What is the replacement cost for the battery pack?
This will depend on cost after mass production. The standard 1.3kWh NiMH Prius pack costs $3,000 (OEM price). Aims are currently to bring the cost of Lithium packs down to $300/kWh, so a 16kWh pack may cost $4,800 in the future. It’s also likely that the Volt will be lease-only like the EV1, in which case, you won’t have the car long enough to worry about batteries.