How can i install li-ion batterys on my prius

without that, how will we know if they will work long term?

 

There's specific load and voltage testing that can be done to extrapolate the life service of a battery cell. I remember one that was done on an early prototype Sodium cell after someone put 2 or 300k miles on it. I think there was a Youtube video of it. Pretty decent service life when compared against OEM Nickel.

 

why didn't that work for the lithium ion?

 

The same test? I'm pretty sure he did one of those similar tests on a Gen 2 Lithium pack that had 200k+ miles from a customer in Utah or Idaho who ran it into the ground and the results were still amazing. Also different chemistry obviously, different lifespan due to the energy density between the two. The analogy of a Sprinter versus a Marathon runner comes to mind when comparing Lithium/Sodium Ion packs, and Sodium= Marathon runner.