HV Traction Battery Failure and what else? (Torque screenshots)

Just looking for someone to look over my troubleshooting!

OBD2 scans
Torque + cheapo ELM327 OBD2 scan shows:
P0A1D U0293 P0A7F P0A80 P3015 U0100 U0111

El Cheapo ELM327:
U0293 u0100 u0111 u0293 p0a1d | PriusChat
covers nearly all of them. I got weird errors and check engine lights even during good times, driving with the OBD2.

Need a new HV Battery!
P3015 and P0A80 - looks like block 5 is bad.
Please see the pictures: block 5 voltage is low
Seems internal resistance R06 is missing from the Torque default PID set.

Are the battery temps too high?
44/82/84/82? As mentioned below the HV fan is blasting away.


Symptoms / backstory
Car went into limp mode while sitting at the drive through with the lights on. I pulled over, let it rest for a while as per recommended, had my burger, and made it home with no issue. I've been driving with a Christmas tree dashboard for a couple weeks now. (see attached).

The gas engine revving, because it's failing to charge the HV battery, watching the HV bars drop before my eyes on its own, the HV battery fan going at full blast in the back is new and concerning.

Usually get 40MPG, 45MPG on long highway drives for the last 40k miles.

I have seen one of the blocks at lower-than-others voltage before. Guess it caught up with me.

Recent maintenance
Dealer oil change and new 12V battery self-installed a few months ago.

Screenshots:

 

2006 Prius. 120k. Commute is quite short. Parked outdoors in SoCal.

Local Toyota is quoting $1657 + core for a new one. How difficult is the OEM-OEM battery swap?

 

Can anyone tell me what the hell this bolt is? It's a 12mm with a tapered bottom. It was placed with the bolts that mount the battery to the car (5 bolts total), but this bolt doesn't fit!!

It's a whole different color and the threads are kind of messed up.

My organization system has failed me (shakes head at self). I'm just going to run with 4 bolts on the battery if I can't figure this out.

Good news. I drove back to Toyota on the new battery (~25 mi round trip) for the core return and my car is zippier than before. Now to bolt everything back together without losing too many plastic clips and screws.

Figure 1. Side view of bolt.
Figure 2. comparison to battery mounting bolt

 

Well, everything's done. Appreciate the help and reassurance. Car is now in better shape than when I purchased it.

For a 15 y/o car at 120k miles, I wish I had asked for special warranty dispensation before embarking on the repair. I can make the case that it shouldn't have failed so early right? I have half-a-mind to call them anyway and see what they'll say. However it was likely they'd say no, and it was super interesting getting to learn about my car.

I think my failure mode was the 1 failing cell. The Torque Pro graphing function showed a severe drop of ~1.2V drop to about 14.8V during acceleration, compared to a working block. Then it would kick on the charger somehow and jump to 17V.

OEM battery choice
I'm really happy about the OEM battery choice. In some ways having a whole new aftermarket battery pack would've been so much easier, or not having to swap the electronics bay. After seeing the corrosion, physical damage to even the working blocks over the last 15 years, replacing only one cell is incomprehensible, especially knowing about balancing problems. The heat had warped the plastic housing and there are areas of the bus bars that were completely blue. There was dirt everywhere thanks to the nonfiltered fan.

Addressing this kind of damage then torquing down each bolt is absolutely not worth it. Replacing many cells might have been ok in retrospect, but I'm glad I didn't have to crack the compression block open. Even though I can probably handle this much faster next time, I am happy to let Toyota build up a smart grid my old cells. I have purchased one of their new OEM batteries, and in doing so, purchased peace of mind.

Safety
If I have one takeaway about the process, it would be safety - learning about the battery, and going slow to remain safe. As mentioned in another thread, $300 would be very inexpensive for every weeknight's and a weekend's worth of work, going really slow. Not to mention the hazard of working on something dangerous like this. (Unfortunately my quote was much higher).

Saw a video of the 10-min-interior & parts strip with a barehanded guy. Looks like that guy's done it 100 times and he makes it look disarmingly easy. Do not be complacent. This was beyond the limit of my skills and I needed to ask the pros here for help. For the rest of us, it only takes one faulty battery, one slip of the wrist before someone becomes a statistic.

Wear long sleeve shirts, jeans, closed-toed shoes, and the safety gloves when you're near the HV. Obey the one-hand rule. Wear latex gloves when remotely close. There are so many sharp edges. I have a scratch from each day I worked on the car, on a different part of the body. I was not nearly as careful as I should've been, and I was trying to be careful.

Learn the principle of operation and how the battery is 100% disconnected by the safety plug in the service manual (found in another thread here). Do not trust anything, especially quotes that put you at ease. "The voltage is cut in half, rendering it safe" is a quote I read here. I can see how they arrived at this conclusion with the safety plug about 5 blocks in, but it's not correct. Even with the safety plug removed, assume it's fully charged at all times until you measure it, and even after that. Until you become comfortable working around the battery that it's not charged, use the gloves.

Other
That said, does anybody here want a set of size 8 electrical gloves? =) I have the outside liner too. I have small-ish hands and these gloves barely fit; check out the sizing chart at Magid. Use a tape measure below your knuckles, wrapping around your hand. This will only fit if you measure 8" circumference.

That bolt presented no problem once you steered me the right direction; thanks @ericbecky. That's incredible you were able to determine details from poor-quality photos @ChapmanF and if I may be honest - so, so much more than I ever needed to know - but you knew that of course =)

 

Ok, I called local Toyota parts & service and Toyota HQ, and I cannot qualify for a special dispensation especially for an after-the-fact repair. I asked for partial or full reimbursement.

So the only option I have left is to open a dispute resolution as stated on pages 7-8 here:
https://www.toyota.com/content/ebrochure/warranty/2020/T-MMS-20RAV4HV.pdf
I'm not sure I want to do that. It was time (15 years) for replacement anyway, even at 120k miles.

Tips for others:

• At least show your Toyota service advisor the problem so they can document it. Inquire about warranty before you buy anything.
• Monitor your HV battery regularly with an OBD2 reader that doesn't throw false codes. If one cell looks weak, baby it. Don't let it go through cold/hot cycles. Drive it for 5-10 miles every day or two, which I failed to do during the current epidemic.
• From a price perspective, if you're going OEM, you may want to consider an HV battery replacement sooner rather than later. The parts dept manager let me know that they're trying to reduce inventory - sounded like nationally, but at least regionally or statewide - which may explain the lower prices. And people all over the site say that current prices are amazing. Things may not stay this way.
• After replacing the 12V battery, it seems battery prices in general are through the roof. I suspect there may be current trade tensions that make imported Japanese Toyota OEM battery prices look quite good. It cannot be cheap for PrimEarth to refurbish/manufacture/ship Gen2 Prius batteries. I guess it's demand-based. You probably don't want to be on the tail end of that demand curve, when prices may go back up.

BTW, I just read another chat that showed block 5 is bad. What is it about block 5?

 

Seems to have a bit more power accelerating from stoplights. Other than that, nothing noteworthy except that my HV fan isn't blasting like a jet engine and the car hasn't entered limp mode (knock on wood).

Generally haven't driven enough to know. About 35-40 mpg on the few local miles I've driven with my lead foot. About the same.

 

The bolt was a tiny bit more difficult than others but was no match for my shade tree skills

 

You got it! Our good friend Eric says:

It is a mounting bolt and belongs in a specific location of the battery case.

Driver side of car.
The hole toward the front of the car
It is quite snug when inserting, but it does fit.

Although on yours, it does look like someone messed up the threads.

It drives me crazy when these are not put back in the correct place. It also tips me off that someone has been messing around in the battery area.​

 

Yes, correct, that's where it goes

 

I have a harebrained theory about why block 5 for everyone fails. It's where the safety plug is located. The cell needs to work harder than the other cells to push the electrons past the safety plug especially given corrosion. I've heard of block 6 failing a lot too, but not block 4 for some reason.

I'd expect block 4 to fail since the electrons move from negative to positive and the resistance is at 5. Perhaps the resistance is actually what's saving cell 4, keeping it cool. Block 6 will suffer higher "inrush" charge current after the electrons make their way past block 5, developing higher heating.

If this is correct, battery block rotation should help. Any rotation at all is better than none, but given the aforementioned hypothesis about block-to-block effects, better to rotate by more than one block while you're at it anyway. I'm thinking since block 5 is 1/3 of the way up the pack, it may be easiest just to rotate the blocks by 1/3 and for symmetrical purposes. Since we're doing thirds, and a standard battery pack's 8-15 year battery life, rotation should be done every 3-5 years, and perhaps this could help length the battery's life by 3x?

I monitor the Prius subreddit and feels like 75% of failures includes block 5 or 6.