i think the range meter is adaptive, that is, it's constantly computing kwh/mile used and updating the range. so the miles remaining is not a good indication of SOC. by the way, i just took a drive right now starting with a full battery again. when i went down the very modest hill near my house (maybe a 50-75ft elevation change) the SOC went up enough for it to start the ICE. it's too bad toyota does not have an 80% (or even 90%) charge option so that you can avoid starting the ICE when you live on a hill... i have a scangauge plugged in so i'll try to be more careful about seeing at what SOC it kicks on the ICE.