The estimates I've seen for all Hybrid battery packs is the life of the car, i.e. 8 years or more and easily 200k to 300k miles. No one yet knows for sure.

However, the Accord will run on gas only. If the battery does not have sufficient charge, it is equipped with a starter (normally not used) and will avoid auto stop.

'05 Accord Hybrid
'05 Odyssey EX-L
'03 1800 Goldwing
'98 Civic EX (16 yr. old daughter's)