Things worn out in this world, especially if they are batteries over 20 years old. And they wear out in different ways under different conditions of use.
It's not a myth if you have good enough equipment to accurately measure capacity after reconditioning and have a large module library so you can group together modules that are near the same capacity. The best rebuilders can offer a 3 year warranty and not lose money doing that. But yes, from a capitalist perspective a Toyota Stealership will only sell brand new packs even if the only problem with original pack is a corroded sensor wire that takes 5 minutes to fix... Ripping people off as much as possible is the highest moral virtue of a capitalist society.
This is just a battery rebuilder in Tennessee. Dr. Prius app is looking into trademarking "Doctor Prius" but its difficult because obviously "Prius" is already trademarked. Originally it was going to be called Dr. Hybrid app for these reasons, but then Toyota corporate said they were ok with 3rd party use of Dr. Prius.
I meant that balancing a 2004 module with a 2015 module can sometimes be compared to trying to weld a piece of metal that is rusty to the core with rust-covered metal.
Unless you're welding pre WW2 metal to Post WW2 metal its easy to do it at maximum strength and eliminating rust is the equivalent of reconditioning and disposing of any module with a weak cell...
Ya that doesn't make it a myth. My '07 has 155 kmi and daughter's has 325 kmi and both sets of OE batteries are still fully functional. And with my ignorance on batteries I'm figurin you just have to mix good with good and toss out the bad.
According to the wayback machine, DoctorPrius.com was a mobile (refurbished) HV battery installer in the Washington DC area. Posted via the PriusChat mobile app.
I suspect that was a different business... As in, when you're using the trademarked name of Prius in your official business name the words you put before and after that aren't going to be an easy trademark claim...