P0AA6 w 526 and 612 : I don't think it's the battery - what next?

I left them in the rack because I'd read reports of swelling making the modules not fit back into the pack again. So was thinking leaving them in the rack would help mitigate that.

I'll get a fan on it ASAP and prop the bottom up to keep heat from building up underneath. Great advice.


Edited to add:
Desktop fan stolen from daughter and pointed at the pack now. hopefully this helps.

 

OHHH, OK good call, I'll pull the metal plate off the bottom as soon as this cycle completes.

 

well I just learned something interesting:

voltage is NOT capacity. Remember how my charger was not honoring my cutoff "voltage"? I had set cut off at 7500

I picked a cell and instead of 3 cycles, ran it 5 cycles. I also discharged it down to 6.0v instead of 6.3. Cells have been finishing at about 4500-5400 mAH after three cycles.

this one I cycled 3 times and when it finished the display read CUTOFF.

mAH was right at 7500l Voltage is about 8.6. So it DOES respect it, but it's not the voltage, it's the mAH it's monitoring. How it calculates that, no idea, but on every cycle it tracks the voltage and mAH.

So I picked three other cells and cycled them 5x at the same parameters. They are all finishing at about 8.6- 8.7v and about 6500'ish mAH. which was much better then 3 cycles and finishing about 4800-5500mAH.

Also pulled the catse as per priuscamper and have a fan on them now so they are still staying cool. I'm charging at 3.0A but discharging a little faster, at 2.5.

 

Update: Great success!

After a couple of weeks of charging, discharging, charging and tracking progress, I got so all but one of the cells was above 7000 mAH as reported by the charger. Most were between 7300-7500mAH.

Ironically it was one of the two replacement cells I ordered. I got two, one was from the recommended source, one was from Amazon. The Amazon one was dirty and looked like it had been outside for a month, it came right up to 7500 mAH in one cycle. The other replacement I couldn't get over 6400mAH after three cycles.

I ran out of time, daughter had to go back to school, so I took the cells and reversed half and hooked then together with solder wire. That didn't work, I wasn't getting reliable contact on several, so got normal stranded wire and hooked them up. Didn't have a lot of time. Hooked then up Friday at midnight, and got up at six to reassemble.

Pulled the modules, spot checked about ten, all same voltage, then paired the weakest and strongest into blocks.



I also tried to place the blocks that started the strongest in the middle of the pack, although that was harder given pairing strongest weakest.

I did look close at the bottom of the support tray and found this under cell 13. Here's the source of the issue




Got the cells back in the pack, reassembled pack and threw it in the car.

I started it and it immediately didn't go into drive. I panicked, almost cried, then remembered you can't just flick it over, your have to push down to get to drive.

Went immediately into drive and we took off. Drove it about ten miles, very nervous but threw no errors. And the car fell much much stronger and smoother than previously, but I thought it was just me.

Block data from torque during initial drive


Later my daughter moved it to pack her stuff into it and came in and not realizing I was standing there, told her mom it drove better than she'd ever felt it. It's quick and very smooth. I didn't mention that to her, she just noticed it.

Loaded up and headed for college, car made it 250 miles with not a hiccup. She mentioned it's driving much better, battery never drops to purple like it had been doing and she was very happy having the flying avocado back up and running


Thank you to everyone for the advice and help! So amazing what you guys know about these cars.

But the daughter is super happy, I didn't get cooked in the process, and the little Prius soldiers on..

 

What do you mean, the car or how happy the daughter was to have it back?

She really likes that thing, more than I realized

 

Let's hope it's closer to three years than three months lol..

I did show her how to clear codes. But with 190k on it, hard to know if throwing two K at it makes sense or if I just keep fixing the battery when it has issues

 

Lol, hahaha, nope you are right, just couldn't figure out how to use the blur tool at all.

She was just real happy to have her Prius back. She would check on is every day during the repair.