Replaced bad HV module. Left with P3024.

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Finding the questionable modules is best done under load, or by letting the pack sit for many days, the weak modules will start to voltage sag a bit faster when compared to the rest of the pack.

Given that you only had a P0A80 to work with, not a bad call at all.

Rebalancing is always best, especially at your mileage or when swapping modules.

Prior to the P0A80 and this repair, did you notice any of the telltale signs of battery degradation?

Sounds like you've found another bad module, have you measured the voltages for that block already?

Was the HV battery fan cleaned recently?

Did you clean up the wiring harness and bus bars during the swap?

Could be worth the investment, and should last quite some time.

Could get expensive quickly if buying online individually. Might look for a decent pack at a local junk yard

This sounds like the most bang for the buck, especially since you've removed the pack and are familiar with the process.

Doesn't sound you did anything wrong, beyond the stated. Quite possible that was the cause though.

If the P3024 was the end module closest to the reversed compression plate, that could be one answer for the current P3024. Both end modules will swell on the side closest to the plates (opposite ends of the pack), as the plastic plate doesn't offer much physical resistance. Reversing the plate gave the module even more room to bloat, and fail.

Personally, I would just swap another decent module into the mix. But your spare time situation might be different now.

Pinging @PriusCamper who is always helpful and has a wealth of knowledge on the local available battery options (junk yards, rebuilt packs, etc). And if not already in use, has the proper balancing gear nearby to you..

 

HI Jake, I'm an hour south of you in Olympia... Congratulations on getting this far... Even that much is a challenge... You succeeded in finding the bad module, just not finding the next module to go bad. You're getting close to it being fixed though. And if you can clear the codes and get some miles on the pack, things might settle down for a while.

There's several way to find bad modules before they go bad. Creating a spread sheet of all numbers from load testing is key... Also if you recondition individual modules simultaneously by discharging the same way you do load testing you can watch the voltage drop and a module soon to go bad will lose all it's voltage before the other modules.

Also charging and balancing with a Prolong charger is a great way to wrap up the work once the pack is back in the car... Anyways, let me know how I can help? Currently all my loaner packs are out right now, but if I get one back maybe I could help you out.

Or if you've had enough, there's a Seattle Toyota dealer selling a replacement pack for $1650 and takes a couple hours to install....

 

Jake,

The DTC P3024 is actually "battery block 14 becomes weak". Block 14 is the 2 modules closest to the ECU end. The ECU is merely looking for a certain voltage difference between the highest block voltage and lowest block voltage. Once it sees that threshold is exceeded, it triggers the P0A80 code. It doesn't necessarily mean you have a "bad" module, just that you have exceeded the threshold between strongest and weakest. If the module you previously installed was a "superman" module, it may be causing its block to read very high, which would make it that much easier for the "weakest" block to trigger the threshold. This is why it's more important to have 28 well balanced modules than 27 decent modules and one great module. That great module will screw you, since it may make even a decent module trigger the code. The absolute worst thing you could do for a OEM Gen 2 HV battery would be to install a single brand new module. You need one that's matched to the average of the other 27. Newer/higher capacity is not actually better.

The P0A80 code will illuminate the RTOD but still allow you to go ready and drive the car normally. Any individual block code (like P3014) will allow you to drive the car, but only in fail-safe mode.

The plastic end caps and steel tubes are designed so that when properly assembled, all you need to do is tighten the 8 fastener bolts and they'll pull tight on the tubes providing the correct clamp force on the modules. If you install one backwards, all you'll see is that some threads on the fasteners are still exposed. The worse that would happen is that they clamp even tighter, unless you left it loose in order the get the end caps to fit on the floor plate studs.

 

Well, at the very least, you're going to want to charge or discharge each module so they all have roughly the same voltage before you put it back in the car..

And then to do reconditioning of individual modules you're going to need to charge the modules up with NiMH rc hobby chargers. You're also gonna want to watch multiple voltmeters reading voltage as the modules discharge so you can compare how fast or slow. Of course before you get to that you're going to need to build a spreadsheet and load test the modules. Did you find the load test instructions yet?

Your main challenge is gathering up all the equipment... Enclosed is a photo of what a system that's going to not take an eternity to do all this work. It can discharge 5 modules and charge 5 modules at the same time. I hope to upgrade to a new system soon tha tcan do more than that. My buddy in Oregon can do as many as 80 modules at once with lab-grade equipment, but that costs tens of thousands.

Buying a Prolong Charger used can be had for $200 in rare circumstances, but I've only seen that a few times. In general they're expensive and there's few easy ways around the $150 wiring harness, which has a box that controls fan speed that can't be replicated on the cheap.

Another way to look at it if you're planning to sell the car at 150K and are interested in your next car being a 2015 or earlier Prius, you could buy a pack that doesn't require a core return/deposit like one of these: http://newpriusbatteries.com/ and plan to use that pack in your next car and take your time rebuilding failed pack and put it back in when you're ready to sell.

Or alternatively, buy a new pack at Toyota dealer, ditch your old pack with them to get your core deposit covered, then buy a newer used Prius when your current one hits 150K and put the pack from that newer used Prius in the one you're going to sell, then put your brand new pack in your new used Prius and have no worries for a long time.

 

I got started with just two chargers and it was much slower compared to five...

The chargers are the SKYRC IMAX B6AC V2 for about $50 each... The free multi testers with coupon at Harbor Freight were a fail. So I bought those black ones on Ebay for about $5 each... The light bubs area cheap ($2) 12v 50w and 12v 20w to get most of the charge out of the pack and then the 10W discharge resisters for final stage of three successively deeper rounds of discharge. Hybrid Automotive has good discharge numbers in their online owners' manuals.

When I upgrade I'm switching to these chargers: HTRC T240 DUO Touch Screen Dual Channel RC car lipo battery Balance Charger

 

Yes... But given the labor involved buying just any old spare module online will be problematic. I did that once and got 3 miles out of the module I bought before it failed. Finding a good person to buy healthy modules from is essential. And in general those modules I buy are healthier than the pack, because they've been reconditioned. So I match the pack to the module by reconditioning it.