Balanced but weak pack looks good at 2 A discharger rate
Waynetc from Insight Central sent his pack to me via Ray Holan who was coming out for a charger harness and MIMA install.
Wayne had discharged the pack so we started with an 18 hour soak charge, and then discharged. I did not have the datalogger available as Ray was setting up a Database program for me to give me better order tracking and inventory control. (Thanks Ray)
The pack discharged down to the Minimum discharge voltage I had set up at 135V. Got 130 minutes of discharge.As we can see from the close up, and the slope graph not showing the charistic increase in discharge slope that we have seen before, so this pack probably could have been discharged to a lower voltage, the slope ending on the flat shows it still has more to go before depleted.
I recharged and set up the datalogger to capture the second cycle, which ran for 166 minutes of discharge. We can see from the nice reasonably flat discharge slope graph that the discharge proceeded at a reasonably nice rate of 25. Lower the number the better the pack can provide current under the ~2A load. Have seen 4-5 minimum slope on really good pack, and as high as 120 slope on the really bad silver pack with multiple cell drop offs.
Since 2 A is a low discharge compared to the cars 100A, we will need to do more testing to see how the 2A data reflects the higher currents in the car, when I get the 60A stick discharger ready.
Wayne reports that his car would only provide 2-3 seconds of assist and then it drops to 33 - 50% assist - this is with or without mima. He can do this over and over again, or hold the joystick forward and get very mild boost. Then after a while the assist gauge will go from 19 - 20 bars to about 3 and it starts to charge up again. That's when it pops codes - usually 1447 - 1149.
We will see what happens.
He will let the pack sit for a week while he does other work, and will do another discharge then, so he can get an idea of what the self discharge is like.
Will log the self discharge over the week.
We are looking at making an automatic stick by stick 60A discharge tester that would tie into the discharger jack.
A new mode 8 will be made (Code V2.3). The idea would be to open the pack. clip big alligator clips to the ends of each stick,one at a time.
A press of the start button,would do a test which would read the whole pack voltage, turn on the 60A load, wait a programmable delay, take another reading, then turn off the load. The difference between the two voltages will represent the high current discharge internal resistance of just that stick.
Run through the pack,write down the results and we will have an accurate stick by stick internal resistance value.
Lets see how Waynes pack works regarding self discharge as well as how it responds to the real world load of normal driving after he gets it back in the car, and may want to use his pack for the high current stick level test to help us better understand how to qualify the packs and the subpacks within it.