OBD II Data for HVB

[larryh]

I wonder how the car maintains constant load and rpms on the ICE regardless of the speed and power demands that I place on the car.  Can it adjust the transmission almost instantaneously to changes in power and speed to maintain a constant ICE operating point of 1500 rpm and 65% load?  Or rather than directly providing torque to the wheels, is it simply running the generator at that constant speed and load to provide a fixed amount of power for the electric motor to propel the vehicle.  The remaining power required comes from the HVB. 

I updated post #24 above in an attempt to answer these questions.  I add the motor and generator inverter temperatures to the plot.

Edited January 26, 2014 at 11:07 AM by larryh

[Hybridbear]

I'm going to guess that because the HVB temperature is only 23 F, it can no longer provide 7.6 kWh of energy.  That might explain the discrepancy.  The EV range is currently 16 miles, far less than the normal 25 miles in summer. 

The FFH limits use of the HVB when it's very cold. It also takes more kW out of the battery to get the same amount of kinetic energy from a moving vehicle. I drove a short trip in my parents' C-Max Energi on Saturday which in temperate weather would get 150+ MPGe. On Saturday I had preconditioned the car so it was moderately warm when I got in and I didn't use the electric heat at all, only heated seats. The HVB temp was less than 15F at the start of my trip. The trips on Saturday returned less than 110 MPGe. The HVB is definitely less efficient when cold. I'm curious if the Energi also uses the fans to move warm cabin air over the battery when it is cold in the winter like the hybrid does.

When the HVB is extremely cold your EV power is limited. While the dealer fixed the trunk on our new white FFH today they gave me our old black FFH to drive. The HVB temp when I left the dealer was 4.5 F according to the ScanGauge. The HVB would not run the car in EV mode at all. Any touch of the gas pedal would make the ICE come on. I didn't think to get a pic showing the 0 threshold. Once the HVB warmed up above 15F I was able to get 1/2 bar of EV as shown in the pic below. Once the HVB hit 20F I was able to get 1 bar of EV. I did not get normal EV operation back until the HVB was warmer than 32F. The HVB fans came on right away and ran non-stop to funnel heated cabin air across the HVB.

http://fordfusionhybridforum.com/topic/7492-understanding-the-ffh-better-with-a-scangauge/?p=74042

 

I wonder how the car maintains constant load and rpms on the ICE regardless of the speed and power demands that I place on the car.  Can it adjust the transmission almost instantaneously to changes in power and speed to maintain a constant ICE operating point of 1500 rpm and 65% load?  Or rather than directly providing torque to the wheels, is it simply running the generator at that constant speed and load to provide a fixed amount of power for the electric motor to propel the vehicle.  The remaining power required comes from the HVB. 

The hybrid never does this. The C-Max Energi also acts this way. This is much less efficient that running under a high load. This is part of why the Energi is less efficient in "hybrid" mode than the hybrid. The FFH rarely runs the ICE without using it to spin the generator and charge the HVB. A 100% score on the acceleration coach bar requires you to accelerate the first little bit in EV and then kick the ICE on and accelerate at 2 bars or so. At this level of acceleration the ICE runs at about 40 HP and 90+ LOD. If you slightly depress the pedal more, the ICE will not increase the LOD or HP, but will just charge the HVB less. If you slightly back off on the pedal, the ICE will charge the HVB more, up to ~20 amps @ ~300 volts (~6 kW) flowing into the battery. Regen braking seems to peak at ~50 amps @ ~300 volts (~15 kW) flowing into the HVB. The ICE will not charge the HVB from the generator faster than ~20 amps, but will begin to reduce the output of the ICE. The "favorite" charge rate of the ICE seems to be ~15-16 amps (~4.5-4.8 kW) flowing into the HVB. Between 36-42 HP the ICE LOD is consistently 90+. This is also the HP range in which the computer likes to operate the ICE. Your BSFC will be higher at 1500 RPM & 65 LOD than at ~2000-2300 RPM (36-42 HP) & 90+ LOD. A C-Max Hybrid owner has found that 2000 RPM seems to be a really efficient RPM for the ICE in these cars.

 

The Energi likes to use the electricity in the HVB even if you're in "EV Later". It doesn't like to use the ICE to charge the HVB until the HVB is depleted, then it runs very similar to the FFH & C-Max Hybrid, using the ICE to charge the HVB and then running in EV for brief stretches to discharge the HVB. In driving my parents' C-Max on a few longer trips, I found that it is more efficient running in "hybrid" mode with the HVB depleted than it is running in "hybrid" mode by pushing EV Later.

[larryh]

The Energi also limits HVB power when its cold.  This afternoon, after sitting outside in the cold (it only got up to -6 F today), the HVB temperature was 9 F.  The Empower display showed the ICE turn on threshold to be 25 kW.  It is normally 40 kW.  I'm not sure what units each tick mark corresponds to in the FFH, but 25 kW is 2.5 bars on the Energi.  The HVB can't generate as much power when the battery is cold.  I don't think the MPGe will vary based on the HVB temperature.  The reason you get low MPGe when it is cold, is because it takes 30% more energy to propel the car.  The rolling resistance of the tires increases significantly, air density is much higher, and the viscosity of the fluids increase causing more friction.  See http://www.fordfusionenergiforum.com/topic/1446-cold-weather-observations/?p=10616.

[larryh]

I believe that the purpose of running the ICE at a constant 1500 rpm is to solely to warm up the engine.  The car's primary goal is to still run in EV mode.  However, it has to run the ICE intermittently to keep the engine warm.  It will run the ICE even if the car is not moving until the coolant heats up to around 110 F.  If the ICE has the opportunity to supply some of its power to the generator to provide electricity to the electric motor, then so much the better for efficiency.   The electric motor is probably around 95% efficient in powering the car using electricity.   The ICE is more efficient at higher loads and lower RPMs.  So running the generator and placing a load on the ICE allows the ICE to run more efficiently and the electricity generated is then used efficiently to power the car.  It obviously takes more gas, but it generates more power which can be utilized effectively for each quantity of gas consumed up to loads of 65% from the previous graphs.  It probably would be better to apply the ICE's power directly to the wheels, but then the car would not have as much control over the RPMs and load placed on the ICE and it would most likely use far more gas than if it only opportunistically runs the generator, contrary to the car's primary goal of trying to run in EV mode and use minimal gas. 

 

If you stop at a stop light or decelerate resulting in regen, the load on the ICE is reduced.  It does not appear run the generator to charge the battery, probably because the battery is so cold, it takes too much energy to charge the battery for the extra gas that needs to be consumed to generate that electricity. 

 

This morning, my 8 mile commute to work at -15 F took 0.05 gallons of gas (with preconditioning of the car).  The 8 mile commute home (car sat out in the cold) at -6 F consumed 0.13 gallons of gas.  Few cars can match that.  Note that the Energi supplies far more than 50 amps of current to the HVB during regenerative braking, up to about 2.5 times that amount. 

Edited January 28, 2014 at 09:56 AM by larryh

[Hybridbear]

The Energi also limits HVB power when its cold.  This afternoon, after sitting outside in the cold (it only got up to -6 F today), the HVB temperature was 9 F.  The Empower display showed the ICE turn on threshold to be 25 kW.  It is normally 40 kW.  I'm not sure what units each tick mark corresponds to in the FFH, but 25 kW is 2.5 bars on the Energi.  The HVB can't generate as much power when the battery is cold.  I don't think the MPGe will vary based on the HVB temperature.  The reason you get low MPGe when it is cold, is because it takes 30% more energy to propel the car.  The rolling resistance of the tires increases significantly, air density is much higher, and the viscosity of the fluids increase causing more friction.  See http://www.fordfusionenergiforum.com/topic/1446-cold-weather-observations/?p=10616.

The tick marks should represent about the same power demand in the hybrid as well. Interesting to see how the Energi limits the battery use as well.

 

I believe that the purpose of running the ICE at a constant 1500 rpm is to solely to warm up the engine.  The car's primary goal is to still run in EV mode.  However, it has to run the ICE intermittently to keep the engine warm.  It will run the ICE even if the car is not moving until the coolant heats up to around 110 F.  If the ICE has the opportunity to supply some of its power to the generator to provide electricity to the electric motor, then so much the better for efficiency.   The electric motor is probably around 95% efficient in powering the car using electricity.   The ICE is more efficient at higher loads and lower RPMs.  So running the generator and placing a load on the ICE allows the ICE to run more efficiently and the electricity generated is then used efficiently to power the car.  It obviously takes more gas, but it generates more power which can be utilized effectively for each quantity of gas consumed up to loads of 65% from the previous graphs.  It probably would be better to apply the ICE's power directly to the wheels, but then the car would not have as much control over the RPMs and load placed on the ICE and it would most likely use far more gas than if it only opportunistically runs the generator, contrary to the car's primary goal of trying to run in EV mode and use minimal gas. 

 

If you stop at a stop light or decelerate resulting in regen, the load on the ICE is reduced.  It does not appear run the generator to charge the battery, probably because the battery is so cold, it takes too much energy to charge the battery for the extra gas that needs to be consumed to generate that electricity. 

 

This morning, my 8 mile commute to work at -15 F took 0.05 gallons of gas (with preconditioning of the car).  The 8 mile commute home (car sat out in the cold) at -6 F consumed 0.13 gallons of gas.  Few cars can match that.  Note that the Energi supplies far more than 50 amps of current to the HVB during regenerative braking, up to about 2.5 times that amount. 

You're correct that it runs the ICE at that low RPM for warm up. It's also for emissions reasons. EPA tests for emissions lead manufacturers to do things that lead to less real world fuel economy but better EPA emissions scores.

 

What peak current from regen braking have you seen in the Energi? I've seen it do more than 50 amps, but it's hard to watch the ScanGauge & the road when driving. The higher your speed when braking the higher the amps going into the HVB because there's more potential energy. I've seen the Prius hit 80 amps going into the HVB but the Prius pack is less volts (~220) so 80 amps in it isn't as many kW as 80 amps in the FFH or FFE. The Energi pack is also higher voltage than the FFH pack so it will have lower amps for the same kW.

[larryh]

The HVB voltage is around 340 volts when fully charged.  The maximum current I have observed for regenerative braking so far is 115 amps.  I'm not sure what it would be if the HVB were at its peak operating temperature rather than in the 40s.  Also, I am not exactly sure what the units are on the tick marks for the different displays.  But I think they are generally around 10 kW.  I received a reply from Ashley regarding them here:  http://www.fordfusionenergiforum.com/topic/782-uom-used-for-information-displays/?p=10959.

[Hybridbear]

The HVB voltage is around 340 volts when fully charged.  The maximum current I have observed for regenerative braking so far is 115 amps.  I'm not sure what it would be if the HVB were at its peak operating temperature rather than in the 40s.  Also, I am not exactly sure what the units are on the tick marks for the different displays.  But I think they are generally around 10 kW.  I received a reply from Ashley regarding them here:  http://www.fordfusionenergiforum.com/topic/782-uom-used-for-information-displays/?p=10959.

According to the ScanGauge, accelerating at 2 bars on Empower is 41HP, 1 bar is 20 HP (with a varying amount of amps going back into the battery). This means that each tick is about 15 kW. In EV mode, 1 bar acceleration is 22-23 amps @ 290 volts or 6.38-6.67 kW.

[larryh]

The following graph is for same 8 mile trip as in post 24 above.  I have added torque from the ICE to the plot.  I am guessing that this shows the amount of force applied directly to the wheels from the ICE.  It drops to zero when the ICE is off, and during braking and coasting.  It spikes during acceleration. 

 

When the ICE is on, the ICE maintains a constant 1500 rpm and a relatively constant load of around 65% (except when stopped, braking, or coasting).  While doing that, you can see spikes in the torque applied to the wheels by the ICE.  So it appears to be doing a balancing act in the positive split propulsion mode of operation, where power from the ICE is split between the direct path to the road and the path through the generator, to maintain constant rpm and load.

 

Edited January 29, 2014 at 10:57 PM by larryh

[larryh]

The Energi likes to use the electricity in the HVB even if you're in "EV Later". It doesn't like to use the ICE to charge the HVB until the HVB is depleted, then it runs very similar to the FFH & C-Max Hybrid, using the ICE to charge the HVB and then running in EV for brief stretches to discharge the HVB. In driving my parents' C-Max on a few longer trips, I found that it is more efficient running in "hybrid" mode with the HVB depleted than it is running in "hybrid" mode by pushing EV Later.

When running in EV Later mode today on the Freeway at a constant 65 mph, I observed the ICE rpm to be constant at 2075 rpm with a constant 68% load.  The SOC of the HVB remained constant.  There was very little charging or discharging of the HVB.  This was for 10 miles at about 3 F.   There were no EV miles for this section of the trip.  So it was purely the ICE powering the car during this interval--no plug-in energy was used.  The MPG was 37.   I think this behavior is different in the summer time, i.e. the SOC of the HVB varies, there are EV miles, and the mileage would be about 44 MPGe.  I will have see what happens after the HVB is depleted. 

Edited February 1, 2014 at 09:44 PM by larryh

[larryh]

The following shows the Engine Map computed from the OBD II data for the 60 mile commute at 3 F in the previous post #34.  I used ICE RPM, % Load, and Fuel Consumption (gallons/minute) data during the trip to compute the chart.  The chart is a crude approximation.  I don't have enough data to make an accurate map and the data is not all that reliable.  For instance, the values of RPM, Load, and fuel consumption are, in general, not synchronized.  They are computed at different times.  So if I am using data from a time when the ICE is changing RPMs or Load is changing, then the data is suspect.  Along the x axis is ICE RPM from 1750 RPM to 2450 RPM.  Along the y axis is % Load on the ICE from 65% to 85%.  I suspect this is relative load so the chart is distorted.  The maximum torque that can be produced by the ICE varies with RPM.   This chart assumes it does not vary with RPM.  I am using % Load as a proxy for torque. 

 

I simply computed efficiency as RPM * Load / fuel consumption.  RPM * Load is proportional to power.  So the higher the efficiency, the more power the ICE is generating per quantity of fuel consumption.  The car was operating at a constant 2075 rpm and a constant 67.7% load when going 65 mph.  This is indicated by the black circle on the map.  The car did not appear to be running the generator, so there was no additional load on the ICE other than for propelling the car.  In order to provide sufficient power to 65 mph, the ICE has to operate somewhere on the black line. 

 

It looks to me like it is selected a good efficient operating point.  If the RPMs were much lower, then efficiency would decrease, i.e. deeper into the purple colored region or one of the other less efficient colored regions (green, red, or darker blue).  Faster RPMs may look more efficient on this chart, but the chart is not all that accurate, so I cannot conclude that it would actually be more accurate to operate at higher RPMs.  Adding additional load to the ICE would decrease efficiency (the operating point would move up along the y-axis further into the purple, green, red, or darker blue regions), so that could explain why the ICE is not charging the HVB battery.  So I suspect the car is doing what it is supposed to do and run the ICE at its most efficient operating point for the power required. 

 

Edited February 1, 2014 at 10:14 PM by larryh

[larryh]

The following chart shows the maximum power output from the HVB (Maximum Discharge Power Limit) vs. HVB Temperature.  The HVB appears to be able to provide a maximum output of 35 kW at 30 F and above.  When the HVB temperature is below 0 F, it can't provide much power (probably less than 6 kW).  So if the HVB gets too cold, the ICE is going to have to run to provide the power.

 

Edited February 3, 2014 at 01:21 AM by larryh

[tseibel76]

Great info larryh!  This substantiates our earlier observations that a major factor in when the ICE fires is how long the car has been sitting out in the cold.  The longer it sits out, the colder the HVB gets, thus limiting how much power it can provide.  I have noticed a substantial jump in range once you get above 32F.  I try and park in the sun at work as much as possible to keep the HVB warm.  I don't know if it helps or not, but it seems to.

[larryh]

They should provide a battery heater to warm up the HVB while preconditioning the car.   In lieu of that, the Sun works well.

Edited February 4, 2014 at 10:51 AM by larryh

[tseibel76]

A battery heater would be nice.  It's funny they wouldn't have incorporated something into the car given the preconditioning capabilities.  Especially since HVB temp seems to have such a large impact on how often the ICE must come on.

[larryh]

When running in EV Later mode today on the Freeway at a constant 65 mph, I observed the ICE rpm to be constant at 2075 rpm with a constant 68% load.  The SOC of the HVB remained constant.  There was very little charging or discharging of the HVB.  This was for 10 miles at about 3 F.   There were no EV miles for this section of the trip.  So it was purely the ICE powering the car during this interval--no plug-in energy was used.  The MPG was 37.   I think this behavior is different in the summer time, i.e. the SOC of the HVB varies, there are EV miles, and the mileage would be about 44 MPGe.  I will have see what happens after the HVB is depleted. 

Today, driving in hybrid mode on the freeway at a constant 65 mph, I observed the ICE rpm to be a constant 2090 rpm with a constant 69% load.  Again, the SOC of the HVB remained constant and there was very little charging or discharging of the HVB.  The temperature was -3 F.  So it appears to behave the same in EV Later mode as it does in hybrid mode (when the HVB is depleted).  The car was powered entirely by the ICE.  The MPG on the freeway was 39.5. 

Edited February 7, 2014 at 05:31 PM by larryh

[larryh]

Analyzing the data for one of my commutes to work, I observe the SOC of the HVB going from 96.742% to 62.888%.  The trip consumed 2.44 kWh of electricity.  Assuming the capacity of the HVB is 7.6 kWh, consuming 96.742% - 62.888% = 33.854% of the SOC of the battery amounts to 2.57 kWh of electricity.  This suggests that the charge/discharge efficiency of the battery is about 2.44/2.57 = 95%.  The temperature range of the HVB during the commute was from 19.4 F to 35.6 F.  I am unsure what impact temperature has on the HVB capacity and efficiency.  I will have to try this when it is warmer.  It is still -15 F at night lately.

 

When charging the HVB with a 240 V charger, the charging station consumes about 3.4 kW of electricity.   The car supplies only 3.0 kW of that power to the HVB.  I am unsure what the car is doing with the remaining 400 watts.  Assuming a charging efficiency of 95%, then of the 3.0 remaining kW of power, 0.95*3.0 = 2.85 kW is actually stored by the HVB.  Thus the charging efficiency of the HVB is about 2.85 / 3.4 = 83%.  This is very close to what I have actually measured over several weeks of charging, which is 82%.

 

So there is about a 5% loss when charging due to charge/discharge efficiency of the battery, and about 12% loss due to the electronics, fans, power converters, etc. running inside the car. 

[meyersnole]

Analyzing the data for one of my commutes to work, I observe the SOC of the HVB going from 96.742% to 62.888%.  The trip consumed 2.44 kWh of electricity.  Assuming the capacity of the HVB is 7.6 kWh, consuming 96.742% - 62.888% = 33.854% of the SOC of the battery amounts to 2.57 kWh of electricity.  This suggests that the charge/discharge efficiency of the battery is about 2.44/2.57 = 95%.  The temperature range of the HVB during the commute was from 19.4 F to 35.6 F.  I am unsure what impact temperature has on the HVB capacity and efficiency.  I will have to try this when it is warmer.  It is still -15 F at night lately.

 

When charging the HVB with a 240 V charger, the charging station consumes about 3.4 kW of electricity.   The car supplies only 3.0 kW of that power to the HVB.  I am unsure what the car is doing with the remaining 400 watts.  Assuming a charging efficiency of 95%, then of the 3.0 remaining kW of power, 0.95*3.0 = 2.85 kW is actually stored by the HVB.  Thus the charging efficiency of the HVB is about 2.85 / 3.4 = 83%.  This is very close to what I have actually measured over several weeks of charging, which is 82%.

 

So there is about a 5% loss when charging due to charge/discharge efficiency of the battery, and about 12% loss due to the electronics, fans, power converters, etc. running inside the car. 

 

Thanks Larry... always look forward to your analysis. Will be interesting to see how much this changes in the Summer time.

[larryh]

Today I attempted to determine the percent of kinematic energy recaptured through regenerative braking.  I can measure the increase in SOC of the HVB, and assuming the capacity of the HVB is 7.6 kWh, I can measure the increase in energy stored in the HVB through regenerative braking.   I also assume that the car weighs about 4,100 lbs with me and its contents (and the ice on it).  I obtained the following results.  They do not take into account air resistance or rolling resistance of the tires.  The outside temperature was -5 F.

 

HVB Temp (F)    Efficiency (%)

12.2                   0.627278

15.8                   0.650664

17.6                   0.640073

21.2                   0.672613

28.4                   0.725398

33.8                   0.769647

37.4                   0.792488

 

So as the HVB temperature increases, regenerative braking efficiency increases.  The relationship is linear.  In the summer time, regenerative braking should recapture more than 80% of the kinematic energy of the car.  Note that efficiency is actually greater than what is shown, since I don't account for air or rolling resistance.  It takes energy to overcome this resistance and I did not subtract that energy from the kinematic energy. 

Edited March 1, 2014 at 04:34 PM by larryh

[larryh]

This morning, it was -17 F.  The HVB temperature was -6 F.  The maximum charge/discharge power from the HVB at this temperature is 7.5 kW.  See http://www.fordfusionenergiforum.com/topic/1683-obd-ii-data-for-hvb/?p=11084 for values at higher temperatures.  For some reason, the maximum charge/discharge values were higher today than when I previously measured them in the chart in the previous link.  At a HVB temperature of 3.2 F, previously the maximum charge/discharge value was between 10.25 and 12.25 kW.   This time it was between 16.5 and 18.5, or about 6 kW higher. 

Edited March 2, 2014 at 05:09 PM by larryh

[larryh]

The following chart shows the OBD II data from a short drive when the outside temperature is -10 F.  The overnight temperature dropped to -17 F.  The HVB temperature started out at -6 F and rose to 12 F.  The estimated range was 12 miles with climate off and 9 miles with climate on.  The ICE started immediately when I turned on the car.  As is always the case when it is this cold, I had to use the backup slot in the car to start it.  The Intelligent Access Key does not work properly for me when it is this cold. 

 

The ICE ran at a constant 1500 rpm and at mostly around 60% load, reaching 90% during acceleration and falling to 35% when stopped. It ran until the coolant temperature reached about 100 F.  The car seems to ignore the Maximum Discharge Power Limit from the HVB, i.e. the red line is above the purple line in several places.  This probably because I had it in EV Now mode, which apparently overrides the limit.  However, it does not ignore the Maximum Charge Power Limit for the HVB, i.e. the red line stays above the dark blue line.  So regenerative braking is limited when the HVB is cold.  You have to apply the brakes far more gently when the HVB temperature is -6 F than when the HVB is warm to recapture the maximum possible kinetic energy while braking.  At least the battery seems to warm up quickly.  In ten minutes, the Maximum Charge/Discharge Power Limit is about at its maximum value of 35 kW, which occurs when the HVB temperature is above 32 F.

 

Edited March 2, 2014 at 06:07 PM by larryh

[larryh]

When charging the HVB with a 240 V charger, the charging station consumes about 3.4 kW of electricity.   The car supplies only 3.0 kW of that power to the HVB.  I am unsure what the car is doing with the remaining 400 watts.  Assuming a charging efficiency of 95%, then of the 3.0 remaining kW of power, 0.95*3.0 = 2.85 kW is actually stored by the HVB.  Thus the charging efficiency of the HVB is about 2.85 / 3.4 = 83%.  This is very close to what I have actually measured over several weeks of charging, which is 82%.

 

So there is about a 5% loss when charging due to charge/discharge efficiency of the battery, and about 12% loss due to the electronics, fans, power converters, etc. running inside the car. 

 

I am now able to account for the energy used to charge the car with a Level 2 charger.  The charger inside the car consumes 14 amps of electricity at 240 V, which is 3360 Watts of power.  The on-board electronics and fans required to power the charger in the car consume about 65 Watts of power.  So the car consumes a total of about 3425 Watts of power from a Level 2 charging station.  The charger inside the car outputs about 10 amps at 300 volts, or 3000 Watts.  So the charger inside the car looses 360 watts of power converting AC to DC, or is about 90% efficient.  Of the total 3425 Watts of power consumed from the Level 2 charging station, only 3000 Watts makes it to the HVB, a total loss of about 12.5%.  However, the HVB is not 100% efficient in storing energy.  I have measured the overall charging efficiency of the battery to be around 82%, i.e. for every kWh of electricity consumed from a Level 2 charging station to charge the battery, you can extract 0.82 kWh of energy from the battery.  That means the efficiency of the battery itself is 94%, you get 94% of the energy out that you put into it. 

Edited March 31, 2014 at 09:19 PM by larryh

[Bills_Fusion_Energi]

Larryh:

 

I’ve watched my 120v charging (using the charger that comes with the vehicle) and data collected from the Linear Logic Scan Gauge:

 

During the charge times that I’ve watched (between 24% thru 98%) I see the HBC (High Voltage Battery Current) varying “every few minutes” between -1.59 (minimum) to -1.82 (maximum) with the temperature only varying from 85 to 87 (HBT) and the Voltage (HBV) varying from 318 to 327.

 

MY REAL concern is the comparison between the 120v AC wattage and the High Voltage Battery Wattage (Volts X Amps) while charging.

 

I’ve obviously watched my AC wattage MORE since I’ve only had the Scan Gauge for a few days but the 120v AC wattage varies between 1359 to 1374 watts and it also changes “every few minutes” and rarely goes above or below those values during MOST of the charge cycle.

 

When I compute the High Voltage Battery Wattage is shows a min of 513 watts and a max of 587 watts. SO, “what is happening to the MISSING wattage 784 to 846 watts?”

 

I realize that there are losses in the AC to DC converter in the vehicle and that not all of the wattage is being used to charge the High Voltage Battery, some of it is used to power the electronics on the vehicle and some (approx 60 watts) is used to charge the Low Voltage (12v) battery, as you have indicated in YOUR posts.

 

I would expect the HBC to be above -4.0 amps to even get close to the AC wattage so what are your thoughts in this area?

 

Bill

[larryh]

I don't have a Scan Gauge, so I am not quite sure what you are measuring.  This is what I see for the 120 V charger that came with the car.

 

Kill-A-Watt meter shows 11.55 amps at 115 V = 1330 Watts.

Input to charger in car is 11 amps at 111.4 V = 1225 Watts.

Output from charger in car 3.4 amps at 296.5 V = 1000 Watts.

Input to HVB is 3.4 amps at 296.5 V = 1000 Watts.

 

The electronics and fans in the car are using about 1330 - 1225 = 105 Watts

The charger is losing 225 Watts converting ac to dc, or 82% efficient (significantly less efficient than the 240 V charger).

 

I see only minor fluctuations in these values.  I would verify the Scan Gauge codes for reading current flowing into the HVB. 

Edited April 2, 2014 at 12:02 AM by larryh

[larryh]

It appears that the HVB charges to 99% SOC with about 7.0 kWh of energy.  When the SOC reaches about 21.5% with 1.5 kWh of energy, the car switches to showing the hybrid battery display.  When the SOC reaches about 14.5% with 1.0 kWh of energy, the ICE turns on.  Thus the maximum plug-in energy available from the car is approximately 7.0 - 1.0 = 6.0 kWh.  The car does not appear to charge the HVB to the maximum capacity of 7.6 kWh nor discharge it below 1.0 kWh. 

Edited April 2, 2014 at 09:03 AM by larryh

[larryh]

Looking at the car's estimated energy stored in the HVB vs. the amount of energy applied to the HVB by the charger inside the car, it looks like the HVB stores 97.3% of the energy applied to it. Discharging is also 97.3% efficient. The overall battery efficiency is 97.3%*97.3% = 94.7% efficient. This is close to the previous estimate of 94% efficiency. You get about 94-95% of the energy out of the battery that is put into it.

Edited April 14, 2014 at 12:45 PM by larryh