Gen I HV battery (bad cell) repair/replace options?

My Gen I Prius gave me the red triangle of death and the "check engine" light. I could still drive it, but those warnings are intimidating, so I had it towed to the dealer, who informed me that:

• 
  
  • the HV battery has a bad cell and needs replacing, ($ 3400 incl labor)
  • the aux battery is weak, ($276)
  • the battery ECU may need replacing ($1500)
  Both environmentally and financially it doesn't seem right to have to replace the entire HV due to a single bad cell (#7). I've seen reference to a procedure from Jim Gatzke of Toyota's National Alternative Fuel Vehicle Service and Support group by which HV batteries can be reconditioned by replacing the bad cell(s) by ones with similar chemistry, but the dealer knows nothing of that. Does that exist?
  
  In San Francisco a hybrid-specialty garage (Luscious Garage) sells & installs replacement Gen I HV batteries composed of Gen II cells.If I have to replace the entire HV battery, I'd rather get newer battery technology. But I'm a non-auto-savvy non-DIY person, so I don't know what I absolutely need to have the dealership do before I take the Prius on the road again. (When the red triangle came on, car had only hesitated on accelerating a few times, but other than that it drove just fine. But the dealership claims that if I don't do all the work above, the car is likely to just stop suddenly. I am skeptical.).
  
  So here are my questions:
  
  1. Could a Toyota dealership recondition the HV battery, or will they only replace, even if only one cell is bad?
  2. Should I try to replace my aux battery by the Optima deep-discharge battery I see advertised (on elearnaid.com)?
  3. Is the Luscious Garage's gen-II-cell HV battery a good idea?
  4. What's the minimum the dealership would need to do to get me back to driving while I figure out the "right" solutions for each of the batteries?
  thanks,
  InfoHound2001
  -----------
  2001 Prius (147K miles, 10.7 yrs old)
  2004 Prius ( 97K miles, converted to a plug-in, driven by DH)

 

I am very glad to hear that Luscious Garage is a good outfit. I liked what they have to say on their website, and a recommendation from folks here means a lot. So now to figure out if I need a new battery urgently or not. (Their P3006 diagnostics show the aux battery voltage as 13.750, if that means anything).

As far as what repairs I need immediately, I guess I wasn't clear in my original post. By

"[minimum] I need to have the dealership do before I take the Prius on the road"​

I didn't mean as a permanent fix, I meant

"what's the minimum I need fixed in the dealership, to enable me to drive the 40-50 miles to Luscious Garage, in order to get them to put in non-OE equipment, both the HV rebuild and a 12V battery that's better than the OE?"​

Since I moved about a year ago, I had not found a good independent shop that's experienced with Prii, so I'd begun taking my car to the dealership again. At this point I do wish my car were at an independent shop so that I wouldn't be limited to OE solutions. And, ideally, to enable a nuanced conversation about LG's rebuild vs. ReInVent's batteries, as well as about what repair (if any) are needed in order to enable me to go 50 miles or so to LG. So that's also what I'm hoping to learn from this forum.

InfoHound

PS. This morning I also called the Toyota Customer Experience Center, to see if there is an alternative to getting an entire new HV battery pack. A: Toyota only sells new HV batteries, but given the extensive nature of proposed repairs he bumped my query to a Case Manager who "has more options". Don't know whether that will accomplish anything useful, or simply keep me in a rental car longer. (I am bummed that the HV problem didn't show up 9 months ago when it would've been covered by the California 10 yr/150K miles HW warranty. But if I have to pay for a replacement, I'd much rather get a rebuild with Gen II cell technology!)

 

Thanks Jeff. That is very useful, clear information.

But now that I know it's feasible, I'm having trouble making up my mind what to do:

I talked to Luscious Garage and they are a bit less enthusiastic about the rebuilt battery packs as they've now seen a few Gen2 cell failures in the rebuilts. With that info, and given the hassle of going to San Francisco, DH was pushing to just go for Toyota's new HV battery, (to get the 8/100K warranty again -- but it isn't; the replacement would only have a 12 month warranty).

The dealership says they can't test the ECU via a jumper aux battery or 12V source, to see if the 47030A ECU error code goes away, but they're concerned that the bad block caused a voltage spike and the ECU had gotten fried (the bad block voltage measured 14.08 V while the others are around 15.2 (~15.13 for the adjacent blocks, 15.4 for the outer blocks). So they have to replace the aux battery, the HV battery and only then can they check the ECU. Does that make sense?

Before signing up to spend $4,000-5,000, I would also like to evaluate the health of other main systems in this 11 yo car, to see if I'm likely to be spending more $$$ any time soon. What are the other big-ticket "problem spots" we should get checked out by the dealer or another? The transmission / inverter? HVAC system? Are there early warning symptoms to check for?

Thanks again. I love my teal Prius -- (though a bit less so now that I don't have a carpool sticker) but it is an 11 yo car with 150K miles, so I don't know if I really spend more in repairs than the Kelly blue book value.