Hello,
The car is a Toyota Prius /NHW20/2009 year with warning lights in dashboard.Using a scanner I see in HV Battery ECU P0A80-Replace Hybrid Battery pack.
Then I looked at the freeze frame for this fault code.
Using this I found block 5 and 8 faulty(the voltage drop too much in the discharging phase).The HV battery use 28 cells(7,2v each,6 elements in one cell),in diagnose you will see 14 blocks(2 cells in 1 block)
Now is the time to find the faulty cell.Both cells were taken from the same HV battery(block 05),so the discharging rate must be the same. I placed in series this two cells and a 21w/12v bulb- the discharging process was captured with the scope:
the voltage from a good cell on channel A,
the voltage from a bad cell on channel B,
the discharging current on channel C
At the minute 15 you can see a drop of cell voltage(only at the bad cell) so the bad cell was discovered.
The voltage drop is easy to see,the current drop not.
How can be used this infos to calculate the cell capacity(a new one must have 6,5Ah)?Will be needed more datas?Just tell me what you need ...
Best regards.
Hello again,
Today I made a full discharge,do not try this at home!
Here you can see how the different 1.2V cells fails in the discharging phase...
here is the bad cell
Dear Victor,
this is a really new topic test by pico. Can i ask more about this?
is it mean the bad cell will drop the voltage like a step earily than good cell?
how to get the Ah in the math channel?
look forward to your answers, thanks.
Hello Victor!
I just see your post.
Please tell me !
I see that you use 4 x 10 ohms resistor on that PCB as load for that cell. Did you use them in parallel mode 2.5 ohms for this test?
Good job!
Hello Victor!
I just see your post.
Please tell me !
I see that you use 4 x 10 ohms resistor on that PCB as load for that cell. Did you use them in parallel mode 2.5 ohms for this test?
Good job!
Hello,
My module use 2 series resistors for 0,4A discharge current in parallel with two others(the last two can be switched off in the final stage of discharge in order to prevent the cell damage-the deep discharge at high current will overheat and deform the cell).
Best regards