Recent content by lphe

For a more detailed analysis of how fast acceleration impacts my car, see the posts I made in this forum: EV Dynamics Physics Experiment - Page 2 - Energi Driving Tips & Tricks - Ford Fusion Energi Forum

The following is an explanation of why fast acceleration less efficient than slower acceleration. The plot below is the Electric Motor Map for a Prius. The x axis indicates rpms. The y axis indicates torque. The contour lines indicate efficiency. So at 20 Nm of torque and 3000 rpms, the...

Yes--I don't want to waste energy from the battery to heat the car. When the heater core cools down, I let the ICE warm it back up rather than drawing power from the battery to warm the heater core with the electric heater. I need to run the ICE anyway for my 60 mile commute. I might as well...

The car is pulling in cold outside air through the heater core to warm it up and direct it into the cabin. That quickly cools down the heater core. When the ICE is off, the heater core is isolated from the ICE coolant. The electric heating element is then used to heat the coolant isolated in...

If I were to buy a Model S, then I would need two cars. That is a great deal more hardware redundancy than in a PHEV. The range of a BEV is not going to suit my needs in the winter.

93% of the trips that I make with my PHEV are well within its 25 mile EV range. My commute to work is 8 miles. For such short trips, a pure hybrid looses much of is efficiency advantage to pure ICE vehicles. A PHEV is much more efficient for short trips. On my 60 mile commutes, I use about...

The last item that has a big impact on EV range is cabin heating. This plot shows temperatures for my 60 mile commute at -2 F. The car isolates the coolant in the heater core from the ICE coolant when the ICE is off and uses an electric heater to heat that coolant, if necessary. The red...

I have attempted blocking the grille with foam pipe covers. I monitored all the temperatures in the car for my commute when it was -10 F with and without the covers. The pipe foam covers had absolutely no effect at that temperature. All the temperatures (transmission, cylinder head, heater...

How do Prius owners preheat the power split device? The following chart shows the transmission fluid temperature for a 60 mile commute in the winter at -5 F (blue line) and in the summer at 68 F (red line). In the winter, the temperature never gets above 100 F even with the ICE running to...

The charts were not made driving a Tesla. But I would expect similar results. The max power output of the battery in my car is 68 kW. I don't know how things would change for a P85D. You would probably need a racetrack to properly measure the effects of fast acceleration. I'm doing this...

The chart from the link below shows the viscosity of transmission fluid vs. temperature. At 0 C (32 F), the viscosity is many times greater than what it is at 50 C (120 F). I would expect the transmission fluid used in EVs behaves similarly. This explains the significantly reduced mileage...

Of the total 0.009 kWh of additional energy for fast acceleration, 0.006 kWh is due to traveling the same distance in a shorter period of time. This is the difference between the dashed and solid green lines. But it is very difficult to measure such small differences accurately. But note...

The green lines take into account the additional friction (aerodynamic drag, rolling resistance, internal friction) associated with higher average speeds during fast acceleration vs. slow acceleration. The difference at the end of 0.25 miles is about 0.006 kWh more energy consumed from the...

I have attempted to measure the amount of energy consumed during slow acceleration vs. fast acceleration for an EV. Fast acceleration used more energy. The following chart shows my analysis. The dashed lines are fast acceleration and the solid lines are slow acceleration. In both cases, I...

I have been tracking the Energy Capacity and Temperature of the battery each morning for a year. The following plot shows how the energy capacity of the battery varies with temperature. The capacity of the high voltage battery (HVB) is 7.2 kWh. Capacity falls by about 8% as the HVB...