The "time-out" which occurs after the start of charging I've seen last anywhere from 6 to 20 minutes. Especially infuriating when it occurs at a public charger and one wants to get on with it. IIRC, we even had a report of a public charger shutting off, thinking the i-MiEV had stopped charging.
DBMandrake, interesting that you think it may be part of a balancing routine, as I was under the impression that it was merely to measure the amount of voltage "sag", if any, before continuing with the charging. I had that feature on one of my marine lead-acid chargers and it shut down the charging if the voltage dropped excessively when charging was suspended. Your contention that it may be a balancing dance makes sense, and would explain why this is a seemingly-random occurrence with varying time intervals, both in duration and the point at which the "time-out" starts. Perhaps we might pay more attention to this and even see what CaniOn is saying during this interval.
True bottom-balancing I don't believe is employed in the i-MiEV as our cells never get into that dangerous zone nor (hopefully) spend any time down there; nevertheless, the concept of intermediate-level balancing is intriguing and has not been discussed before on this forum. DBMandrake, thank you for raising this possibility.