Interesting battery info I found.

NiMH battery technology, how to charge Nickel Metal Hydride
Batteries tutorial for design engineers, as well as NiMH chargers.

This is rather interesting, but not sure how accurate. This means a 6.5Ah module would be charged to 10.8Ah?

Also since the car itself doesn't use all of the capacity, wouldn't that be rather moot?

My hobby chargers never see this delta V bump, so I always charge at 500MAh, which is slightly less than C/10, but a nice, safe charge. I terminate at 7200MAh. But some people do as much as 9500MAh, which seems a bit silly as I don't think you can push more capacity into the battery than it has to begin with.

According to this site, a NiMH battery is fully charged at 1.4V per cell, so on a Prius module, this would be 8.4 volts, usually my modules are at 8.4-8.5V a couple hours after they are done charging.
I think going over 7200MAh is a waste, but if others want to say why or why not, I'm all ears.