One problem related to battery dead has been reported for the 2006 Honda Odyssey. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2006 Honda Odyssey based on all problems reported for the 2006 Odyssey.
Brand new replaced battery and electrical start issue happening again. Sometime the car wouldn't start as if the battery is dead, then wait 10 minute and everything works (tho all the code reset as if the battery was disconnected). This is what caused us to replace the battery after dealer couldn't find any issue. It worked for a few weeks but problem is back. Dealer can't replicate issue since of course it starts fine. But there is some inherent issue with Odyssey electrical issue as a lot of people have this issue.