0,7
31	18512	0,6
32	17811	0,8
33	18849	
34	18709	0,7
35	18653	0,7
36	18637	0,6
37	17740	0,7
38	17701	0,8
39	18260	0,7
40	18206	0,7
41	17802	0,7
42	18267	0,7
43	17943	0,7
44	18791	0,7
45	18437	0,7
46	18585	0,8
47	18378	0,8
48	18425	0,8
49	18486	0,8
50	17967	1,3
51	18391	0,7
52	18524	0,6
53	18324	
54	17678	1,1
55	18119	
56	18838	0,9
57	18003	0,8
58	18022	0,7
59	17999	0,8
60	17430	0,8
61	17870	0,7
62	17865	0,7
63	17647	0,7
64	17874	0,7
65	18511	0,7
66	18373	0,7
67	18533	0,6
68	18926	0,7
69	18893	0,6
70	18969	0,7
71	18827	0,7
72	18655	0,7
73	18532	
74	18751	
75	18723	0,7
76	18651	0,8
77	18656	0,8
78	18824	
79	18439	
80	18332	0,7
81	18332	0,7
82	18133	
83	18136	0,7
84	18438	0,7
85	18683	
86	18574	
87	18472	0,7
88	18385	0,9
89	18159	0,8
90	18234	0,8
91	18006	0,8
92	18423	0,8
93	17913	0,8
94	18401	0,8
95	18021	0,8
96	17845	0,8
97	18421	0,8
98	18390	0,8
99	18202	0,8
100	18238	0,8
101	18450	0,8
102	18184	0,8
103	18428	0,8
104	18550	0,8
105	18603	0,8
106	18710	0,8
107	17963	0,8
108	18291	0,7
109	18347	0,9
110	18260	0,8
111	18417	0,8
112	18377	0,8
113	18431	0,7
114	18917	0,6
115	18652	0,7
116	18787	0,7
117	18472	0,8
118	18525	0,8
119	18634	0,9
120	18787	0,8
121	18594	0,7
122	18872	0,7
123	18244	0,8
124	18641	0,7
125	18648	0,7
126	18606	0,8
127	18226	0,8
128	18130	0,7
129	18530	1,1
130	18232	0,9
131	18450	0,9
132	18947	0,8
133	18730	0,8
134	18859	0,8
135	18296	0,8
136	18323	0,8
137	18600	0,7
138	18266	0,7
139	18447	0,8
140	18561	0,8
141	18309	0,8
142	18184	0,8
143	18606	0,8
144	18242	0,7
145	18500	0,8
146	18732	0,8
147	18616	0,8
148	18599	0,7
149	18517	0,8
150	18461	0,8
151	18262	0,9
152	18252	0,9
153	17636	0,8
154	18032	0,7
155	17799	0,8
156	17788	0,8
157	18603	0,8
158	18314	0,8
159	18210	0,8
160	18660	0,7
161	18433	0,8
162	18410	0,8
163	18322	1
164	18398	0,7
165	18577	0,9
166	18449	0,9
167	18409	0,8
168	18199	0,7
169	18396	0,8
170	18283	0,8
171	18058	0,8
172	17931	0,8
173	17970	0,8
174	18046	0,8
175	18353	0,8
176	17623	0,8
177	18097	0,7
178	18024	0,8
179	17997	0,7
180	18227	0,7
181	18022	0,8
182	18035	0,8
183	18350	0,8
184	18006	0,8
185	18313	0,8
186	18254	0,8
187	18016	0,8
188	18112	0,7
189	18395	0,8
190	17953	0,7
191	18349	0,8
192	18534	0,8
193	18103	0,8
194	18160	0,8
195	18492	0,8
196	18140	0,7
197	18528	0,7
198	18329	0,9
199	18535	0,8
200	18402	0,8
201	18636	0,7
202	18501	0,8
203	18153	0,8
204	17754	0,8
205	18387	0,9
206	18022	1,2
207	18659	0,8
208	18498	0,8
209	18443	0,8
210	18594	0,8
211	18826	0,7
212	18804	0,8
213	18630	0,8
214	18559	0,8
215	18247	0,8
216	18203	0,7
217	18078	0,8
218	18210	
219	18311	0,7
220	18329	0,8
221	18180	0,8
222	18139	
223	18081	
224	18480	0,8
225	18129	0,8
226	18698	0,8
227	18433	0,9
228	18513	0,9
229	18652	0,8
230	18544	0,7
231	18446	
232	18427	0,7
233	18161	0,8
234	18239	0,8
235	18190	0,8
236	18339	0,8
237	18553	0,8
238	18373	0,8
239	18055	0,8
240	18475	0,8
241	18403	0,8
242	18891	0,8
243	18386	0,8
244	18084	0,8
245	18172	0,8
246	17907	0,9
247	18339	1
248	17828	1
249	18819	0,7
250	18737	0,7
251	18510	0,8
252	18739	0,7
253	18145	0,9
254	17899	0,8
255	18039	0,9
256	18011	0,9
257	17953	0,8
258	18299	0,8
259	17989	0,7
260	18185	0,8
261	18225	0,8
262	18144	0,8
263	18402	0,7
264	18320	0,7
265	18320	0,7
266	18671	0,6
267	18532	0,7
268	18893	0,7
269	18923	0,7
270	18953	0,7
271	18762	0,7
272	18770	0,7
273	18666	0,7
274	18757	0,7
275	18575	0,7
276	18681	0,7
277	18804	0,7
278	18776	0,8
279	17976	0,8
280	17927	0,7
281	18565	0,7
282	18686	0,7
283	18813	0,6
284	18725	0,6
285	18774	0,6
286	18893	
287	18732	
288	18647	0,7
289	18193	0,7
290	18330	0,7
291	18438	0,7
292	18167	
293	18432	
294	18334	0,7
295	1	4K
296	1	4K
297	18385	0,8
298	18001	0,8
299	17999	0,7
300	17696	0,7
301	18290	0,9
302	18789	1,2
303	18399	0,8
304	18183	0,8
305	18314	0,7
306	18065	0,7
307	18241	0,7
308	18277	0,7
309	18321	0,7
310	17883	0,8
311	18151	0,8
312	18196	0,8
313	18302	0,8
314	18425	0,8
315	18515	0,8
316	18698	0,7
317	18593	0,8
318	18829	0,7
319	18348	0,7
320	18428	0,8
321	18775	0,8
322	18902	0,8
323	18224	0,8
324	18544	0,7
325	18342	0,7
326	18308	0,8
327	18427	0,8
328	18420	0,8
329	18451	
330	18724	
331	18697	
332	18471	
333	18361	
334	18406	
335	18111	
336	18108	
337	18192	
338	18113	
339	18695	
340	18064	
341	18054	
342	18595	
343	18126	
344	18003	
345	1	
346	18353	0,8
347	17770	0,7
348	18077	0,8
349	18047	0,7
350	17718	0,8
351	17831	0,8
352	17930	0,8
353	17746	0,8
354	18089	0,8
355	17975	0,8
356	18324	0,8
357	18130	0,8
358	1	
359	18453	0,9
360	18521	0,9
361	18369	
362	18811	0,6
363	18393	0,8
364	18480	
365	18331	0,8
366	18499	0,8
367	18247	0,8
368	17914	0,8
369	18035	0,8
370	18227	0,8
371	18350	0,8
372	18320	0,7
373	18045	0,8
374	18275	0,8
375	17801	0,8
376	17806	0,8
377	17904	0,8
378	17900	0,8
379	18516	0,8
380	18482	0,8
381	18612	0,7
382	18848	0,7
383	18678	0,7
384	18665	0,7
385	18951	0,8
386	19055	0,8
387	18064	0,8
388	18014	0,8
389	18867	0,8
390	18774	0,8
391	18652	0,8
392	18528	0,7
393	18352	0,8
394	18347	0,8
395	17900	0,8
396	18182	0,8
397	17934	0,8
398	17803	0,8
399	18266	0,8
400	17865	0,8
401	18303	0,8
402	18234	0,8
403	17768	0,8
404	18278	0,7
405	18355	0,8
406	18514	0,8
407	17786	0,8
408	17638	0,7
409	17919	0,8
410	17940	0,8
I set he capacity of some cells to 1. These are test cells or cells in bad condition, I didn't want to have in my pack.

I matched the cells using a python script. Total 3P capacity varies from 55434 to 55429mAh.


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## Ziggythewiz (May 16, 2010)

Cool, can you post the script? We were trying to figure that out a while ago and aside from brute forcing didn't get much better than reverse pairing.


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## kerrymann (Feb 17, 2011)

ellweber said:


> kerrymann,
> 
> I have the first 12 of a 300 cell planned pack and I am trying to follow your procedure and use rwaudios preset with my PL6. When trying to add data to the 5-23 version of your spreadsheet I cannot find the Analysis Tab's pull down. I am using Excel 2008 on a Mac.
> 
> ...


It's been at few months since I looked at the excel to remember off the top of my head I am but glad to hear people are interested in using it. I had pretty much given up on the idea. I am on the road this weekend but when I get back I'll take a look.


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## ellweber (Jun 3, 2009)

kerrymann said:


> It's been at few months since I looked at the excel to remember off the top of my head I am but glad to hear people are interested in using it. I had pretty much given up on the idea. I am on the road this weekend but when I get back I'll take a look.


Thanks for looking at this. I don't want to cobble up the spreadsheet and upload it if I have something set up wrong! I can get it to show my own data and it is very helpful but we should try keep it more universal so the body of data is as big as possible.

I have already learned a bit about the 12 cells I received, they are surprisingly consistent in their performance (so far).


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## marc02228 (Jan 15, 2011)

Attached you see the Python script I used to match the cells.

Just put the capacity of your single cells starting with cell #1 into kapazitaet.txt.

Change the value of "dreierpack_n" to set your needed cells in series.

The script is written for 3 cells in parallel. 

It looks for the best capacities and matches them to packs trying to get the same total capacity. 

Run it a couple times and keep saving the last respectively best result. If it has a bad start, the capacities might vary more then if you start it some more times. 

When it's done, it gives you the matched cell numbers in square brackets and below the total capacity of the paralleled cells.

Looks like this:



> #of cells in parallel: [[70, 399, 168], [27, 381, 9], [286, 189, 262], [283, 224, 222], [116, 94, 123], [317, 166, 98], [269, 185, 312], [318, 265, 170], [272, 380, 221], [271, 293, 100], [214, 324, 198], [322, 16, 304], [85, 101, 258], [302, 195, 311], [242, 247, 99], [274, 88, 29], [68, 109, 89], [360, 364, 113], [25, 359, 245], [120, 150, 142], [119, 147, 396], [213, 314, 112], [69, 303, 196], [210, 52, 158], [287, 346, 394], [133, 363, 141], [148, 45, 169], [114, 297, 357], [71, 87, 82], [77, 231, 290], [249, 205, 127], [132, 39, 261], [276, 232, 53], [281, 104, 15], [207, 328, 175], [28, 97, 241], [382, 136, 110], [143, 92, 200], [134, 319, 323], [288, 164, 243], [30, 202, 220], [124, 145, 301], [211, 401, 313], [212, 208, 225], [146, 51, 326], [72, 327, 191], [250, 393, 325], [137, 251, 309], [383, 11, 194], [33, 264, 151], [226, 263, 365], [24, 366, 81], [362, 66, 215], [122, 372, 234], [389, 163, 144], [390, 139, 218], [34, 105, 55], [56, 167, 102], [12, 48, 42], [74, 79, 307], [266, 67, 370], [26, 209, 90], [229, 73, 367], [78, 80, 374], [149, 49, 103], [115, 162, 361], [384, 240, 108], [106, 46, 83], [252, 291, 186], [270, 219, 292], [391, 121, 260], [278, 320, 180], [284, 237, 203], [385, 371, 128], [277, 315, 188], [44, 131, 235], [321, 47, 404], [76, 86, 40], [285, 31, 253], [125, 161, 183], [126, 392, 135], [35, 65, 138], [75, 406, 289], [157, 275, 152], [140, 129, 236], [230, 228, 238], [36, 379, 308], [386, 20, 233], [268, 294, 216], [282, 192, 159], [273, 267, 130], [118, 117, 227], [316, 111, 305], [160, 199, 402], [201, 84, 405], [165, 197, 356]]
> Sum of cells in parallel: [55434, 55433, 55432, 55432, 55432, 55432, 55432, 55432, 55432, 55432, 55432, 55432, 55432, 55432, 55432, 55432, 55432, 55432, 55432, 55432, 55432, 55432, 55432, 55432, 55432, 55432, 55432, 55432, 55432, 55432, 55432, 55432, 55432, 55432, 55432, 55432, 55431, 55431, 55431, 55431, 55431, 55431, 55431, 55431, 55431, 55431, 55431, 55431, 55431, 55431, 55431, 55431, 55431, 55431, 55431, 55431, 55431, 55431, 55431, 55431, 55431, 55431, 55431, 55431, 55431, 55431, 55431, 55431, 55431, 55431, 55431, 55431, 55431, 55431, 55431, 55431, 55431, 55431, 55431, 55431, 55430, 55430, 55430, 55430, 55430, 55430, 55430, 55430, 55430, 55430, 55430, 55430, 55429, 55429, 55429, 55429]
> Exit status: 0
> logout
> ...


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## ellweber (Jun 3, 2009)

I have completed preliminary testing of the first 12 cells I received and wanted to share the results. The attachments should be self-explanatory. Overall I have been pleased with the measured performance of these cells and am very appreciative of all the pioneering work that has been done here that allowed me to get some meaningful data quickly.

I think that the parasitic contributions of the test set-up may be contributing significantly to test data variability. In my test fixture there is more voltage drop (at 38 amps) across the two fuses than in the wires and cell tab pressure contacts combined! Also, there is clearly some temperature dependence of the cell's internal resistance and capacity and the PL6 does some unexplained things occasionally too.


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## kerrymann (Feb 17, 2011)

ellweber said:


> kerrymann,
> 
> I have the first 12 of a 300 cell planned pack and I am trying to follow your procedure and use rwaudios preset with my PL6. When trying to add data to the 5-23 version of your spreadsheet I cannot find the Analysis Tab's pull down. I am using Excel 2008 on a Mac.
> 
> ...


Are you saying you can't open the Analysis Tab? If you mean you can't find your user name you'll have to copy a column and add in your name.



marc02228 said:


> How can I add data without erasing the gray line?
> Here are all tested cells:
> 
> I set he capacity of some cells to 1. These are test cells or cells in bad condition, I didn't want to have in my pack.
> ...


Just insert a new row. I just usually copy and insert cells that are already there and overwrite with your new data. I went ahead and added your rows but it needs some clean up. Were the cells with the capacity of 1ah dead? or did you get a low value? 

The comma's instead of period for a decimal point wouldn't work on my machine and didn't feel like cleaning it up.

Also your data was in milliamp hours, where everything else is in ah so I just divided by 1000.

Thanks guys and I hope that helps!


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## ellweber (Jun 3, 2009)

kerrymann said:


> Are you saying you can't open the Analysis Tab? If you mean you can't find your user name you'll have to copy a column and add in your name.



I can do all that and _I can open the analysis tab_ but I read your instruction number 4 "...To compare your results with other users select them from the pull downs..." to suggest there was some more automation of this. I cannot find any pull downs on the Analysis Tab, only on the Test Data tabs. 

I will go ahead and enter my info directly.

Thanks,

Lynn


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## kerrymann (Feb 17, 2011)

ellweber said:


> I can do all that and _I can open the analysis tab_ but I read your instruction number 4 "...To compare your results with other users select them from the pull downs..." to suggest there was some more automation of this. I cannot find any pull downs on the Analysis Tab, only on the Test Data tabs.
> 
> I will go ahead and enter my info directly.
> 
> ...


Ahhh.... I understand now. The pull downs are C2, D2, and E2, If you entered your name on the first tab then it will show up on the pull down located on these cells. I will update the instructions to clarify this.


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## kerrymann (Feb 17, 2011)

ellweber said:


> I have completed preliminary testing of the first 12 cells I received and wanted to share the results. The attachments should be self-explanatory. Overall I have been pleased with the measured performance of these cells and am very appreciative of all the pioneering work that has been done here that allowed me to get some meaningful data quickly.
> 
> I think that the parasitic contributions of the test set-up may be contributing significantly to test data variability. In my test fixture there is more voltage drop (at 38 amps) across the two fuses than in the wires and cell tab pressure contacts combined! Also, there is clearly some temperature dependence of the cell's internal resistance and capacity and the PL6 does some unexplained things occasionally too.


Nice set-up and data. I like the clamps in plate of my bolt and blocks. I assume you got them from Carr-lane or McMaster? In my set-up I didn't put in any fuses but I am surprised at that much resistance in the fuses. How much dV did you get across the fuse? 

I completely agree with the last sentence. Sometimes the PL6 just acts weird. How much time was there between the first and second tests of the same cell? Whenever I repeated a test on a cell I would let it sit for a few hours to come back to ambient temperature. 

Also, like you, I always found the first test of a cell was the ah lowest reading. My two best guess are the the first time you are "breaking in" the cell and the second is the cell being warmer on the subsequent tests. When you first test a cell it is about 50-75% charged so you are not having to put much into it to get it to 100% before the discharge cycle. For the subsequent tests you are completely charging the cell at 2C right before the discharge which means the cell is 10-20° warmer then ambient. The definitive answer on the second would be to charge a cell to 75% cool and then repeat the test. This winter I plan on doing more experiment cell testing and will try it out. I want to get another 100 cells but now that victpower is no longer taking Paypal (T/T only) I am more nervous about sending them money and just crossing my fingers....


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## GerhardRP (Nov 17, 2009)

Hi
A couple of corrections:

"Analysis"! G3 should be 
=COUNTIF('Test Data'!K2:K824,">0")

"Analysis"! H3 [etc3] should be
=COUNTIFS('Test Data'!$A$2:$A$824,H$2,'Test Data'!$K2:$K824,">0")

Chart 1 caption: milliOhm

Gerhard


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## ellweber (Jun 3, 2009)

Kerry,

Nothing fancy for the toggle clamps, ~$6 each at Harbor Freight! I am seeing about 10 mv +/- across the tab pressure clamps. I am using 0.010" brass shim stock for contacts and I can keep the drop down to 5 mv if I am rigorous about cleaning the surfaces. The two fuses (ATX or "Maxi") are about 80 mv each and the #8 wire about 80 mv altogether. All this at 38 amps.

I do think the PL6 weirdness has diminished with the S/W upgrade to V1.10. I have experimented with testing warmer and cooler and do not see a huge difference. The cells themselves seem to be incredibly efficient in terms of A-hr in vs. A-hr out. The self heating mostly occurs when the voltage-time curve gets steeper during end of charge or end of discharge. I do not see much temperature rise when the cells are between 3.3 and 3.0 volts discharging or between 3.3 and 3.4 volts charging.

I think the first few cycles must be migrating impurities out of the interstices of the electrodes (or something equally mystical!) and then things start to get dirty again with lots of cycles. The cells seem to like to be at ~35 degrees C. The Ir comes to equalibrium faster and the performance seems slightly more reproducible.

I am going to build these 12 cells into a 4s3p pack and then I won't have to fight my clunky old Pb car battery as a temperamental source supply when the next 300 cells arrive.

I have been pleased with Victpower/Xin so far. They seem responsive and have met commitments. I used PayPal for the first 12 cells but have wired the balance. I don't know whether that constitutes bravery, confidence, faith or stupidity. Ask me in two weeks!

I have added my initial data to the spreadsheet attached. I hope I haven't done too much damage. I still don't see any pull downs on the analysis tab.

Lynn


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## novatin (Mar 30, 2010)

Hello.

I´ve been trying to test my A123 20Ah cells but all I can obtain is 7.8 mOhms instead of 0.7 -1 like others.

Any idea?

Thanks.


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