Juanjo Madrid's cell replacement thread

[Juanjo Madrid]

But one think is real, with the diagram of Kiev cells 88 is connected to 77, not is possible 77 to 84 and 85 to 88 are flipped

 

[kiev]

Does not the buss bar go from CMU11 Cell A -to- CMU12 Cell D? i can see it in your picture.

 

[kiev]

If the cell contact pad is damaged on one cell, then it can affect the voltage reading by the CAN buss of the neighbor also because the voltage reading is referenced with respect to the neighbors too.

 

[piev]

But one think is real, with the diagram of Kiev cells 88 is connected to 77, not is possible 77 to 84 and 85 to 88 are flipped

I believe the 4 cell modules are on the wrong side in this schematic.

in the picture below you can see the battery disable plug it is orange. That plug is under the drivers seat. Front left on an American vehicle.
The schematic says that is CMU7, so CMU12 is next to Module 11 moving across the middle. CMU6 is then next to CMU1 across the middle from CMU5.

So in the picture below. Bottom left module is 1.
Front-->
5--6-------------Plug---7
4------------------------8
3------------------------9
2-----------------------10
1--12-------------------11

 

[MickeyS70]

Looks like we won’t be able to convince @Juanjo Madrid that the schematics is correct? Unfortunately not much else to do than hope he has a change of heart and swaps the right cells…

 

[Juanjo Madrid]

¿La barra colectora no va desde la celda A de CMU11 hasta la celda D de CMU12? Puedo verlo en tu imagen.
View attachment 1494

Yes Kiev, CMU 11 is connected to CMU12, them cell #77 is connected to cell #88 and this is not possible, I think the #77 is #84 in real and the #88 is #85 in real, you can see in my pictures and in other pictures, I think are flipped all packages in the diagram.

 

[Juanjo Madrid]

Looks like we won’t be able to convince @Juanjo Madrid that the schematics is correct? Unfortunately not much else to do than hope he has a change of heart and swaps the right cells…

Thank you for trying MickeyS70, maybe some thing Im loosing with my poor english, but the reality and the busbar, the ohmmeter, pictures, etc... are more strong than your words, LOL. 77 not is possible to be connected to 88, some is wrong in first Kiev 2022 diagram, confirmed by my eyes and tester, and other pictures in web sites and this forum, I think CMU 11 and CMU6/CMU12 numbers are placed where is in diagram, but not the cell numbers, are flipped and you can see in all the pictures simply following busbar white lines: I think 77 cell is 84 cell, 78/83, 79/82 80/81, 81/80, 82/79, 83/78 and finally 84 is 77, this on CMU11 (and all the others CMU are flipped them from CMU 1 to 10) and in CMU12: 88 is 85 (84 and 85 them are connected ok in my picture), 87/86 86/87 and finally 85 is 88 ( and them this final cell entry y connection black box in middle of package).

I have two CATL 93Ah cells too, 4 replaced and dismantling cells in total (2 Lev50N with 1 miliOhm and 2 CATL 93Ah with 0,5 miliohm) do you recommend to my change others loose voltage cells?
Thanks again,
Juanjo.

 

[kiev]

For every Cell Module (CM01 thru CM12) the most positive cell is called "A". This is the convention in the FSM and in the MUT used for diagnostics.

It is also the lowest numbered cell in the counting sequence for each Module when voltage is reported over the CAN buss. The cells are reported in order, from highest to lowest voltage,
A-B-C-D-E-F-G-H

As a result of this convention and reporting sequence, the bottom of the Pack, the most negative cell, is CM01 "H" cell #8. And the top of the Pack, the most positive cell, is CM12 "A" cell #85.

The series electrical connection of the cells does not follow a normal counting sequence. It follows an alphabetical sequence, the numbers are added by the CAN buss/Apps to give unique identifiers for cells, but their numerical sequence is not related to their electrical sequence.

The "numbers" are not really numbers for counting, they are just labels that happen to use numerals instead of letters. A computer thing.

 

[MickeyS70]

Thank you for trying MickeyS70, maybe some thing Im loosing with my poor english, but the reality and the busbar, the ohmmeter, pictures, etc... are more strong than your words

Nothing wrong with your English, but you don’t seem to accept that cell numbering isn’t following the electrical connections (as @kiev mentioned multiple times)

I understand you need to see to believe therefore I suggest to do this now (or take the risk of having to re-do all the work later):

Swap one of your unbalanced CATL cell into the position you think 86 should be, leave the lid open, move the pack close enough to the car that you can make the data connections only (no need for HV cables), make sure airbag plug under the driver seat is closed, connect 12V aux and turn on, then check voltage diagram with OBDZero and see where it shows up…

have two CATL 93Ah cells too, 4 replaced and dismantling cells in total (2 Lev50N with 1 miliOhm and 2 CATL 93Ah with 0,5 miliohm) do you recommend to my change others loose voltage cells?

It’s generally not recommended to mix cells chemistries, however beggars can’t be choosers and the CATL93 are within the LEV50 voltage range, therefore it’s OK to use them imho.

But from experience of others, swapping any ‘new’ cells into a degraded pack will only fix the problem temporary as more of the remaining cells will go ‘weak’ over time and the cycle starts again..

 

[Juanjo Madrid]

Para cada módulo celular (CM01 a CM12), la celda más positiva se denomina "A". Esta es la convención que se utiliza en el FSM y en el MUT para los diagnósticos.

También es la celda con el número más bajo en la secuencia de conteo de cada módulo cuando se informa el voltaje a través del bus CAN. Las celdas se informan en orden, desde el voltaje más alto hasta el más bajo.
A B C D E F G H

Como resultado de esta convención y secuencia de informes, la celda inferior del Pack, la más negativa, es la celda CM01 "H" n.° 8. Y la celda superior del Pack, la más positiva, es la celda CM12 "A" n.° 85.

La conexión eléctrica en serie de las celdas no sigue una secuencia de conteo normal.

Ok, thanks for help me, the 77 is connected to 88, 1 to 16, 9 to 24, 17 to 32, 25 to 40, 33 to 44, 41 across the main fuse to 52, 45 to 50, 53 to 58, 61 to 76 and 69 to 84... and the first one cell in the string is the number 8 and the last one is the 85, I think a fuse in the Middle of string and this numbering are crazy but is the numbering

I thinking buy in future 88 used LEV50N cells if the price are under 20$, and sustitute my full package, the first two used LEV50N look well, 1 miliOhm instead of my 2,5mOhm cells and around 40Ah measured.

I have a UPS of 5KVa waiting my best used cells to do packages of 36V (32 cells 2P8S) packages, I thinking put in rear of my Twizy to do a 60 Kg Extender at 220V (charging when stopped), to do 3 Kwh (cells at 50% of capacity), my daily spend , 26Km in a Twizy.

 

[MickeyS70]

this numbering are crazy but is the numbering

Hallelujah

I thinking buy in future 88 used LEV50N cells if the price are under 20$, and sustitute my full package, the first two used LEV50N look well, 1 miliOhm instead of my 2,5mOhm cells and around 40Ah measured.

Have you thought of replacing the complete pack with CATL93?

I have a UPS of 5KVa waiting my best used cells to do packages of 36V (32 cells 2P8S) packages,

If you’re replacing 18s lead-acid cells with LEV50, you need to measure the UPSs charging voltage to stay within safe limits, 8s (32.8V max) doesn’t seem enough.

 

[kiev]

I think a fuse in the Middle of string and this numbering are crazy

i agree it is weird and hard to understand, that is why i drew the layout diagram to help identify the cells.

Computer and controller software code doesn't care if something is crazy--it just does the routine task with no concern for human customs.

Tesla and Nissan Laef use numerical labels starting at the lowest voltage cell is #1 counting in sequence up to the top. Which is the convention of how the LTC BMS chip and most all other BMS chips that i have studied seem to follow.

 

[Juanjo Madrid]

Aleluya

¿Has pensado en sustituir el pack completo por CATL93?

Si está reemplazando celdas de plomo-ácido de 18 s con LEV50, debe medir el voltaje de carga del UPS para mantenerse dentro de límites seguros; 8 s (32,8 V máx.) no parece suficiente.

Hallelujah

Have you thought of replacing the complete pack with CATL93?

If you’re replacing 18s lead-acid cells with LEV50, you need to measure the UPSs charging voltage to stay within safe limits, 8s (32.8V max) doesn’t seem enough.

Hallelujah Mickey,
I return my pack to the car and first test it's Ok, not turtle when full load, only test it 10 km, not hills but look ok, the SOC are very low. Now charging I note the two LEV50N are low compared to others this when SOC is near to 100% many cells are in 4.1V and the 50 N are with 4,04V, I think this is because I equilibrate at low SOC and the bigger capacity of this cells delay the full SOC of them compare to others.

I think replace for full CATL if is necesary, with 60-70 Km Im happy, and the DIY work is hard, but look well. I buy also two CATL 93Ah but finally not put in my pack

I think 10S could be work for 36 V UPS, I read near to 40 V when charge.

 

[Jiminy]

I am in the middle of a stock cell swap on a friend's car and I would have made the same error in thinking that cell #88 was the last cell in the string and the most positive. Not sure what they were thinking.

I am shooting for an installed cell voltage of 4.01. Hopefully this will be high enough to avoid any large imbalance at full SOC due to new vs old cell quality.

 

[MickeyS70]

Now charging I note the two LEV50N are low compared to others this when SOC is near to 100% many cells are in 4.1V and the 50 N are with 4,04V, I think this is because I equilibrate at low SOC and the bigger capacity of this cells delay the full SOC of them compare to others.

I am shooting for an installed cell voltage of 4.01. Hopefully this will be high enough to avoid any large imbalance at full SOC due to new vs old cell quality.

It’s a given that you will see imbalance if you add (a) new or significantly higher capacity cell(s) to a pack, wouldn’t loose sleep over it as you know the reason why…

 

[Jiminy]

Sorry, I am using new-to-me used cells. Not mixing in brand new cells. I bought cells that I thought were a relative match for what was in there already. It is now seeming that the "new" ones might be significantly better than the 82K originals but I have only capacity checked the worst "old" cells thus far.