Curious if anyone has heard of this and/or done it? I have 130+k on my 2009, it's still humming (usually 38~40 mpg) but I know it's matter of time before the hybrid battery starts getting weaker.

The Dealer Wanted $4,400 To Fix His Hybrid. He Did It Himself For $7

 

Yes. This is the first place it appeared:

https://imgur.com/gallery/j8Bcp/

Unfortunate that this nugget of hope is still out there with zero follow-up. It's nearly 4 years old now. Given the type of testing described, it's unlikely it was a permanent fix.

The corrosion on the battery terminal contact faces (the only place it matters) was moderate. It was likely the act of resetting the codes via 12V disconnect as part of the remove/install process that restored function. Very common for DIY type repairs to seemingly work for at least short periods of time.

I could be wrong, but I'm dealing with a pretty big data set.

Out of 200+ Toyota hybrid batteries, I've never seen the bus bars cause a false code EXCEPT when someone fails to properly tighten a module nut. However, the majority of those cars were in the Phoenix area where corrosion is negligible.

I collaborate with others, and in the 9 years of combined experience and literally 1000+ batteries, this has happened only a handful of times, and it was in vehicles that spent much of their life in warm coastal regions where bus bar corrosion is horrendous.

The chances of you benefiting from a similar exercise are minuscule unless you live on the beach.