Not sure what you mean, but the BCM will only charge up to 80% and down to 20%. Hence, 80% could be considered "full" and 20% could be considered "empty." Because you can't use the top 20% or the bottom 20%, the effective capacity of the pack is 60% of it's actual capacity.
20%-80% isn't that bad of a range. It's only 60% of the total capacity, nowhere near a deep cycle.
I suspect the Toyota uses a similar range, though it has a "center seeking" charge where it uses electric more aggressively at high charge and charges more agressively at low charge. Since the "center point" on the Toyota is 56% (I think) I find it unlikely that 50% would be the lower range.
___ANL and NREL (the government labs) have quite a few studies and details on the packs of the Insight and Prius’. I would suggest that you start there because there is quite a bit to learn about actual pack SoC’s vs. what the meters are displaying. Both Honda and Toyota are conservative with a 20 - 80% on the pack is ~ = 0 and 100% on the SoC meters.
___Wayne R. Gerdes
___Hunt Club Farms Landscaping Ltd.