2001 HV Battery Dead. Could bad 12v battery be to blame?

With a bad 12V auxiliary battery there can be little confidence in anything the rest of the system is doing or not doing. The way to prevent the 12V from going bad while being parked for long periods is to install a battery minder, maybe a solar powered trickle charger if it's parked outside.

Still, it seems reasonable the HV battery may also be bad at this point. After running a good 12V battery you can view the charging and discharging of the HV to see if it is fluctuating quickly from one extreme to the other in short periods. Also, if the engine does not shut down when stopped that would be a sign of having to constantly charge.

For the value look it up in Kelly Blue Book considering the cosmetic condition and miles and subtract the cost of HV battery replacement once you have determined it is.

 

It sounds like you don't have a place to work on the car. Moving it across the street every other day suggests no garage or work area. This pretty well means you are limited to dealer or an independent mechanic. You might want to call these folks and see if they have anyone to recommend:
Auto Careers Development Center - Hybrid and Electric Vehicle Repair Training

An independent shop could handle installing a rebuilt traction battery, say from ReInVolt, for about $2,000-2,500. A failing traction battery tends to run hot. If you hear the traction battery fan running, it pretty well confirms their diagnosis.

Let me suggest reading the sticky on who should own one of these Prius. My thinking is this car needs to find a new home and you might look at the 'Prius c' as a replacement.

New, under warranty, you'll have a car with much improved technology. But given how little you use the car, you might look at non-hybrid, affordable cars. I don't say this lightly but even a Prius c is going to run about $20,000. You know your own situation better than me but an ordinary car might meet your needs and the lower MPG for small, annual miles, might be a better solution.

Older cars replace predictable loan payments and warranty with reduced reliability and unplanned maintenance. It can be a good solution for those who can do self-maintenance or at least diagnosis.

Bob Wilson

 

It is likely that the traction battery failed. Get rid of the Prius, and just rent a car once a month or whenever you need a vehicle.

 

You have two issues. One: the 12v battery, and Two: the traction battery with those two cells especially. If you are having difficulty finding the 12 volt battery, you can temporarily get a used regular car battery at most car garages, and with jumpers; hook both batteries together in parallel. Just like if you were doing a car jump started. Leave the battery in the trunk, and as long as you don't drive like a wild man, the regular 12 volt battery will not move around. Again, this is temporary, until you get the normal 12 volt battery for the Prius.
If you are on a budget and have some time on your hands, and you are somewhat mechanically and electrically inclined, you can take the traction battery out, removed the two bad celled, and replace them with good ones. You have to make sure they are the Gen I's, or make sure that you had not had work history already done on the car, and the battery pack already has Gen II batteries, or Gen III, which can happen as these Gen I Prius's.....Pria....hmmm? get older. There's a smattering of web sites, blogs, and YouTube videos to check out about the change out.
In fact I just changed mine out last night, but I bought a used, and somewhat unknown (although it was in a Prius about 12 months ago and ran fine and the owner kept the battery pack charged, and the voltages were good) my Prius would not start up at all, after the install. In fact that is why I'm here on the Prius chat right now, and saw your post and decided to post! LOL. I think I may have a bad ECU, the electronic control Unit inside the battery pack. I could swap it out with my old one.....maybe....but I digress! Good Luck!

 

NYC now has bikeshare, very cool.
NYC Launches Bike Share Program, Largest in Nation - ABC News
Sell the old Prius, ride a bike in town and rent a car for weekend trips.
As for valuation, tired looking Gen1's that need HV batteries are usually worth $500-$1500.

 

Electric bicycles have grown up too. They offer extended range yet light enough they can be stored in an apartment.

Bob Wilson

 

Unfortunately, they are illegal in NYC. Its a terrible rule caused by inconsiderate couriers.

 

Buy A battery pack and keep it handy, the boot sometimes locks out, altitude effects this mode as does the brakes pressuring whilst you try and start. I use my battery pack once a week and my mountains are more like mounds to your US hills.