Have had my Prius 3 for just over 2 weeks and the battery indicator for the first time had all bars lite up, they didn't stay on for long (15-30 seconds). for the past 2 weeks the top 2 bars were black. Was going down hill for a few miles when the top 2 bars turned on showing full charge. Is this normal?
Yes, that is normal. Research shows that keeping a charge in the "middle" of the battery's range prolongs its life. So, the computer tries to keep the state of charge greater than two bars but less than (whatever the max minus two is)
Yes, it doesn't like being charged to that point. Don't be surprised some day when all the segments are on and the eng fires up at a stop light. The system will discharge itself by spinning a dead engine.
2010 Prius III w/nav/solar. Blizzard pearl and a nice quiet set of new Michelins.