P0A80 :(

Time for a new HV Pack! I may consider rebuilding this one, got to get it out and see what happened, this was VERY sudden and initiated by going over an unusually bumpy RR crossing. Cleared the codes, but P0a80 was pending the moment the modules rebooted and with the engine running, the battery fan is on full blast and the discharge air is HOT!

Something MAJOR happened to the HV battery at 188k, but we knew this was possible and have budgeted for it

 

I certainly *can* and will remove the pack for inspection, but getting that hot combined with the sudden nature of the failure suggests to me that obtaining a rebuilt pack from a known source would be the best option.

We will see.

 

I promise, that thought is high on the option list

 

Update for the weekend....

After multiple charge & recharge cycles, I got two of the three troublesome modules to play nice, only one is still under voltage and by 0.8v OC and 1.2v Loaded, that suggests one cell of the 6 in that module is DOA.

In module order (closest to controller/connections = #1)

Initial / Post eq loaded @ 1.5A
7.66 / 7.63
7.71 / 7.71
7.69 / 7.64
7.69 / 7.64
7.68 / 7.65
6.84 / 6.55
7.69 / 7.71
7.69 / 7.74
7.69 / 7.67
7.70 / 7.57
7.69 / 7.64
7.71 / 7.71
7.67 / 7.68
7.70 / 7.74
7.70 / 7.71
7.67 / 7.71
7.69 / 7.71
7.71 / 7.74
7.69 / 7.75
7.71 / 7.73
7.47 / 7.75
7.71 / 7.74
8.24 / 7.68
7.70 / 7.77
7.71 / 7.68
7.71 / 7.75
7.71 / 7.68
7.65 / 7.67

As we can see, module #6 did not really recover at all, but #21 and #23 normalized nicely. This matches the documented experience of the Prius community, that suggests that ONE module kills the pack and often it is just one cell in that module.

Every module is original to this car, given it has been in the Dallas area since new and the failure was not in the middle of the pack, that is not what I would have expected.

Now to find ONE module of similar capacity and age to the other 27.

 

Back to like-new performance! One new-to-me module to replace the failed #6 and we are all good

No damage or other physical appearance of the failure, just a shorted cell in the module based on the sudden failure, mode and high discharge temperatures.

 

It *just* died as you suggested it might. Installed the "spare" extra module I had and it was cracked, so no good. When you charge it, there is a hissing noise = no good. Time to troll CL for another module.

BTW, this car sat for nearly 4 months in the Texas heat and then for another 3 after we moved back to MN. As we all know, HV packs do NOT like sitting unused. Also found the 12v DOA, with an OCV of 12.2v

This means that I will have spent like $500 on this car over the years in repairs, half of that is *just* in the 12v battery

 

Photo of the failed (cracked) module, bubbling away

 

That IS the one that failed this year and the photo is of it's failed replacement. I installed the second module I purchased last year to replace the now-failed #23 and it was no good right out of the box.

Now I have two module cores (cannot find the third anywhere ) and one good used one as a spare

 

No, 12 months later. It was totally fine until about two weeks ago, then I got the tell-tale warning lamps and yo-yo battery behavior.