larryh

There is a wide variation in the amount of energy required for a commute depending on temperature, wind speed and direction, traffic, and other factors. The following table shows the variation in energy required and fuel consumed for a 60 mile commute. There is linear correlation between the amount of fuel consumed and the energy output of the ICE. Perhaps 90% of the variance in MPG for the same commute is from wind, temperature, traffic, and other factors that are beyond your control that affect how much energy is required. The trip that consumed the most gas required 49% more energy than the trip with the least amount of gas consumed. (Note each trip also consumed about 5.9 kWh of plug-in energy in addition to the gas). Energy Output of ICE (kWh) Fuel (gallons) 6.531893327 0.593525846 6.662831782 0.591398591 6.769850679 0.609514536 7.02045321 0.616525337 7.348378985 0.64225446 7.593411538 0.671953975 7.655557735 0.678221184 8.001970951 0.697196885 8.331743778 0.726306456 8.602420337 0.707282661 9.710379355 0.80417292

I think the efficiency of the motor in generating electricity is in the upper 90% range. I can estimate this as follows. At around 15 kW, from the previous posts, the efficiency of the motor in producing power to propel the car was 85%. When I drove to work today, I verified that the motor was 85% efficient at this power level. However, efficiency decreases with power output. At about 5 kW, the efficiency fell to about 72%, i.e. 72% of the electrical power from the HVB was converted to mechanical power by the motor. Let’s assume the generator is equally efficient at generating power. From the previous posts, during steady state when no power was being supplied to the HVB, the generator was providing 5.4 kW of mechanical power and the motor was consuming 7.7 kW of mechanical power on Sunday’s commute—there was a power loss of 7.7 – 5.4 = 2.3 kW. For Fridays’ commute, the generator was providing 4.9 kW of mechanical power and the motor was consuming 6.9 kW of mechanical power—there was a power loss of 6.9 – 4.9 = 2 kW. Assume that all the power loss is associated with the conversion between mechanical and electrical power by the motor and generator (I don’t know how valid this is). Since the generator is 72% efficient, on Sunday, it must have been consuming 5.4/0.72 = 7.5 kW of electrical power. On Friday, it was consuming 4.9/0.72 = 6.8 kW of electrical power. The electrical power was provided by the motor, so on Sunday, the motor was 7.5 / 7.7 = 97% efficient in generating electricity. On Friday, it was 6.8 / 6.9 = 99% efficient. Due to measurement error, I can’t be certain of the exact values. So I’ll assume the efficiency of the motor in generating power is approximately 97%. This is consistent with the observed efficiency of the motor in generating electricity during regenerative braking. That means the that 95%*97% = 92% of the power from the ICE used to charge the HVB is converted to electrical power (there is a 5% loss in power when transmitting power from the ICE through the planetary gear system). This also means that the efficiency ratio in post 81, could be as high as 92%*80%/81% = 91%. So to calculate the amount of gas consumed by the ICE to charge the HVB, assume the ICE is 37% efficient and that 92% of the power from the ICE supplied to the motor to generate electricity is converted to electricity. The capacity of the HVB in the Fusion Hybrid is 1.4 kWh. Furthermore, I estimate that about 97% of the energy supplied to the HVB is stored in the HVB. If the ICE charges the battery from 20% to 80%, then the amount of energy applied to the HVB must be around 1.4 * (80% - 20%) / 97% = 0.87 kWh. If the ICE is 37% efficient, each gallon of gas provides the ICE with 0.37*33.705 = 12.47 kWh of mechanical energy. So the ICE must consume about 0.87 / 12.47 = 0.07 gallons of gas to charge the HVB from 20% to 80%.

Actually, I think only about 87% of of the ICE energy applied to the motor to generate electricity is converted into electricity. I already determined that 17 - 12% = 5% of the power from the ICE is lost by the planetary gear system, so that power does not even make it to the motor (see post 87). I believe the motor is at least 92% efficient in converting mechanical power to electrical power from the data plotted above (and maybe as high as 94%). So that means at least 95%*92% = 87% of the ICE power applied to the motor to generate electricity is converted to electricity. That would imply the effective efficiency of the recovered energy when driving in EV mode is about 87% rather than 89% (see post 81).

Since I have the Fusion Energi, my car does not work quite the same as the Fusion Hybrid. On a level freeway at constant 65 mph, the car does not normally run in EV mode. I switched from EV Later to EV Auto to turn off the ICE and run in EV mode so I could compare the operation of the ICE and the electric motor. The plot below details what happened when I switched back from EV Auto to EV Later to discontinue EV operation. The switch occurs at time 6:57:14. The top light blue line shows instantaneous MPG. It rises from 30 MPG when starting to charge the HVB to about 45.6 MPG after charging has completed. The next darker blue line shows the power output from the ICE. It starts at about 30 kW when charging begins and drops to about 17.6 kW after charging has completed. The third blue line from the top is the power output from the generator. It is a relatively constant 5.0 kW. The orange line shows the change in energy of the HVB. I arbitrarily chose 0 kWh as the starting energy in the HVB (it actually had 2.91 kWh of energy left). ETE stands for Energy to Empty, i.e. the amount of energy in the HVB. The car added 0.122 kWh of energy to the HVB. That is an increase in SOC of 1.7%--the capacity of the Energi HVB is 7.14 kWh. That corresponds to a change in SOC of 20% on the 2D hybrid battery icon. The green line shows the power applied to the HVB (when negative) or drawn from the HVB (when positive). When switching to EV later mode and charging begins, the car initially applies 10 kW of power to the HVB. The red line shows the power being consumed by the motor to generate electricity. It starts consuming 15 kW of power to charge the HVB and reduces to 7.1 kW after charging completes. I don't have a good way of determining how much of the gas consumed went to charge the HVB. By computing the area under the power curve for the ICE, I estimate that it output about 0.12 kWh of energy to charge the HVB. But that is not very accurate. 0.12 kWh was the amount of energy that was stored in the HVB so I get 100% efficiency which is not right. I'll just assume that the ICE is 90% efficient in generation of electricity, so 0.122/0.9 = 0.136 kWh of energy was required. Assuming the ICE is 37% efficient, that is 0.011 gallons of gas. Note that the ICE efficiencies that I reported in my previous posts are probably a bit low. The fuel data that is recorded is always overly pessimistic. For this trip, the logged data showed I had used 0.67 gallons of gas. The car reported that I had only used 0.62 gallons of gas. So the efficiencies reported above should probably be multiplied by 1.08 to get the correct value. The ICE efficiency for the portion of the trip plotted below was 37%.

For my commute home, I recorded more data to verify the previous results. This time, the temperature was 86 F and there was a headwind. Previously it was 62 F and the wind was calm. I did not use AC nor have the windows open. The ICE output 19.6 kW of power this time to maintain 65 mph. The net power to the HVB was approximately 0 kW. The electric motor was consuming 7.7 kW of power to generate electricity and recycling that electricity back to the generator which then supplied 5.4 kW of power that sums with the 19.6 kW of ICE power by the planetary gear system. So this time 7.7 - 5.4 = 2.3 kW of power was being used to control the planetary gear system. That represents a 2.3/19.6 = 12% loss of power used to control the planetary gear system. The efficiency of the ICE was 34.5%. In EV mode, the motor required 16.2 kW of power to maintain 65 mph. Again, using the motor to power the car is more efficient than using the ICE. The motor only needs to generate 16.2/19.6 = 82% of the power required by the ICE to propel the car. Previously, the percentage was 81%. So I am getting consistent results. Apparently there is a total loss of 19.6 - 16.2 = 3.4 kW from the planetary gear system, or 3.4/19.6 = 17% when the ICE transmits its power through the planetary gear system. The power drawn from the HVB was 19.6 kW. Accessories used 0.6 kW of power. So the efficiency of the motor was 16.2/(19.6-0.6) = 85%--the same as before. I will have to see if I can determine the power at the wheels to determine the loss of power being transmitted from the motor to the wheels.

From the data I have collected, the estimated average efficiency of the ICE producing different power output levels is: Power Efficiency 10 28% 15 32% 20 35% 25 36% 30 35% 35 35% 40 35% 45 34% Since the ICE does not generally operate at low power levels, it is difficult to get good estimates at 15 kW of power and below. For the 65 mph freeway commute when the ICE was producing 17.6 - 23 kW of power, the efficiency was 34.6%. If 89% in the previous post is correct, then the car should run in EV mode when the ICE efficiency falls below 0.89*0.36 = 32%, which is around 15 kW and is consistent with what I observe in the plots in the previous posts.

From my previous post, I mentioned that perhaps only 72% of the energy provided by the ICE to charge the HVB is actually recovered during EV operation. That is a big loss in efficiency. However, it is not really as bad as it may seem. The electric motor uses significantly less power to propel the car than the ICE. For my 65 mph commute, the ICE needs to provide about 17.6 kW of power just to propel the car. The electric motor is consuming 6.9 kW of this power to generate electricity and recycling that electricity back to the generator which then supplies 4.9 kW power that sums with the 17.6 kW from the ICE via the planetary gear system. So 6.9 - 4.9 = 2 kW of power produced by the ICE is being used to control the planetary gear system. The ICE has to produce at least 2 kW more power than the motor. Actually, it has to produce more power than that to overcome additional transmission losses (1.4 kW of additional power). The motor requires 14.2 kW of power to maintain the same 65 mph speed on the freeway. That is 14.2 / 17.6 = 81% of the power required from the ICE. So even though only about 72% of the energy supplied by the ICE to charge the HVB is recovered in EV mode, EV mode requires significantly less power. Effectively, we are recovering 72%/81% = 89% of the energy provided by the ICE to charge the HVB. That is a lot better than 72%. Having the ICE charge the HVB is not quite a free lunch (100% efficiency), but 89% is not all that bad. Note that the power drawn from the HVB to power the motor at 65 mph is 17.0 kW, which includes 0.3 kW of power to run the car's accessories, i.e. fans, radio, lights, etc. The motor is thus 14.2 / (17.0 - 0.3) = 85% efficient at 65 mph.

The final drive ratio determines the point at which the car switches from positive to negative split mode of operation. I am unsure of which mode of operation is more efficient. They seem to be about the same to me. The most efficient mode of operation is parallel mode, which occurs at the transition between positive and negative split mode of operation, where the actual drive ratio currently being used is the final drive ratio. Raising the final drive ratio moves the transition from positive to negative split mode to a higher vehicle speed.

The following is a plot of a portion of my commute traveling on the freeway at a constant 65 mph. Similar to the previous city driving commute, the ICE operates between 18 and 35 kW. The motor operates when the power required is less than 18 kW. Until the ICE turns off at 6:50:30, the ICE is charging the HVB while going up a slight hill. The car operates in negative split mode at 65 mph. So the generator is consuming electrical power (the Gen line is above the x-axis) to provide the torque required for the ICE to transmit its power to the planetary gear system and propel the car. The generator is producing mechanical power which is summing with the ICE's power via the planetary gear system The electric motor is consuming mechanical power (Motor line is below the x-axis) to generate electrical power which is fed back to the generator and used to charge the HVB (HVB line is below the x-axis). The ICE turns off at 6:50:30 when going down hill. The electric motor is now powering the car--propelling the car requires less than 10 kW of power. It is more efficient to operate the electric motor here than to use the ICE. So you want the ability to have the electric motor power the car at 65 mph At 6:50:40, the ICE starts back up again going up another hill when power requirements exceed 18 kW. You can see a large positive spike in the power output from the motor attempting to turn the ring gear of the planetary gear system to start the ICE. At the same, you see a large negative spike from the generator as it tries to prevent the sun gear from rotating, allowing the power output from the electric motor to flow to the planet gears and consequently to the ICE to start it. Here the electric motor is consuming power from the HVB and the generating is providing power to the HVB. We now repeat the original uphill cycle. The ICE initially generates about 10 kW more of power than required to propel the car which is used to charge the HVB. About 9 kW of power is applied to the HVB. At time 6:51:42, there is another downhill. At this time, the ICE power has reduced to 20 kW, which is sufficient to propel the car and generate approximately 1.5 kW of power for charging the HVB. During the second downgrade, the hill is steep enough to get some regen from the electric motor initially. As the hill flattens out and becomes an upgrade, the electric motor provides the power to propel the car until about 18 kW of power is required and the ICE starts again. Again, the ICE produces about 30 kW of power which is sufficient to propel the car and provide the HVB with about 9 kW of power. Eventually, after charging the HVB, the power output of the ICE reduces to about 18 kW, and the car no longer charges the HVB. There are only minor fluctuations in the power applied to or drawn from the HVB as the car adjusts to slight changes in the grade of the freeway.

This plot shows my 8 mile commute to work in hybrid mode. The SOC is the SOC displayed on the 2-D battery icon on the car's display when in hybrid mode. Positive power from the motor indicates the motor is propelling the car. Negative power indicates the motor is being used for regenerative braking or by the ICE to generate electricity. The commute is on city streets with a speed limit of 55 mph. Speed is shown in red. Ignoring when the ICE is warming up, the ICE only operates between 20 kW and 40 kW in its most efficient operating region--the ICE efficiency is around 35%. The excess power beyond what is needed to propel the car is used to charge the HVB. When the power required to propel the car is below 15 kW, the car runs in EV mode. Since the ICE does not generally operate below 15 kW, I'm not certain what the efficiency is at this power--probably below 25%. So as indicated in my previous post, while charging the HVB, the ICE is 35% efficient and the car is able to recover about 72% of that stored energy in EV mode. So, 72%*35% = 25% of the energy released by the combustion of gas used to charge the HVB will go to propelling the car later in EV mode. EV Mode occurs when less than 15 kW of power is required and the efficiency of the ICE at that power level falls below 25%. So it is better to charge the HVB and use the energy later in EV mode rather than to run the ICE in an inefficient operating region. Note that when the ICE first starts up, there is a spike in output power from the motor as it assists the ice in accelerating the car. Gradually, the power output falls and the motor begins consuming power power from the ICE to charge the HVB. Most of the charging of the HVB is done during regenerative braking, converting the kinetic energy of the car provided by the ICE to electricity. There are a couple of anomalies where the ICE started and ran at idle speed (1150-1500 rpm) at time 3:10 and 3:11:30. I'm not sure why it did that. Note the ICE was only at 110 F at the time--so it was not really warmed up. When driving at a constant 65 mph on the freeway, the ICE generates about 20 kW of power and after initially charging up the HVB, no further power is used to charge the HVB. The car does not operate in EV mode unless there is a significant downgrade and significantly less power is required to propel the car.

Based on my observations, when the ICE is providing between 20 to 35 kW of power, efficiency is around 35%. Of the 33.705 kWh of energy released from the combustion of a gallon of gas, 35% of this energy is converted to mechanical energy used to power the car and charge the HVB. When the power provided by the ICE is less than 20 kW, efficiency starts to fall. For example, when providing 10 kW of power, the efficiency might drop to 25%. (It requires about 20 kW of power to go 65 mph and about 10 kW of power to go 50 mph.) The efficiency the motor/generator in generating electricity is probably around 90%, i.e. 90% of the mechanical energy provided to the motor/generator is converted to electrical energy. The efficiency of the motor/generator in providing mechanical power is about 80%, i.e. 80% of the electrical energy provided to the motor/generator is converted to mechanical energy. This means about 90%*80% = 72% of the mechanical power provided by the ICE to charge the HVB is actually recovered in EV mode. There is little advantage in having the ICE charge the HVB when it is providing 20 kW of power (around 65 mph) or more to propel the car. You are only going to recover 72% of the energy produced by the ICE when in EV mode. So 35% of the energy released from the combustion of gas is converted to mechanical power to power the motor/generator, and then 72% of the resulting electrical energy is converted back to mechanical power to propel the car later in EV mode. The overall utilization efficiency of this portion of the gas that was used to charge the HVB and later power the car later in EV mode is then 35%*72% = 25%. If you now run the car in EV mode at 65 mph using the energy from this gas, you are now effectively only getting 25% efficiency from the combustion of that gas and have lowered the overall mileage (mpg) of the car. If you had not used the gas to charge the HVB, and instead used it to propel the car, you would be getting 35% efficiency. Charging the HVB and running later in EV mode reduces mileage (mpg) at 65 mph. However, if you could utilize the energy stored in the HVB at a later time when the power required drops below 10 kW and efficiency of the ICE drops below 25%, then it is advantageous to charge the HVB at 65 mph. With the gas used to charge the HVB, you are effectively getting 25% efficiency. If you had instead used the gas to power the ICE and propel the car (without charging the HVB), you would have gotten less than 25% efficiency since ICE efficiency has dropped below 25% at 10 kW of power. This can happen during downgrades on the freeway. So you might want to charge the HVB while driving 65+ mph so you can power the car later in EV mode while driving on a downgrade. (There are additional considerations, such as having the HVB assist the ICE to reduce the load and drive it into a more efficient operating region.) Better yet, is to charge the HVB when the power required to propel the car is less than 20 kW. The additional power required to charge the HVB increases the overall ICE efficiency from maybe 25% to 35%--the ICE is providing 20 kW of power rather than 10 kW of power. So now you are getting 35% efficiency from the gas that is used to propel the car (rather than 25%). In addition, you are going to get at least 25% efficiency from the portion of the gas that was used to charge the HVB. So charging the HVB and running later in EV mode increases mileage (mpg) at slower speeds (around 50 mph or less). The goal is to achieve maximum efficiency for all gas consumed. Don't run in EV mode when high power is required (high speeds or up hill), and don't charge the HVB. Don't run the ICE when low power is required (at low speeds or down hill), unless you can also charge the HVB to increase the load on the ICE and can run later in EV mode at low speeds. There are additional considerations when deciding to charge the HVB. The HVB of the Fusion Energi is composed of 84 cells (less for the Fusion Hybrid). The cells need to all be kept balanced, i.e. maintained at the same SOC and voltage. Using power from the HVB tends to disrupt this balance--the greater the power drawn from the HVB and the lower the SOC, the greater the disruption. Charging the HVB restores the balance. The weaker cells experience greater stress than the stronger cells. If the cells are not rebalanced, the weaker cells will continue to experience more stress until they fail. See the following and subsequent posts: "http://www.fordfusionenergiforum.com/topic/1683-obd-ii-data-for-hvb/?p=14915"

FORScan provides the 12 V battery SOC, voltage, amps, and the DC2DC converter High Voltage Power and Low Voltage Power. The BdyCM (BCM) provides the 12 V battery measurements: BAT_CURRENT Vehicle Battery - Current BAT_ST_CHRG Vehicle Battery - State of Charge V_BATT_BCM Battery Voltage The DCDC provides the power measurements (multiply current by voltage to get power in watts): High Voltage side ConvHiCurre DC/DC Converter High Voltage (HV) Current - Measured HEV_Hi_VOL Hybrid Electric Vehicle (HEV) High Voltage Bus - Measured Low Voltage side ConvLoCurre DC/DC Converter Low Voltage (LV) current ECU_Pow_Supp Module Supply Voltage I'm not sure that the Load Shed Control DTC is very useful. I think that is more informational than indicating there is a problem. I see it all the time. It would be nice if you could record data while the car was off--but the ECU needs to be running to read any PIDs.

It has now been a month since TSB 14-0020 was applied. This past week, the SOC of the 12 V battery, as reported by the BCM, has been between 89 and 91% when I check in the morning. After resting for about three hours, I measure the voltage to be around 12.85 V. Prior to the TSB, the SOC averaged around 70% and the resting voltage was more like 12.55 V. So the TSB definitely changed how the battery is charged and maintained, and probably also strengthened the battery. Over the month, the charging voltage has gradually reduced from 14.7 V to about 14.3 V now. The charging algorithm and battery are both adapting--I am not sure what is happening. Hopefully it is for the better. I'm not sure how this TSB would apply to the Fusion Hybrid though. I have the Fusion Energi, so when I leave the car plugged into the charger, the car can charge the 12 V battery anytime it wants and it seems to want to do it a lot this past month.

When replacing the battery, the service personnel can tell the BCM (Body Control Module) that the battery has been replaced and what type it is. However, there are only a few limited types that is recognizes: - 4 - AGM 80Ah 700CCA T7 Case - 5 - AGM 70Ah 600CCA H6 Case - 6 - AGM 80Ah 700CCA H7 Case - 7 - Varta 43Ah 390CCA T4 Case - 8 - Varta 52Ah 500CCA T5 Case - 9 - Varta 60Ah 590CCA T6 Case - 10 - Varta 80Ah 700CCA17 Case - 11 - Varta 90h 800CCAT8 Case - 12 - Varta 60Ah 520CCA H5 Case - 13 - Varta 70Ah 600CCA H6 Case - 14 - Varta 80Ah 700CCA H7 Case - 15 - Varta 90h 800CCA H8 Case - 16 - Varta 90h 950CCA HB Case - 17 - Exide 43Ah 390CCA T4 Case - 18 - Exide 52Ah 500CCA T5 Case - 19 - Exide 60Ah 590CCA T6 Case - 20 - Exide 80Ah 700CCA T7 Case - 21 - Exide 90Ah 800CCA TB Case - 22 - Exide 60Ah 520CCA H5 Case - 23 - Exide 70Ah 600CCA H6 Case - 24 - Exide 80Ah 700CCA H7 Case - 25 - Exide 90Ah 800CCA H8 Case - 26 - Exide 90Ah 950CCA HB Case