'06 with P0A80 code. Replace traction battery with new OEM, or ___?

Hi All,

I have an '06 with about 135,000 miles that recently gave my wife the red triangle of death, VSC, and check engine lights. I hooked up my bluetooth OBD2 reader, and codes P3000 and P0A80 were stored. I cleared the codes, and P0A80 returned. While I was doing this, the car was sitting in park, ignition on, with no climate control, and I was watching the battery level display on the MFD go from 4 bars (blue) down to 2 bars (purple) in about a minute. The engine would kick on, battery would charge back up, engine would shut off, and the process would repeat every couple of minutes. MPG has been great recently, though there have been a few times over the past couple months where the traction battery loses all charge overnight.

Based on the codes, this behavior, and its age, I'm fully expecting the traciton battery needs replacing. I'm the 2nd owner after my mom, so I know the pack is original. I've got some hope that it might be corroded contacts, since it lived most of its life in a "marine" environment (less than a 1/4 mile from the ocean) and I've already dealt with lots of rusted/seized fasteners. I'll probably open it up to take a look tomorrow, but I'd like to start exploring my options for replacement now. I'm pretty darn mechanically inclined, and not scared of working on high voltage, so doing cell/module replacement/reconditioning is certainly an option, though I'd have to procure the proper equipment. It's our 2nd car, and none of us use cars for commuting to work/school, so this can certainly become a project vehicle. Are there options out there to convert the 2nd gen to a plug-in hybrid? Or new battery chemistries that will improve the fuel economy?

 

Thanks for all the replies so far. I downloaded Dr Prius and found that my battery block 5 looked bad - its voltage would drop well below the others when discharging, and surge above them when charging. I also got a new code, P0315 "Battery Block 5 Becomes Weak." I found a local guy who sold me two "reconditioned" modules for $30 each. I didn't ask about his reconditioning process, but at that price I was willing to roll the dice. I opened the pack, found one module more than 1 volt lower than the rest, and swapped it out. I linked the modules in parallel to balance for 24 hrs, shuffled the modules and reassembled the pack. Unfortunately, I still got the P0A80/P3000 codes; it looks like the module I bought is the culprit. But I found a potentialy bigger problem: the HV battery fan wasn't working. There was a ton of corrosion on one of the pins in this wiring harness:

On my 45 minute test drive, I saw battery temps get up to 138F, but I never heard the fan. OBDlink app showed the fan speed was 6, but the van voltage was 0. I clipped the brown wire and jumped it across the connector, and now my fan appears to be working properly. But over the past couple days, I'm still seeing pretty high battery temps, like ~115F when the outside temp is 70F.

I'm thinking the fan might have been busted for a long time, and repeated exposure to high temps has probably damaged all the modules to some degree. Does that make sense?

So, I'm looking into whole pack replacement options now. I called my local Toyota dealer, and to just buy the HV batteryfrom the parts desk will be about $3k with tax. My wife is leaving on a van trip through Oregon on Wednesday, so she could possibly buy from a dealer up there to avoid sales tax, if I can pull the pack in time to send it with her for the core refund. I'm just not sure exactly which parts I'd need to keep...

I've ruled out Project Lithium/NexPower based on the warnings about the "signal soother" and lack of a proper BMS I've read about/seen here and on Reddit/Youtube. Similarly, NewPriusBatteries doesn't seem like a great option, as it's $1900 and a fair bit of DIY assembly for a lifespan of about 5 years. I've found a couple options in the Bay Area for whole pack replacement that would take a couple hours to drive to. First is battery4hybrid, which can install a "BRAND NEW Battery" for $1999 at their shop in San Francisco or come to me for an additional charge. 5 year warranty. It's not clear from the website if "BRAND NEW Battery" means Toyota OEM. I'll call tomorrow to inquire.

Second option is greentecauto, who will sell me a pack "with BRAND NEW CELLS" for $1950, though I'd have to pay an extra $200 for residential delivery, plus the cost to ship back my old pack to get the core charge refunded. I expect I could pick up (and return the core) at their shop in Hayward, and they also do installation at their shop, or mobile installation, for a charge. 4 year warranty.

Anyone have experience with either of these companies? Both battery4hybrid and greentecauto have lower-priced rebuilt/remanufactured pack options with shorter warranties, but I'm not too interested in those.