My 2005 Vette battery goes dead at car wash. They vaccume trunk, leave both doors open to vac. then wash & again leave both doors open, radio on. Go to start within 15 min & dead battery. How can it go dead in 15 min with that little power drain? I have taken battery to be checked & advised battery is OK. Last time it happened, it took a set of jumper cables attached to battery terminals plus a battery jump pack attached to the power box to get it started?