When I called the tech about the power steering issue, I asked about the traction battery.

I ask if the traction battery lost one or two cells would we see a trouble code. He said certainly, ever cell is scanned all the time. If one cell gets weak it will give a trouble code.

I asked, do they then replace that defective pack. He said no, we replace the whole traction battery. He said it's not a real worry. He had replaced only two packs since 2000.

He had mentioned this to me before. I misunderstood him thinking he was talking about the plug in packs toyota used for a while. He said toyota abandoned the idea. The problem was that the plug in packs would swell making it very hard to remove any plug in pack.

No worry, I got almost 7 years to go on the pack in my TCH.

 

Data from the Dept. of Energy fleet studies, one other battery swap user, and data from my battery refurbhisment studies indicates there is about 2-5 MPG improvement for the first 3-4 months that then decays to a steady state mileage for the rest of the battery life, until near the end. But I would be interested in anyone else's MPG data to see if this pattern is repeating or limited to the three known vehicles and my bench batteries.

 

Here's my mpg Database if it helps. My slightly lower readings were during the winter months and not the the NiMH batteries. So far this year I have overcome the drop.

You fleet and refurbished battery studies may not be the same Panasonic traction battery used in the Camry Hybrid. I have found the NiMH batteries charge and discharge better during the summer than in the coldest winter months.

Here is a string of my gas mileages per tank starting when the car was new.

https://www.greenhybrid.com/compare/.../car/5583.html