Help! Dealer just said I need both batteries replaced...

I'd call around to some independent shops in your area and also search on Yelp for ones that may specialize in hybrids. They often have good sources to salvage yards to locate a used main battery for you for way less than a new one.

 

It sounds more like the inverter to me.

Jump starting is the number one cause of failed inverters.

I would replace the 12 volt battery and test the inverter before I spent any money on a new hybrid battery. The bad news is inverters are more expensive than batteries.

Not that it matters now, but if you have smart key, use the disable button next time you park it for a few days. That will keep from killing the 12 volt battery.

 

Here are some mail order sources for 12 volt batteries for the Prius.


Exide AGM Car Battery (Group S46B24R)

Optima DS46B24R Optima battery direct fit replacement for Prius 2004 + , Prius V & Plug-in Prius with Instructions

If you get the terminals wrong, even for a second, you will do several thousands of dollars of damage to the Inverter, which is why I recommend the little jump-start chargers instead of attaching to another car.



Should it turn out you need a different HV Battery, used starts at about $800 DIY to $1800 installed

2006 Toyota Prius Base 1.5L in Charging & Starting Systems | eBay

 

Have the 12V battery replaced first to confirm that the driveability symptoms (traction battery not charging and low power output) persist.

Ask your dealer's service writer for the DTC logged by your car. I would agree that the diagnosis of a failed traction battery appears to be reasonable given the symptoms you described.

Assuming that the traction battery needs to be replaced, you will need to find an independent mechanic who specializes in Toyota hybrids who can help you to install either a used battery from a salvage yard or a "remanufactured" battery which is one step above a used battery and has a one year or two year warranty. Good luck.

If the OP is able to jumpstart the car and the car will run, then the inverter is not at fault. If she had screwed up the jumpstart polarity, at minimum some fuses would pop which would cause the car not to become READY. So that is not a concern.

 

It sounds like an unusual string of problems given that there's no causal relationship between *any* of them. Perhaps this is a case of being sold a lemon, as in someone who knew that the car had a number of problems and just cleared the codes and patched things up etc to get it sold.

 

It appears that the OP had the following problems:

1. Weak 12V battery (this will happen especially if the car is not regularly driven. If the battery is original equipment it is ~7 years old and way past-due in being replaced.)
2. Front tire blew (not the fault of the Prius. This typically happens due to impact with road debris or severe underinflation causing damage to the tire)
3. AC went out (if the condenser was the problem part, that may be related to #2. If #2 occurred after hitting road debris, that debris may have also damaged the condenser. Otherwise, this would be a random failure associated with the car having logged 204K miles.)
4. Bad traction battery (after the car has logged 150K miles, there should be no surprise when the traction battery dies.)

The Prius is way past end-of-life at 204K miles and some amount of remedial repairs will be required from time to time.

 

I wonder if the inverter pump is failing - the overheated inverter would shut off power to the A/C to protect itself, and send the car into limp mode (no power, no HV charging), and show a bunch of scary warning lights.

 

Pat is right on when it comes to a 7 year old 12 volt auxiliary battery. But any 7 year old car with >204,000 miles can't be said to not be driven regularly. I mean jeez ...even if it were only driven every other day - that's over 160 miles round trip ... every week of every month of every year. That poor Prius has had the dog snot driven out of it

IMO, the best case scenario would be that a battery pack can be rebuilt out of used modules. Plus, some folks get rebuilt packs done for under $2k. - turning on how many bad modules there are in the bad pack. I would look into that myself. That's cheaper than buying a whole new car.
.

 

Cheaper alternative if it actually needs a new traction battery? Sorry but no, there really isn't one.

Make absolutely sure that the stealership isn't taking you for a ride. They will if you let them. Get a second opinion from an independent hybrid specialist in your area so you don't get ripped off.

So you bought it five months ago and it now has 204K miles on it? How many miles did you put on it in five months? Seems as though you bought it with nearly 200K. Depending on where the car was driven the last seven years (hot and hilly locations are traction battery killers) and the TLC or lack thereof it received, you took a BIG risk and may have lost out big too.

You have two options:

1) Replace the bad traction battery with a re-manufactured one for about $1500 installed (you aren't going to be able to DIY if your husband is deployed) and pray that's all it needed.

2) Sell it as is to someone who really wants a Prius (or another one ) who will replace the traction battery as they see fit. You might find someone (probably someone who already owns a Prius) willing to pay you $3K or more for it in its present condition.

Your best option IMHO is 2. To be blunt, this is beyond your ability to handle on your own unless you know someone who can help you while your husband's away.

Hope you didn't pay too much for it. It's always risky buying a used car, particularly a hybrid - especially one that's 7 years old with mucho miles on it.

Best of luck to you no matter what your ultimate decision is.

 

Be sure to keep us updated with your progress as the accumulated info is helpful for the knowledge base.

 

"My question is, how do I go about finding a used battery?"
Without knowing where you are (Country, State or Province) we can't recommend a nearby source.

Here are some.

Our Installers

 

I've seen used traction batteries go for $900 installed on my local craigslist if you're looking to save a buck and are unable to replace failed modules yourself.

 

There's a potential world of difference between a used pack and a rebuilt one. IMO, I would start to become leary when the price gets that low.

 

Agreed but a "rebuilt" pack most likely only had the bad module(s) replaced to which it is still a "used" pack and a warranty is only good as long as the re-builder is still in business.

 

I would get a second opinion to make sure the HV battery is indeed bad before spending time and money on a used one. Ask the dealer for the DTCs and post here.

I would follow Patrick's suggestion:

I would check the inverter coolant pump - look into the inverter coolant reservoir for fluid movement with the car in READY mode.

 

+1

A "dead HV battery" is usually a false sign of something else. Fix one thing at a time, and do the diagnostics as already explained above. The fact this all started after multiple dead 12v batteries and jump starts, makes me nervous.

 

Have you replaced the 12V battery yet Kristie?