Well, the weather was pretty good the past few days so I decided to go for a "how many EV miles can I get in a day with L1 charging only" run. I combined with with going for a "personal best on one charge" run for the first leg of the event. Starting out, ambient temperature was 68F, tire pressure 38 psi, and the guess-o-meter saying I had 53 miles of range available. I did local town driving, with zero traffic I set up a route that was 6 miles long with a turn around at each end, with one stop sign other than the turn around at each end. Actual driving speed was 35 mph and average speed with the stops and turnarounds was 32 mph. I was able to make 78.9 miles driven on 13.9 kWh used. The use screen switched over to counting gas miles for the last 0.2 miles of that leg even though the gasoline engine never actually fired up, making the EV miles 78.7. So, my miles per kWh under those driving conditions was 5.66 miles per kWh. I then charged to 80% in around 9 hours and did a run at faster speeds since it was day and I didn't want to try driving at slow speeds in town with traffic around. Weather conditions were the same, and I drove my normal commute but a bit longer (drove past work, and turned around a few miles later) so almost all at 55 mph, and I used 11.1 kWh to go 45.9 miles, so my miles per kWh were 4.14 miles per kWh. The charging to get up to 80% again took a bit longer due to temperatures dropping down to 58F, so my plans to do another slow run to eke as many miles as possible were scrapped to do a quick run to run out the battery before the 24 hour cycle ended. That last run I made 40.5 miles on 10.9 kWh, but 1% of that was climate control for periodic defogging of the windshield, so call it 10.8 and 3.75 miles per kWh.
Total of 165.2 miles on 35.9 kWh used for average miles per kWh of 4.6 miles per kWh. I had about a half hour left in my 24 hours, so I didn't waste too much time.
Now, so theory and math
Figure that 80% charge is 11 kWh of power, and you start with a full battery... do you actually get more miles in 24 hours by driving more efficiently? Figure identical first leg to what I had in reality, and assume I could have duplicated the route without causing road rage during the other two runs, and that average charging time to get to 80% is 10 hours. First run takes 2.5 hours, and gets me 78.7 EV miles. After 10 hours of charging I make a 62 mile run at 35 mph driving speed, average speed of 32 mph, so about 2 hours. This leaves 9.5 hours left of your 24 hours, charge for another 8 hours (about 64%) and you can drive for 1.6 hours... but your only have 1.5 hours left in your 24 hours, so assume you lost a few min along the way... call it 48 miles. So in theory someone willing to go that extra mile could get 188 miles on L1 charging. Now to see if the efficiency boost from driving slow makes a real difference we need to subtract a half hour of driving, since I finished my "real world" run at 23 hours and 30 min. At these speeds cutting half an hour shaves off 16 miles, so I would be down to 172 miles... still better than higher speed driving, but only by 7 miles.
Later,
Keith
