After searching the archives, I've confirmed that our cars use valve-stem tire pressure sensors with batteries, but are only activated when the wheels are turning.
I've acquired a second set of i-MiEV rims (steel) complete with nearly-new tires from a salvaged car. The tire pressure warning light didn't activate during the first two low-speed test drives, but now starts blinking as soon as I start moving and lights up steady after a minute or so.
Does anyone know if the TPMS sensors have to be 'linked' to a particular car, and whether the sensors or their batteries can be replaced without dismounting the tire?
In full disclosure, this new-to-me set of tires came from a Hurricane Sandy-flooded car, so there's a chance that the sensors experienced saltwater intrusion, though the valves had their caps on and appear pristine. Also of note on those salty steel wheels, the only corrosion was on the welds, which I repainted. That may be something to watch for as cars age in the 'salty road zones'.
2012 i-SE "MR BEAN" 87,000 miles
2012 i-ES traded at 21,648 miles
1983 Grumman Kurbwatt,170 kW, 32 kWh
1983 Mazda RX-7 EV 43 kW 10 kWh
1971 "Karmann Eclectric" EV 240 kW 19 kWh
1965 Karmann Ghia Cabriolet