bad main battery

I am big proponent for new OEM Toyota batteries but in your specific case if you already have a 2017-2018 Toyota battery with a bad module it might be a good idea to try and repair the existing battery. There are good chances that the rebuild battery will last for 5 years since it has 2017-2018 modules.

 

If it was a new Toyota pack maybe it is still within warranty? You should be able to find this by running the VIN through Toyota's site.

 

how many miles on her?

keep in mind, there may be other expensive problems over the next 5 years.

i would go with the new battery too. it doesn't sound like your mech knows what he is doing. you don't just 'replace a cell' for a successful long term outcome.
the 2016 sounds good, but what if it isn't?

 

"He was told that the battery pack had recently been replaced by Toyota recently"

Someone paid a dealership for several thousand dollars of parts and labor and did not have a receipt?

You pull off the pack cover you can see the codes on the cells and figure out of that really happened

 

Well how much would it cost you to get a second opinion at another hybrid mechanic? Have them verify how hold the battery is in your car now, and possibly read the problem codes on the car to make sure it's reporting a battery replacement code.

I'm not sure I can have much faith/trust in a mechanic that sold me a car with a "new battery" and then to have it die 2 years later. Then as a goodwill, charge me ONLY $1800 for another new battery. Seems like this is a bit sketchy from the beginning.

 

I’d take it to a Toyota dealer and ask them to diagnose. May cost you $75 for half hour’s work. They should also be able to track supposed Toyota battery replacement work. You may too on Toyota owner service history website.

Maybe that dealer didn’t use a new battery.

May still be under warranty and if not contact Toyota customer service. Seems very odd if it was a new battery.

 

Might want to see what Toyota has to say about their service history on your car. I had read that Toyota's warranty on a dealer installed HV battery was 3 years.

Posted via the PriusChat mobile app.

 

How many new Toyota batteries fail in less than three years? I suspect very very few.

 

Which makes it "easy" for Toyota to offer a warranty on them if they seldom have to pay out.

Posted via the PriusChat mobile app.

 

If Toyota replaced the battery, it's easy to confirm the fact and the date. And that will help you determine warranty status if, indeed, the battery is bad. Go to Welcome to Toyota Owners and register. Then enter the car's VIN. You'll be able to see everything Toyota has done to it from day one.

If someone else did the work, it's probably not going to be in Toyota's records.