Hi Geoff,
We are taking a worst scenario. There are some sensitivities which would not be appropriate to discuss in this forum. Battery power is supposed to last at least 2 hours but in this case it didn't. The transportation is from hospital to hospital in an ambulance.
Well, failure can occur in almost anytime and anywhere. What I see is how we are prepared for the worst and have a protocol or process to take care of the situation.
We become wiser each time.