[hayden55]

Yup gen 3 targets 60 +/- 2% SOC as a midpoint. It will charge up below and burn it off above. If you get a scan gauge you should be able to see where load peaks and that will be around your peak BSFC I assume similar to the graph posted before. My gen 3 is running a non-EGR map and peak load used to be something like 92% the entire time it never moved, but now it's 60-75-85-90 depending on rpm, and peak is achieved around 2050 rpm.
I pulse and glide my gen 3 prius with the SOC gauge and RPM gauge and Fwt gauge on my scan gauge with decent success even with my EGR delete and 205/70/15 tires (90 day mpg is about 52mpg still). Gen 3 will let you shut the engine off at 45mph and below and with my tires I can do engine off up to 46. If it makes you feel better i only get like 42mpg on the interstate going 70mph.

Pretty much my main goal when driving is to stay between the midpoint plus and minus for best mpg so I use pulse and glide to get the most out of the extra energy. Going above is okay not a big deal but going below really kills the mpg. Basically just a stop start system for me to get pretty good gas mileage. On your battery I wouldn't worry about it being bad as you really don't need to rely on it a ton besides using it for stop and start. Driving in EV mode is mostly a detriment to my mpg unless i just need to inch forward 50 feet to a stop sign. Each stop start registers on my 2010 gen 3 as 0.4% SOC.