July 14: Figuring out rangeWed, 14 Jul 2010
Topping off the tank seems to work best. By keeping it full I get a lot more freedom and a lot less range anxiety. Today I drove up to Pasadena twice, down to Los Angeles, west to Santa Monica and all the way back to my office in LA. Adding it all up I went 58 miles. After the first six miles I plugged it back in for an hour to top it off, so I can't say I went all 58 on a single charge. But I did go somewhere between 52 and 58 miles on about 10 bars or 10 kWhs. So that's a little better than five miles per kWh. Multiply that by the 16 kWh capacity of the battery and you have 80 miles of range based on how I drove today. A lot of today's driving was on the freeway, about 30 of it with the a/c on. Maybe 20 miles was in stop-and-go traffic. So to go at a theoretical 80-mile range in far-less-than-ideal traffic conditions is pretty good.
Figuring out these numbers is something of an inexact science. With a gasoline car you drive a certain distance, starting with a full tank, then fill up the tank and you know almost exactly what gas mileage you got. Harder to do that with electricity, at least as it is presented here.
Now, about 10 p.m., I'm heading down to the parking structure, unplugging the i-MiEV, which might be topped off, and heading home. Lemmee see--it's been charging six hours so maybe it won't be topped off at 120 volts. It should be two bars from the top of the fuel gauge.
By Mark Vaughn