Failing battery, inverter, both?

The thought had crossed my mind that the battery ecu may be causing the P3024, but I wasn't sure how to go about testing it. Could a bad or corroded sense wire cause a false bad block as well?

I will try out the charge discharge test once I get the inverter pump sorted.

Thanks for the feedback strawbrad.

 

Ok, that makes sense that it would be a new harness. I’ll probably go ahead and get a battery ecu off eBay while I’m at it. I’ll take a look at the old unit to see if there’s any visible damage.

I’m definitely going to give that thread a read, interesting stuff from the looks of it.

 

Replaced the inverter pump and it looks like flow is more or less the same. Sitting still after a short drive the inverter, mg1, and mg2 temps are sitting around 115f (46c) in 60f (15.5c) weather. When driving, temps are going up to 150f (65.5c) very quickly, but will come back down after 30 seconds or so.

I’m wondering if these temps sound reasonable, or if I may have an obstruction.

Edit: Scratch that, I went to try and bleed it again in case I missed some air, and it looks like it’s flowing pretty good now.

 

Here’s the new pumps flow, for anyone interested.

 

Got the new battery ecu installed, the original looks perfect, no corrosion or obviously burnt components on the board (not to say it couldn't still be malfunctioning).

I went ahead and did a battery test as described by the hybrid assistant app, and these are the resulting graphs. I started the test with 80% soc and the app lost connection, by the time I got it reconnected it was down to 75% soc so I hope the results are still usable. It was bouncing between 12 and 14 amps during the test.

I also logged a 90ish minute drive with torque, and the block deltas jump up kinda high, I'm not sure if that is normal during regular driving or not.

 

Ok, that makes sense, I can definitely see how that would cause high deltas. I guess it's time to start taking it out for longer drives now.

Fingers crossed!

 

Last week I was monitoring with the Dr Prius app and everything started lighting up yellow and red. It took me a minute to figure out what was going on, but it looks like all 14 blocks are charging as high as 19.5v during regen braking and sometimes when coasting. I haven’t been able to find if this is normal operation, I’m guessing not though.

I also did another discharge test a couple days ago, and I think block 14 is having trouble now. Is this looking bad enough to be throwing a code yet?

I spent most of the day today driving around trying to get it to throw the code again, but no luck yet. I found an empty road and accelerated to 50 and came to a firm stop several times, and it may have been my imagination but I thought I smelled burning electronics/plastics.

 

Aha, I'll definitely do that tomorrow!

After running the car around 600 miles trying to get it to throw a code I did another battery test, and comparing to the data I posted yesterday, I'm not sure what to think. Block 14's internal resistance has varied from 2 to 11 milliohms difference from the other blocks, and the max voltage delta has gone from 0.2v to 1.7v back to 0.7v.

I doubt it's the case, but could a loose bus bar nut cause fluctuation like this?

 

Ok, and here's a force charge. Everything seems to stay relatively close, unlike the discharge.

 

Here’s a final update to this thread.

tldr:dealer replaced the battery at no charge, and everything is fine.

In early July my Prius finally threw some codes for me (p0a80, p3000, and p3024), and I was finally able to get it to the dealer without clearing the codes. They confirmed the battery was faulty, replaced it, and gave me a loaner car for the couple days the repair would take. There was no charge for any of this, and the manager of the dealership confirmed for me that the new battery is warrantied for 3 years. It had been about 15 months since I originally had the battery replaced.

It’s been running great ever since. Next project is to figure out why when my gas gauge shows 1 pip left, I can almost never get more than 6ish gal in the tank without the pump kicking off.

Anyway, thanks again to everybody.

 

Honestly I don’t remember much of a change, but I’ll check what my temps are running when I get home a little later today.