My 2007 Hybrid battery pack has been slowly dying for months. I have 72,500 miles on the car (bought new in Dec. 2006). The IMA light would come on occasionally and clear itself, so I knew the battery was slowly losing sustaining power and it would recharge (down to two bars) many times a day. The light went off the other day and I took it to the dealer to have them check it. They came back, yes the battery is dying and you need a new one. We will order it and it is under warranty (California car- 10 year/150000 mile warranty on the IMA).
So next week I will have the battery pack replaced, with no questioned asked...... I add this because my dealer has always been on the up and up and never given me any hassles. So if any of you are incurring problems, it is probably dealer oriented and not necessarily Honda Corporate.....
P.S. --- even with the battery problem I have been able to sustain around 50 mpg due to the way I drive the car.