Understanding the FFH better with a ScanGauge

[lolder]

Very cool! So...

 

280 volts x 20 amps = 5600 watts = 5.6 kW = 7.51 hp. This makes sense that the first line on the Empower screen would be about 7.5 hp considering that when the ICE is running at that line it typically shows about 21-23 hp with about 16-18 amps flowing into the battery. When idling with the ICE on I've determined that 14-15 hp from the ICE gets about 16-18 amps of charge flowing into the battery. So if we take away the 14-15 horsepower for the generator we're left with about 7.5 horsepower left to power the car. Very cool!!

 

Thank you for the reminder of how it works.

 

The max charging I've observed is just over 40 amps. The max discharging I've observed is just over 50 amps.

The HVB can peak for 1 second at over 120 amps discharge ( 34 kw at 270 V. ) and about 90 ( 25 kw ) charge in the Gen I FFH. See table 2 here: http://avt.inl.gov/pdf/hev/batteryfusion4757.pdf.

50 amps is reasonable to see in normal driving.

I would expect the LiIon of the Gen II FFH to be more powerful.

Edited September 13, 2013 by lolder

[corncobs]

Here's a question for everyone, any ideas of how to secure the cable? I used the velcro mounts to mount the SGII on the steering column behind the wheel but in front of the dash. In this location it doesn't block any of the dash and is completely visible behind the steering wheel. However, there is a lot of extra cable. Any ideas of how to best secure the extra cable? Thanks.

Hi HB have you thought about cable tie holders? They come in different sizes and should help secure the cable. I used them inside the center console securing the wires for my ambient lighting.

Any extra wire I would hide behind the steering column right where the fuses are.

 

[vangonebuy]

Any ideas of how to best secure the extra cable?

 

 

A long wire twist tie works well.

Wrap the excess SGII wire into a bowtie.

Wrapping the twist tie wire across the middle and tightening.

Then, with the excess twist tie wire. Attach it to the wire harness underneath the dash.

 

That way you can remove it without undoing the bowtied wire.

Be careful of the SGII connectors in the back. The clip in square plastic piece is not held in too well.

So leave some slack in the wire.

I know.

 

SGII is very handy for running a Trouble code scan on others car. I take it out often.

 

If you ever get rich, A second SGII can be daisy chained off the 1st one.

Giving you 8 readouts at once.

 

[hybridbear]

Thanks for the ideas. I researched in general on the internet about this and found suggestions on other Forums about sliding the excess cable inside the steering column where there's a space at the bottom so that's what I did. If anyone knows of something that might be damaged by doing this, please let me know. Otherwise that's where the cable is for now.

[acdii]

Thanks for the ideas. I researched in general on the internet about this and found suggestions on other Forums about sliding the excess cable inside the steering column where there's a space at the bottom so that's what I did. If anyone knows of something that might be damaged by doing this, please let me know. Otherwise that's where the cable is for now.

Now that you mention this, thats what I did too.

[hybridbear]

Another observation: some of you have noticed that your car will sound like the ICE is pulsing. The pressure on the pedal is constant but you'll hear the sound of the ICE change. With the SGII I've been able to see that when you hear that pulsing noise the RPM isn't changing much, but the horsepower increases and decreases and the LOD also goes up and down with the sound. The change in LOD is triggered by an increasing and decreasing generator load. When the LOD and HP go up the amps going into the battery also increase.

Just another interesting tidbit I've noticed with the SGII.

Edited September 18, 2013 by hybridbear

[hybridbear]

Here is some more information to go with my notes about air conditioning use from the initial post. I commented there that the AC draw is about 15 amps, maybe as high as 20 when you're first starting out with a hot car. Based on an average HVB voltage of about 285 that would mean the AC is drawing 285 x 15 = 4275 watts or 4.275 kW. When I've observed the AC drawing this level of current the MyView display shows the AC draw at about 4.275 bars. This leads me to believe that on that screen each bar equals 1 kW of power draw.

 

When the car is cool the AC current draw drops to about 2 amps. 2 x 285 = .57 kW. This jives with that graph displaying about a half bar sustained power demand to run the AC.

 

Considering that the current draw at idle is about .6 amps times 285 volts or .17 kW that seems to mesh with the display showing just under 1/4 of a bar for the accessories functions.

[acdii]

Yep, for once a car display thats accurate, at least they got that part down! :)

[hybridbear]

Here are some more voltage observations...

 

Ford calls the HVB systems approximately 300 volts DC. I've observed with the SGII that when the battery SOC is higher the pack voltage is higher. When the SOC is being charged the pack voltage increased up to about 295+ volts. When being discharged the pack voltage has dropped down under 280 with a low SOC. This means that the AMPs of current flow equal different kW values based on pack voltage. The numbers that we've previously discussed for kWs at certain amperage levels are based on approximations. It's interesting to see how much the pack voltage varies.

 

I'm not sure what this all means because I'm not an electrical engineer. However, learning about this car sure makes me wish I had picked electrical engineering as my major in college instead of Risk Management/Finance. If I were graduating High School today and deciding on a major I would definitely choose some form of engineering...

Edited September 30, 2013 by hybridbear

[acdii]

With Lion cells, the peak voltage is ~4.2v, max discharge, the never exceed this voltage or kiss the battery goodbye is 2.5-3v. The nominal voltage is 3.8v. This is the voltage the cells will stay at during discharge until they are depleted. Its a fairly flat curve from peak to discharged.

 

Based on your readings, and the voltages per cell, there would mean there are 75 cells in the pack, and low cutoff is programmed at 3,73 v per cell. Thats does sound about right. While my LiPo packs have a slighty greater range, 3.2-4.2, storage at 3.8 v, the lion is very similar.

 

My guess on the charge/discharge levels is 4.1 peak and 3.6 cutoff. The system will not let you get below a set voltage no matter what, it will shut itself down if that ever happens. It will also not go above a set voltage per cell. I can almost guarantee that the battery pack has each cell wired to a master control board that prevents any one cell from going above or below a set voltage, especially on discharge, one a Lixx cell drops below a certain voltage, it will not recover. Over charging a cell can cause it to over heat and that is a very bad thing(just ask Boeing).

[hybridbear]

I recently found on the C-Max Forum XGauge codes for SOC which show that the car only uses a range from about 40%-65% SOC of the HVB. 40% approximately equals an empty battery on the dash and 65% about equals a full dash battery. The dash battery graph doesn't follow a linear scale though. If very quickly moves from about 2/3 full to 1/3 on the display while the HVB actually isn't changing in SOC that much. Another XGauge code allows you to see SoC as the % SoC of the useable portion of the battery. This allows you to see that the battery icon doesn't follow a linear scale. The SoC (SOC = % charge of entire pack ranging from about 40-65%, SoC = % charge of useable portion of battery, coincides with dash display) doesn't change that much when the battery icon shows a big change from about 2/3 full to 1/3 full. This helps to explain why pre-PCM update when on the freeway exceeding 62 MPH it would take so long to get to ICE High mode with high instant MPGs. While the battery icon on the dash would quickly show 2/3 full it would take a long time to reach the approximately 80% full at which point the ICE would stop charging the battery and begin showing high instant MPGs.

 

Unfortunately I haven't had a lot of time driving the car since learning these XGauge codes I don't have a very complete understanding of their relationship. The comments above are my preliminary observations which confirm the observations of some C-Max Hybrid owners who have ScanGauges as well. In future weeks I'll monitor this further and share what else I learn.

[acdii]

Compare SOC with actual battery voltage too. It takes along time to go from 3.8V to 4.2 on a Lipo, so I cant see it being much different for the Lion. I do have a pair of Lion packs for my giant scale, but I haven't flown it yet to get an idea of the voltage levels.

 

Lion, Lipo, and LiFe batteries are similar in how they function, but have different voltages, and different current draws. I Lipo can give a high rate of current, for a short period of time, or a long duration at a slow rate, the Lion is nearly the same, but not as high a current draw, and has a lower voltage. LiFe is mainly for slow draw long duration applications, such as radios, and low current motors. It also operates at a different voltage. It also cant be charged at a high rate like the Lion and Lipo.

 

Lipos, though they can take and give a high current rate, also can go bad quickly if they get too hot, go above their max voltage, or go below their cutoff voltage, where the Lion is more stable in voltage ranges, and can recover if they go below their cutoff voltage.

 

I believe this to be the reason for the use of Lion instead of Lipo in the Ford. So based on what I know of cell voltages and current draw, the HVB in the Fusion will be between a set voltage range based on the SOC readings you see. What you haven't found yet is the amps used and recovered, and that will tell you a lot more about the batteries than SOC and voltages. What is the capacity of the pack and how much energy is consumed to bring up to its capacity.

 

An example of this would be, when I recharge a LiPo after an 8 minute flight, at the end of the charge cycle the charger tells me how many mah was put back into the battery. The battery is rated at 3300 mah, so at 8 minutes of flight time I used 2700 mah that was restored to the battery, leaving me 600 mah of reserve. You never ever want to use all the mah, as it will harm the battery. So knowing the capacity of the pack, the number of cells, and the cutoff voltages would help determine just how much energy the pack and give and take. This helps me with setting a timer as the get it down now alert. Also based on the low voltage reading before charge and mah restored at end of charge will give me an idea of the condition of the battery.

 

This I believe is the most important piece! If a pack rated at 3300 mah, cuts off at 3.4 volts, and recharges at only 2200 mah, the pack is weak and needs to be replaced. At that voltage it should be able to take at least 2700 or more mah. Seeing how many amps are used and how many are put back in the HVB will tell us what the actual pack condition is, but knowing what it is rated at is what we dont have, and need to know that before being able to know what its condition is.

 

So for someone like MXGOLF who has not been able to get good MPG, and feels the pack is the problem, being able to determine its actual capacity would tell us if the pack is the issue or not.

[hybridbear]

Compare SOC with actual battery voltage too. It takes along time to go from 3.8V to 4.2 on a Lipo, so I cant see it being much different for the Lion. I do have a pair of Lion packs for my giant scale, but I haven't flown it yet to get an idea of the voltage levels.

 

Lion, Lipo, and LiFe batteries are similar in how they function, but have different voltages, and different current draws. I Lipo can give a high rate of current, for a short period of time, or a long duration at a slow rate, the Lion is nearly the same, but not as high a current draw, and has a lower voltage. LiFe is mainly for slow draw long duration applications, such as radios, and low current motors. It also operates at a different voltage. It also cant be charged at a high rate like the Lion and Lipo.

 

Lipos, though they can take and give a high current rate, also can go bad quickly if they get too hot, go above their max voltage, or go below their cutoff voltage, where the Lion is more stable in voltage ranges, and can recover if they go below their cutoff voltage.

 

I believe this to be the reason for the use of Lion instead of Lipo in the Ford. So based on what I know of cell voltages and current draw, the HVB in the Fusion will be between a set voltage range based on the SOC readings you see. What you haven't found yet is the amps used and recovered, and that will tell you a lot more about the batteries than SOC and voltages. What is the capacity of the pack and how much energy is consumed to bring up to its capacity.

 

An example of this would be, when I recharge a LiPo after an 8 minute flight, at the end of the charge cycle the charger tells me how many mah was put back into the battery. The battery is rated at 3300 mah, so at 8 minutes of flight time I used 2700 mah that was restored to the battery, leaving me 600 mah of reserve. You never ever want to use all the mah, as it will harm the battery. So knowing the capacity of the pack, the number of cells, and the cutoff voltages would help determine just how much energy the pack and give and take. This helps me with setting a timer as the get it down now alert. Also based on the low voltage reading before charge and mah restored at end of charge will give me an idea of the condition of the battery.

 

This I believe is the most important piece! If a pack rated at 3300 mah, cuts off at 3.4 volts, and recharges at only 2200 mah, the pack is weak and needs to be replaced. At that voltage it should be able to take at least 2700 or more mah. Seeing how many amps are used and how many are put back in the HVB will tell us what the actual pack condition is, but knowing what it is rated at is what we dont have, and need to know that before being able to know what its condition is.

 

So for someone like MXGOLF who has not been able to get good MPG, and feels the pack is the problem, being able to determine its actual capacity would tell us if the pack is the issue or not.

How can I figure this out?

[acdii]

How can I figure this out?

Thats the $64 question. Not sure how you can do it with the scan gauge. Heck I wonder if the fancy $40K laptop Ford uses can do it. Because of the complicated duty cycles, it would need a computer to capture the swings and analyze the trends to see just how much current was used, and energy restored.

[hybridbear]

Based on the efforts of alpha & majorleeslow to do regression equations on fuel economy data I've begun some data gathering of my own. For each trip in the FFH I am tracking the following data points: beginning coolant temp, beginning useable SOC (i.e. how full is the battery icon), beginning overall SOC (i.e. current % charge of total battery), ending useable SOC, ending overall SOC, trip miles, EV miles, regen miles, brake score %, outside temp, HVAC use.

 

So far I have just shy of 60 data points. As I gather more data I plan to do a bunch of analysis in Excel to try to find some patterns in the data. I want to wait until I have at least 100 data points before I begin doing any Excel analysis though. Since each key cycle counts as a data point they add up quickly.

 

Here are my observations so far: if the car is off for only a short period of time the ending SOC numbers match exactly to the beginning SOC numbers of the subsequent trip. If the car comes home with a warm battery after driving awhile and then sits overnight in the warm garage at our apartment the SOC also hardly changes. However, when the battery temp changes significantly while the car is sitting there is a change in SOC at the beginning of the next trip. Sometimes this has been more than 10% of the useable SOC, although the jump often seems to be around 5%. Sometimes the useable SOC goes up, sometimes it goes down. It seems that when a warm battery cools significantly while sitting the useable SOC drops. When a cold battery warms significantly while turned off (such as when our car sits overnight in the heated garage) the useable SOC increases. However, these observations are based on only 2 data points each...more observation is needed to confirm. However, this behavior follows what is already expected based on the performance of Li-ion batteries in general so it is not surprising.

 

Also, I've learned a lot as regards the useable SOC and the battery icon on the dash. The car will not allow the useable SOC to get below 15% when you're driving. When the useable SOC reaches 15% the EV threshold completely disappears and any pressure on the gas pedal will bring the ICE to life. Also, a useable SOC of 50% equals a battery icon that is about 2/3 full on the dash. Anytime the useable SOC is below 50% and the ICE is on the computer will load up the ICE to send about 15 amps of current into the battery. It seems that the computer likes to vary the load on the ICE as little as possible and instead varies the generator load up and down with the slight vibration in your pressure on the pedal due to road bumps, etc. Once the useable SOC reaches 50% the load on the ICE will drop to under 10 amps flowing to the HVB. When the useable SOC reaches 60% the dash battery icon is almost full. Once the useable SOC reaches 60% the computer will no longer use the ICE to charge the battery. At about 60% useable SOC you can do ICE High mode on the freeway. Before the PCM update the car would maintain the battery around 60% useable SOC when driving faster than 62 MPH. The only way to get the battery above 60% of the useable SOC is when going down a mountain. A C-Max Hybrid owner has reported that this XGauge code will reach 100% when going down a mountain and that when it gets that high then engine braking starts.

 

Also, slowing to a stop from 55 MPH with a 100% brake score raises the useable SOC slightly more than 20%. Slowing to a stop from higher speeds would put proportionately more energy back into the battery. You could potentially go from ICE High mode with a 60% useable SOC up to 100% useable SOC just from regen braking.

 

I have also been able to graph my useable SOC versus total SOC to see how much of the battery the computer lets us use.

Based on the portion of my data that I have typed up, only 28 data points, I was able to get a regression equation with an r² of .9976. This means that this equation is able to use the useable SOC to predict 99.76% of the variation in the overall SOC. This is very high accuracy and shows that these two data points have a linear relationship.

The equation is: y = 0.3849x + 0.3113. y is the overall SOC and x is the useable SOC.

 

This provides us some interesting data:

• The intercept is 31.13%, this means that if the useable SOC showed 0% the actual battery SOC would be 31.13%
• If we plug in 100% for x we get a result of 69.62% (0.3949 x 1 + 0.3113)
• This means the absolute limits for HVB charge are 31.13% and 69.62%
• Since the car doesn't really allow the useable SOC to go much below 15% and doesn't often let it go much above 60% we can see that in normal driving the range is 37.05%-54.82%
• However, most trips don't see the useable SOC get as low as 15%, it's very hard to keep the car in EV mode once the useable SOC gets below 25% unless you're cruising on flat ground at low speeds with a minimal power demand. A typical useable SOC range while driving is 25-60%, this equates to 41.00%-54.82%

This data shows us how carefully Ford manages the charge of the HVB to prolong its life. Even if the HVB should experience a 10% loss in capacity, since we use such a small portion of the battery, we are unlikely to notice.

 

I have also observed how carefully the battery temp is managed. I have seen the battery fans come on when the HVB temp is in the low 70s but climbing while driving. This shows that Ford also carefully monitors the temperature to protect the battery and prolong its life.

 

Here is my SOC graph and equation

Edited October 28, 2013 by hybridbear

[hybridbear]

Future equations will look to establish a relationship between trip length & MPG, outside temp and MPG, beginning coolant temp & MPG and more. I also want to make use of the beginning coolant temp data to try to create an equation that predicts the warm-up MPG penalty versus starting with a warm ICE. A warm ICE will be defined as a starting coolant temp of 40^oC or higher since 40^oC is the threshold for turning off the ICE.

Edited October 28, 2013 by hybridbear

[corncobs]

I wonder if Ford engineers read this and think how much further do these guys wanna reverse engineer our hybrid system.

 

Very cool stuff HB.

[hybridbear]

I typed up another 15 trips worth of data today and then updated my useable SOC to overall SOC graph & trendline. I now have 88 data points. The trend line changed slightly, but not to a meaningful degree. The r² is now .998 indicating that the data is now even more accurate.

 

I also have more data now regarding SOC changes while the car is turned off.

 

Friday we drove over 50 miles throughout the day and arrived home in the evening with the HVB temp in the high 70s and the useable SOC showing 49%, Saturday morning the HVB temp was in the mid 70s as the car had sat overnight underground. The useable SOC had jumped to showing 55% when I started the car.

 

On Saturday at one point the HVB temp was in the upper 60s and I parked the car outside for about 5 hours. When I came back and started it again the HVB temp had dropped into the upper 40s as the outside temp was in the 30s. During this time the useable SOC dropped 7%. While driving the car home the HVB temp reached the lower 70s. I was only home for about a half hour before leaving again. Upon starting the car to leave the useable SOC had jumped 14% versus the number when I turned the car off.

 

On Sunday, while the car sat outside and the HVB cooled compared to when the car was shut off I got back in after about an hour off and parked in the cold to find that the useable SOC had dropped 11% while the car was sitting. Later on in the day the useable SOC jumped 19% when the car was parked with a warm HVB for a few minutes while running an errand. From my last trip on Sunday to starting the car to drive to work today the useable SOC jumped 6% while it sat underground. When I got home on Sunday the car had been outside for a few hours and thus the HVB temp rose from Sunday night to Tuesday morning.

 

It seems that the useable SOC will jump around when the HVB temp changes while the car is off. If the HVB cools below its ideal operating temp of low 70s then the useable SOC drops. If the HVB temp rises from having been cold to its ideal temp of low 70s the SOC seems to rise. You'll also see the useable SOC rise for your next trip if you start a trip with a cold HVB, warm it up through driving and then turn off the car. I see this consistently when I take the car to work and then run errands after. The car starts the day with a warm HVB from being parked underground. My end SOC when I arrive at work is significantly higher than what the car displays when I leave work in the afternoon since the HVB cooled significantly during the day. After I drive and warm up the HVB I then see a jump in SOC the next time I start the car.

[lolder]

A 60% degradation of the HVB did not affect the MPG of a gen 1 Prius in these government tests: http://avt.inel.gov/pdf/hev/end_of_life_test_1.pdf

The transient demands on a HEV HVB require that it only not fail in an open or short circuit mode.

The system monitors for both events and in the case of an open cicuit the vehicles become inoperative and coast to the road side. I doubt that any HVB variations are causing the low mpg that some posters are reporting. As winter approaches, be prepared for a new spate of low mileage reports.

[hybridbear]

Future tests I'd like to run would include bringing the car to a complete stop from various starting speeds (i.e. 55 MPH, 45 MPH, 35 MPH, etc) to see how much the SOC climbs in each case. Based on what we now know we can thus reverse engineer the amount of electricity that went back into the battery from that stop. Since we know the beginning speed we can calculate how much kinetic energy the moving vehicle possessed at that speed. Factoring in approximations for tire rolling resistance we can approximate how efficient the regen braking is.

 

I'd also like to run some tests where I accelerate from 0 MPH to a set speed and then brake back down to 0 MPH. I would monitor the beginning and ending SOC which would allow us to see how much electricity is lost due to the inefficiencies of the electric motors and from transmission losses in the high voltage wires. However, winter is here and I'm not going to do these tests in the cold. They'll likely have to wait until next spring.

Edited October 29, 2013 by hybridbear

[hybridbear]

I'd really like to gather more data. The spreadsheet I'm using for tracking only takes a few seconds at the beginning and end of each trip to document. Is there anyone else who has a ScanGauge and is interested in this? I could send you my spreadsheet template and then I could gather more data. The challenge for me is that almost all of our trips are less than 7 miles, with many being less than 3 miles. On such short trips the swings in MPG are huge! It would be nice to get data from a user who drives a longer commute to gather data for longer trips. If there's anyone interested, please let me know!

[hybridbear]

Watching the LOD and HP outputs more closely it seems that the FFH ICE is most efficient when the overall power demand is at least 31 HP. Between 31 and 46 HP the LOD shows >85. If you go above 46 HP then your acceleration coach bar will drop below 100%. It's only possible to achieve this level of load with the generator placing a load on the engine to charge the HVB. You would have to really accelerate hard to get this kind of power demand just for acceleration. Accelerating between 1.5 & 2 bars on the Empower screen seems to be the optimal acceleration point for this.

 

This leads me to believe that in the range of 31-46 HP the ICE is operating in its most efficient BSFC range.

[hybridbear]

Here are some recent battery observations in the cold...

I've seen the car limit power in EV to only 1 bar on the Empower screen even when SOC is high in the cold. It appears that this happens when the heat is on and the coolant is almost too cold to continue making heat. Thus the car limits your EV by kicking the ICE on at lower power demands. I've also seen the 1 bar limit to EV when the HVB is very cold. With our cold weather I've seen the HVB temp be below 0. When the HVB is cold there is a noticeable difference in how it operates. When it's that cold it discharges much more quickly and charges more slowly. Since it discharges more quickly when very cold you cannot get as many amps out of it which limits how many watts the electric motor can provide to the wheels. In the cold weather after the car sits outside the HVB might only warm up about 30 degrees above ambient after an hour of driving. Once the cabin temp heats up the car will turn on the HVB fans to warm up the battery. Once the battery warms up then you can get more than just 1 bar of EV.

 

Since we park underground the car & HVB start out at about 60F in the morning. On some of my longer drives to Owatonna I have seen that the HVB reaches about 75F. In the summer I don't recall ever seeing the HVB fans come on with an HVB temp of 75F. With outside temps less than 10F it seems that the HVB fans come on early in my drive and run constantly. I usually have the HVAC set to 68 or 69. When I do a long drive after the car has been sitting all day and the HVB temp is cold, I've noticed that once the cabin warms up the HVB fans come on. I assume that at this point the HVB fans are on to warm up the HVB since the cabin is warmer than the HVB temp.

[acdii]

Thats pretty much what I thought. With the BD, I noticed that after they had road tested it several times in a matter of a few hours, it was able to get over 2 bars of EV, which it never did before(someone noticed it in the video I took as well). I did notice a big difference in the cold temps with EV and ICE performance in my current car, which is what contributes to the lower MPG that I am seeing.

 

We dont need an ICe block heater, we need a battery pack heater!

[hybridbear]

Thats pretty much what I thought. With the BD, I noticed that after they had road tested it several times in a matter of a few hours, it was able to get over 2 bars of EV, which it never did before(someone noticed it in the video I took as well). I did notice a big difference in the cold temps with EV and ICE performance in my current car, which is what contributes to the lower MPG that I am seeing.

 

We dont need an ICe block heater, we need a battery pack heater!

If you turn off the Inst MPG gauge the bars change. I always have the instant MPG on. 2 bars with Inst MPG on is not equal to 2 bars with Inst MPG off.