I wonder if the HCHII will operate when the battery dies. Will the battery eventually stop working completely or will it just be very decreased efficiency? Will the car just have decreased performance and will not autostop? Just looking into the future
Yes the HCH2 can be driven without the IMA battery, but you will have warning lights lit on the display and the car is apparently much less powerful and efficient. I don't think anyone would like to use the car like that for a longer time. On the other hand, the battery is likely to outlast the car in most cases. You can look at the HCH, Insight and prius-specific forums to get an idea of how commonly batteries have needed replacement. If the car gets very old and you hesitate about investing in a new battery there will be used batteries available, salvaged from crashed cars. There seems to be a market already for used batteries from older hybrids.
The battery capacity should decline slightly (perhaps 20%) over the years but it doesn't matter until the control unit says the battery is bad. There is probably a threshold for minimum overall capacity, but more likely one or a few cells will go bad first and die quickly so the pack must be replaced. Basically the battery is either OK or dead completely. If it's OK you have all functions (auto-stop, IMA assist, etc.).
There are a few threads on this forum about driving HCH without IMA battery.
No, your car will not run without the IMA battery. Reason being is that there is no traditional alternator to charge the normal car battery. So you can drive it as long as that battery will hold up with no charge, which I would imagine is not that far.
Errmmm... I am fairly certain that the car will start and continue to run with a bad NiMH battery pack. The 12V necessary to run things like the spark plugs, headlights, and practically everything else is derived from a DC-to-DC converter sitting in the power back behind the rear seat, which in turn gets its energy from the electric motor attached to the engine shaft. In the event of a NiMH battery failure, you'd see the dash light up like a Christmas tree, and probably a continual regen of some sort, as the power pack pulls energy off the engine to keep the 12V system going. Turn off the car, then go to restart it, it *should* fire up using the regular starter and 12V standard battery. It will be decidedly unhappy about it, but the car should not drop dead just because the hybrid battery has failed. I vaguely recall msantos actually disconnecting the thing just to see what would happen, but I'm too lazy to go looking for the post.
I've also been the "source" to jump an Navigator. That was pretty darn funny No problems there, either.