2006 Honda Civic Hybrid won't hold a jump?

[zuckie44]

My husband has a 2006 Honda Civic Hybrid and we were going to use it on New Year's Eve. The car wouldn't start so we used my car to jump start it. It worked fine for the hour we drove it and then parked it for 5 hours. When we went to use it to drive back home, it wouldn't start and we had to jump it again. It was fine the entire way home but it wouldn't start the next morning we went to use it. I'm going to jump it again tomorrow morning so I can bring it to the Honda dealership but does anyone have any suggestions as to what it can be? I'm not sure if it's the battery but I read online that the battery packs cost around $3,000 with an 8 year/80,000 mile warranty. The car is under both the year and mile limits so I'm hoping the battery pack will be 100% covered.