Jim, if you want definitive data to present in this graphic form might I suggest this?


If you can get it onto EV, roll out real easy and slowly accelerate until pulling over 60 amps from the HV battery. Keep the engine OFF! Then abruptly step into the accelerator pedal to about 30%. That will start the engine under stress.


You will see dramatic block divergences as the current abruptly goes from a near steady 60A to over 100A.


Any weak cells will drop near to 0.


A totally healthy pack should do this with a small voltage divergence.


From what I see here you may have over 50% damaged cells.

 

Simply attach the zipped CSV to a message here in this thread. You will need to "go advanced" and use the paper clip icon to attach a file.

 

NOTE: I forgot that Torque Pro exports the CSV already zipped, so you merely need to attach that zip file to a new message in this thread.

Background: 2 year old pack generated from the leftover "garbage" of 3 different packs. This pack does not meet any portion of my standard for what I'll install in a customer's car. It is entering its third Phoenix summer after about 35K miles. At the detail level, it shows significant deterioration (about 40% the rating of a new battery), yet it does not adversely impact mileage or other performance.

In short it is grossly imbalanced, suffering from severe loss of capacity and is as "unmatched/unbalanced" as a working battery can be.

This test was conducted this morning with the 3 pack temp sensors reporting a low of 111°F at the beginning of the test and 120 at the end of the test. Max deviation between the 3 temperature sensors at any given moment in time was about 5°F

The attached picture shows a brief but relatively high current discharge and charge.

You can see the SoC curve progress downward, kick down sharply and then increase during charge. The kick down is an indication of lost capacity that can be recovered through reconditioning.

The current is included to indicate phase of operation and magnitude of charge/discharge. (+) current is discharge, (-) current is charge.

The 04-09 Prius reports Min and max block voltages and corresponding block numbers (out of 14 blocks). I only log these as they minimize the data lag and usually tell me everything I need to know. The Max voltage minus the min voltage is represented as a single number and plotted against the right axis.

Even under high current (25A discharge and -80A charge), the min/max voltage deviation stays well under what you see in your low current plots. Yes, they are notably higher than the 0.2V mentioned, but that is because the battery is known to be grossly out of balance and deteriorated.

The deltaV increase towards the end is a result of the lower capacity cells filling much more rapidly than the higher capacity cells and causing a big voltage skew - again due to the known imbalance and capacity loss.

 

trying to
go advanced, could only find that if I search
feeling stumped.

 

I'm using Chrome on a PC. I don't know what you're using. At the bottom of the thread, I have a window in the "Quick Reply" field. Below that window, I have the "post quick reply" option or "go advanced" where I get a more full featured editor.

 

Trying to go advanced, lokking for an active paperclip. I am using my android.

 

Hmm... Limitation of the mobile browser. use your Browser menu to load the "desktop site". it will look like it does on a PC.

 

Thank you
I will get off my phone and use my PC for the upload.

 

here is some data finally.

 

I only looked at #1 so far. The current number is WAY off. Based on expected max/min currents, they may be off by exactly 20X (too big).

"Voltages" shows 20 blocks at start of log and and of log. They align horizontally, so that the voltage labels are the same for both.

Note at the left side, the voltages aren't great, but they're likely around 0.5V spread at the starting SoC of about 70%.

At the right side, the voltages vary by 2-3V consistently where SoC is around 50% - this is atrocious.

"SoC and dV" simply show the total voltage range and corresponding SoC vs. time. You see the same thing here. ~70% SoC = about 0.5V deviation; about 50% SoC = 2-3V deviation.

I'm not going to bother looking at the others. This confirms my assertion that your battery is destroyed. The only way you have even 20 good modules (Hillbilly's 50%) is if every single block has one good and one bad module. This has never occurred in my experience and wouldn't make any sense.

Given that your spread between the top two blocks is about 0.7V at the 50% SoC region, I would estimate that you have 2-3 GOOD modules out of 40. This is assuming the top block has two good modules and the next highest block has 1.

I've included the Excel file as a zip.

Good luck,

Steve