Duchess Powerwall build log (56k warning!)

Well sure you can swap out single cells but that would change the parameters of the the other cells when doing so! What a stupid design. If you swap out 1 cell then you have to reset the test (NOR test) for the rest of the cells and start all over with the rest of the cells!! So its either test 1 cell at a time or wait for all 4 to get done. That's dumb.
What? Oh my, mine don't change anything, I have 3 units but not the problem you say... I would have gone mad testing 1200 cells with the problem you say... maybe you have some other strange problem (?).

And I do keep an eye on timing, it always takes more or less the same time for similar cells.

There is a bug (Microsoft would call It a feature) that changes parameters if you quickly insert 4 cells in an empty unit: the settings of a cell influence previous cell but only in one direction (if I remember right It happens when quickly inserting cells from slot 1 to 4).
 
Lets say you have all 4 cells inserted doing a NOR test. Cell #3 is done testing. You swap out cell#3 for a different one and press the mode button twice to select NOR test. The cells in 1,2 and 4 were on NOR test but since you pressed the mode button twice for cell #3, 1,2 and 4 have now changed from NOR test to CHARGING then Quick Test and start all over again. If you were to then press the mode button again on 1,2 or 4 to select NOR test again.... cell #3 moves 2 modes to Quick Test. What a stupid design. The ZanFlare ones you can at least change the mode on 1 cell without changing the parameters of the others.

I fought with them for a while until I gave up and tossed them. It would take me all day to just test 30 cells when I can get about 100 done a day with the ZanFlare devices.
 
This should be enough to start off right? More?

1628878814274.png
 
This should be enough to start off right? More?

View attachment 25835
Good start! But what I did is to test all cells (1120 for four 2.5KWh batteries) before building. That's because I want to make all parallel blocks more similar as possible and I could only do that after testing all cells.

For your charger problem I can tell you that mine don't have it. If I swap out a cell when NOR test Is finished and put a new Cell in, settings don't influence other slots. Could be maybe a newer firmware, I can't think of other reasons.
 
Each cell is tested, stored for about a month and tested again before assembling into small packs using repacker. Each pack is then tested for capacity and stability. I have a pretty sophisticated testing procedure. I haven't really found a retail device (charger/tester) that can properly do IR and or accurate voltage readings for the cells.
 
I haven't really found a retail device (charger/tester) that can properly do IR and or accurate voltage readings for the cells.
That's because there isn't one. All retail (charger/tester)s use a voltage drop against a known resistor value for their"IR" test. There is no way to properly test for IR/Impedance other than the 4 wire kelvin methode. To get a proper IR and Voltage reading an YR1035+, a RC3563 or equivalent is needed.
Wolf
 
That's because there isn't one. All retail (charger/tester)s use a voltage drop against a known resistor value for their"IR" test. There is no way to properly test for IR/Impedance other than the 4 wire kelvin methode. To get a proper IR and Voltage reading an YR1035+, a RC3563 or equivalent is needed.
Or a HP4263a. 😉
 
Or a HP4263a
Yes absolutely a HP4263a or better yet a Keithley DMM7510. For those that have the means to purchases these, more power to them.
The YR1035+ and /or the RC3563 are at a much more reasonable cost being sub $100.00 and quite accurate. ;)
Additionally with the cell holders and especially the RC3563s serial interface, with a little python code and a VB script, the values can be easily machine recorded to eliminate input errors.
Fat finger syndrome and eye fatigue when recording the voltage and IR of 200+ cells at a whack.:p
I have a pretty sophisticated testing procedure
Do share for the benefit of the community as we are all trying to learn.:)
Wolf
 
@Duchess was it something I said?
I wish you luck with your build and we are all looking forward to your progress.
Wolf
 
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