JDD
Posts: 1
Joined: Mon Jan 11, 2021 10:59 am

Re: Problem with turtle icon

Tue Jan 12, 2021 8:18 pm

I am having a very similar problem on my 2012 MIEV.

Basically, when driving at highway speeds above 60 MPH the turtle shows up during acceleration. Using CANION, I have determined that turtle turns on when pack voltage drops to around 270 volts, which I understand is ~3 volts per cell (assuming 88 cells - is that how many this pack has?). While turtle is illuminated the car will regulate the power as low as it needs to in order to keep the pack voltage above ~270V.

Also, there does not seem to be a bad cell per se. When at rest, the cell voltage difference is 0.010 Volts. When under load with the turtle illuminated, the difference is closer to 0.4 Volt, with about 10 different cells at the low end and maybe 5 at the high end. Pack temperature seems fine at under 10 degrees C. I'm in Columbus Ohio, so outdoor temps were around 25*F when I got the data a couple of days ago. Last year this problem only occurred when outdoor temps were around 0*F. Now I can get it to happen up to around 35*F.

I'm starting to wonder if this is a pack age problem causing all the cells to have higher internal resistance than when they were new.

kiev
Posts: 1405
Joined: Sun May 03, 2015 7:15 am
Location: The Heart o' Dixie
Contact: Website

Re: Problem with turtle icon

Tue Jan 12, 2021 9:46 pm

That's a great observation, thanks for sharing. And great first post.

i have a car with a weak cell that will go to turtle under acceleration, but never made the connection to the 270V level for the pack, i was just watching the one bad cell.
kiev = kenny's innovative electric vehicle

bezzeb
Posts: 15
Joined: Thu Sep 17, 2020 5:53 am

Re: Problem with turtle icon

Fri Jan 15, 2021 2:00 pm

kiev wrote:
bezzeb wrote:...
After a series of tests I found the following problems
1)the turtle turns on only after the arrow goes beyond the border of the eco mode
if you release the gas and the arrow is again in the eco range, then the turtle disappears


By your data and images it appears to be a normal pack, but something strange is happening when the pack is loaded with a current drain above 50 Amps (the upper edge of the ECO range).

The Canion App allows nearly instant real-time dynamic graphical display of cell and pack voltage and pack current, so a defective or weak cell would show up with the high load condition. It is only under high load that the weak cell is unable to sustain its voltage, so it is not visible to the somewhat static display of the Lexia device. That's my guess..?

tested the cells while driving today and not found big discrepancy

at the same time, when fully discharged, the canion show low cells
Image

Image

kiev
Posts: 1405
Joined: Sun May 03, 2015 7:15 am
Location: The Heart o' Dixie
Contact: Website

Re: Problem with turtle icon

Fri Jan 15, 2021 5:14 pm

bezzeb wrote:...
tested the cells while driving today and not found big discrepancy

at the same time, when fully discharged, the canion show low cells
Image


Good job you have found the culprit--cells #12, 23 and 27 are worn out and can't keep up with the others. Plus there are 12-14 other cells that are weak and not keeping up either although not as severe. The normal difference between the high and low cell would be 10 to 20mV, but these 3 cells are out of family by almost 500mV.

The temperature data looks normal to me--nothing out of family or indicating an issue there.

You will need to either replace the pack with one in better condition, or drop it out and replace all the weak cells. The price for a new pack might be too much to invest unless the car is in good condition to last another 7-8 years. A used pack or used cells doesn't seem practical for long term, but might be a short term bandaid on the problem. Good luck, let us know what you decide.
kiev = kenny's innovative electric vehicle

bezzeb
Posts: 15
Joined: Thu Sep 17, 2020 5:53 am

Re: Problem with turtle icon

Sun Jan 17, 2021 10:37 am

kiev wrote:
bezzeb wrote:...
tested the cells while driving today and not found big discrepancy

at the same time, when fully discharged, the canion show low cells
Image


Good job you have found the culprit--cells #12, 23 and 27 are worn out and can't keep up with the others. Plus there are 12-14 other cells that are weak and not keeping up either although not as severe. The normal difference between the high and low cell would be 10 to 20mV, but these 3 cells are out of family by almost 500mV.

The temperature data looks normal to me--nothing out of family or indicating an issue there.

You will need to either replace the pack with one in better condition, or drop it out and replace all the weak cells. The price for a new pack might be too much to invest unless the car is in good condition to last another 7-8 years. A used pack or used cells doesn't seem practical for long term, but might be a short term bandaid on the problem. Good luck, let us know what you decide.

Thank you.
I have replacement batteries

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