I’ve got my hands on a 2001 Prius that a coworker had sitting for 2+ years after the cat was stolen. I’m trying to recharge/recondition the HV battery with a CQ3 hobby charger and so far it has been going well. Modules 1-22 bounced back beautifully with 5000+mAh discharges and holding steady at ~8v but 23-38 are all reading under 1v at the module. Can these be recharged/reconditioned or should I just replace them?
I think the only way is to try and see. I would charge up to 7.2 V at 325 mA, rest it for 5 - 10 mins, then do your regular charging regime. It will either work or it won't. You haven't lost anything trying.
<bump> congrats on revitalizing your traction (HV) battery. Happy new year (2026)... Come spring, I suggest you again pull the HV battery and clean all the grotty stuff off the contacts to the battery harness. When you have the sense side taken apart, pull the plug where the sense harness goes into the battery control module and clean up (as best you can) all the pins on the battery control computer orange connector to the battery. This part (82165-47030) is NO LONGER AVAILABLE in the Toyota parts system, so plan on taking extremely good care of the one functioning sense harness that you currently have.
