Battery level change?

That's what i thought. I never noticed it go down until after it was run down into the purple zone by the carwash people.

I paid attention to what happened when i had lunch in the car last Friday. It was at 6 bars when i parked. I sat there for about 20 minutes with it in ACC. When i turned it back on (to drive up to the roof, i had eaten inside the structure), it had 5 bars. When i got to the roof, i sat in the car in Ready mode listening to something on the radio. In 5 minutes, it dropped 3 bars. Is that normal, for it to drop so fast? This has happened before, since the carwash, it seems to be normal for my car. It didn't fluctuate. It was at 5 bars when i headed for the roof, having gone down one bar during the 20 minutes i was eating in ACC mode. Then, it took maybe one minute to drive to the roof, i parked and sat for 5 minutes and it went down one bar, then two, then three before i turned it off. When i came back after work, it was the same as when i left it. Then, when driving, it came back up a little at a time.

How long roughly should it take to drain either battery? This was never an issue in my Accord, i didn't give it any thought. Is this related to the hybrid technology?