bobakka, I think we've pretty-well concluded that Mitsubishi's approach to battery capacity depletion has been simply to reduce the 'range' of turtle. Your supposition that having the 12v battery go down on your car may well have affected the RR calculation, hopefully temporarily.
Our RR, unlike the Leaf's GOM, is very predictable based on how the car was driven over the last 15 miles (24km), and I have yet to have it fail me. Perhaps Mitsubishi had further refined their internal parameters by the time they released the i-MiEV to the North American market?
I think it is out-of-the-ordinary to have turtle kick in while still showing two bars, and then have the car stop almost immediately.
EVs: 2 Wht/Blu SE Prem., '13 Tesla MS85, 3 156v CorbinSparrows (2 Li-ion), 24v EcoScoot(LiFePO4)
EV Conv: 156v '86 Ram PU, 144v '65 Saab 96
Hybrids: 48v1kW bike
ICE: '88 Isuzu Trooper. Mothballed: '67 Saab (orig.owner), '76 MBZ L206D RHD RV