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The following posts describe an experiment I performed the other day with the car to understand the forces and their effect on the motion of an EV. For the first part of the experiment, I drove the car with cruise control set to various speeds along the same section of road and measured the electrical input power and mechanical output power of the motor required to maintain constant speed. This allowed me to plot the power required to overcome friction (aerodynamic drag, tire rolling resistance, and internal frictions) as a function of speed. Next I did a coast down on the same section of road. With the car in neutral, I recorded time vs. speed as the car slowed down. I also recorded the power output of the motor. The power output of the motor is negative during coast down. Internal friction inside the motor is slowing the car down. The outside temperature was 63 F. There was no wind. The road that I am using is level to within 1.5 feet. I drove the car for approximately 20 miles, with the ICE running, prior to the experiment. I wanted to make sure the car was thoroughly warmed up before starting. The temperature of the drivetrain components in a car have a huge impact on the internal friction within the car. When cold, the car will require significantly much more energy to maintain constant speed. As the car warms up, each time I repeated a portion of the experiment, I would get very different results.

Anyway to charge up the Energi battery using the gas motor? If you turn on the gas motor for the first time in a trip, since it needs to stay on to warm up anyways, it will use the energy generated to charge up the battery for driving around in electric mode. This seems to put a few percent of charge into the battery very quickly. Is there anyway to keep the motor on to charge the battery up, a la the Volt? It would be very nice to have more pure electric mode in situations.