Replaced my HV Battery preventatively

As crazy as this may sound to many of you, I decided to replace my HV battery preventatively just a few weeks ago. We happened to be planning to spend a vacation week in Dallas, when I found Texas Hybrid Batteries and saw that for $2400 I could have a Factory new Toyota HV battery installed. Matt from THB said that he had never preventatively replaced a HV battery before, but he understood why I wanted to do it. He did this job in my hotel parking lot in about 1.5 hours. It would have taken me that long just to find motivation to get started lol. Matt is a great guy, btw.
I live in Springfield, MO (6.5 hours from Dallas) and I had planned to just DIY this project when the inevitable HV failure hit. I figured it would cost me $2300 or so to get a battery from Toyota of Dallas. Plus the hassle of paying extra $$$$ initially for core charge, and sending the core to Dallas. In the end, I am very glad that I had this done for me instead. This is the car I take my family on long road trips, And I need to be able to depend on my Prius! My worry was that I would have HV failure while I was far from home, and would end up paying more $$$$ than I wanted. Doing it preventatively gave me the opportunity to get a good price. The peace of mind of having this done is priceless, and I now get 46-49 mpg which is about a 3 mpg improvement from before.
Any of you who live anywhere within a decent drive of DFW, It might be worth a trip there if your battery is showing signs of going south.

 

I will post a pic when I get to Chicago tomorrow. I'm on the road again with the old Prius right now.

 

My understanding is that he keeps the good cells and groups the bad ones together from other customers and returns all the bad ones as core. He doesn't make much money off of the install of a new battery, but likely makes more on the back end selling the refurbished batteries. Works for me.

 

Here's a pic of the newly installed battery. Matt went ahead and opened up the battery case at my request so that I could verify that the cells were new. In my case, the cells were made in February 2016. Note THB provides a 4 year warranty, in the unlikely event of failure.
I forgot to mention as part of the install Matt installed a fan that had been cleaned already (used not new) and cleaned my throttle body out.

 

The individual cells have codes imprinted on them. Toyota has a sheet that explains the month and year that the cells were manufactured. I'm not sure if I have the sheet at home or not but I can post it here when I am back early next week.
The sheet is for Toyota technicians. The purpose of it is for Toyota technicians to determine if a Prius owner has somehow tampered with the HV battery, therefore voiding the warranty. It discusses how the 28 cells should have matching imprinted #'s, how to determine when those individual cells were manufactured, and even the proper position of certain screws. I'm guessing that some Prius owners out there have pulled some shenanigans that necessitated this.

 

I had 148,000 when I had it replaced. Btw the battery in my car was produced in August 2006.
Over the last 6 months or so my battery had been fluctuating from 6 or 7 bars down to 2 or 3 bars more frequently and much much faster than before. My mpg was slightly down, 42-43 on the highway and 45 in the city. Even though I only bought the car in October 2013 I could tell this was not normal operation and that the end was nearing.
Matt just emailed me results of his testing of my old battery. He said it was actually in worse shape than most of the failed batteries he normally sees. Despite this, he said it would not be possible to determine how much longer I could have gone without replacement. But he did say it turned out to be a good decision to do so.

 

I'm not 100% but I want to say that Japan was imprinted on those cells. I do remember feeling good about what I saw, between being able to verify that the serial #'s printed were matching and produced in February 2016, as well as the receipt from Toyota-Matt had actually picked up my battery from the Toyota dealership he buys from the day he did the job. For what it's worth, Matt said mine was only the third battery he had seen with 2016 dating, and this job was done on 5-31-16.


Another interesting thing to note from my conversations with Matt ( he allowed me to watch him while he did the job so we got to talk a lot) was that these new Toyota batteries used 3rd gen cells. Apparently the 3rd gen works the battery just a bit harder to extract better mileage than the 2nd gen. So he said using new generation cells in this 2nd gen ( that doesn't work the battery quite as hard) is a great combination. Whether that means this battery will last longer than the 10 years my old one did will be interesting to see.