I'd watch the 12 volt battery voltage. It should be at at least 12.7 volts at rest, and probably above 13 while the car is running. If it is within these ranges the IMA is probably still acting as an alternator in which case I would think the car would be ok. If the 12 volt is less than said above then your 12 volt stuff is drawing off of the little battery and I wouldn't plan any long trips. If it is low in the mean time I'd recharge it at every opportunity. Because eventually if the 12 volt dies and there's nothing charging it the car will stall out and you won't be able to restart it.