Cmax Energi HVB Battery replaced under Warranty

[plus 3 golfer]

Actually after the Federal Tax Credit on the Energi in Dec. 2012, it wasn't much more than a Hybrid SEL.  I really wanted to buy an Energi but given its slightly smaller hatch space, a premium over the Hybrid, and the known issue with the Nissan Leaf in hot climates in late 2012, I went with the Hybrid.  I knew at that time (based on the Leaf and my research) that I would have to limit my number of times charging especially in the summer in Phoenix area (my garage doesn't get much below 100F when low temps are around 90F.   I also knew that Ford used air cooling of the HVB.  So, my estimates were that to mitigate HVB capacity fade, I would never recover the cost difference between the Hybrid and Energi with EV wall power in a reasonable time period (I used 5 years).

 

But if there is a silver lining, the Energi can still be used just like a Hybrid as it is a great car.  But it is frustrating that Ford couldn't have done something even after a few years to help mitigate capacity fade.  I believe it would have been relatively easy for Ford to modify software and add a toggle in the left hand display to limit charging to say 80 to 90% of the 7.6 kWh capacity and inform owners of the consequences of charging fully frequently and during high temperatures.  Yes, one might lose say 5 miles of range by using the toggle, but there's at least 6 months where one could likely fully charge overnight with minimal capacity fade.  Of course wouldn't do that because they would be admitting to a "bad design" and Energi sales would tank because the "reasonable true" range in hot climates would also tank. What I really find amazing is that Ford continued to sell the Energi to uninformed buyers through 2017 and still selling Fusion Energis albeit with a larger 9 kWh HVB. 

 

Larryh on the Fusion Energi forum has this great thread on the HVB in 2016.  Here's an excerpt from it.

 

Now consider someone in Phoenix, AZ.  During the summer, the HVB temperature will be around 45 C and during the winter around 27 C.  At 100% SOC, that corresponds to capacity fades rates of -7.4e-3 and -4.8e-3 (the value for 45 C is off the chart so I have to guess).  Assuming 50% of the time is winter and 50% is summer, the average degradation rate is the average of those two numbers or -6.1e-3/sqrt(day).  At that rate, the battery capacity degradation will reach 20% in 2.9 years.   The actual degradation will be greater than 20% after 2.9 years since I have not included degradation due to cycling.  A test of the Nissan LEAF driven in Phoenix, AZ can be found here:  https://avt.inl.gov/sites/default/files/pdf/vehiclebatteries/FastChargeEffects.pdf.  In this test, the actual battery degradation was 25% after 1.5 years.  Cycling was probably responsible for 8% of the 25% degradation.  

 

 https://www.fordfusionenergiforum.com/topic/4121-hvb-degradation/#comments  

Edited June 7, 2020 by Plus 3 Golfer

[Billyk24]

Running EV in piecemeal fashion as Raj would state, is working well for me.  Only have 17k on my Energi as I don't drive it much during the winter months and try to avoid during blistering hot summer days.     

 

[C-MaxA2]

https://www.freep.com/story/money/cars/mark-phelan/2020/06/08/2020-ford-escape-plug-in-hybrid/3150813001/

 

Says the new Escape plug in is supposed to go 37 miles on battery only.  Interesting!   

[plus 3 golfer]

3 hours ago, C-MaxA2 said:

https://www.freep.com/story/money/cars/mark-phelan/2020/06/08/2020-ford-escape-plug-in-hybrid/3150813001/

 

Says the new Escape plug in is supposed to go 37 miles on battery only.  Interesting!   

The HVB is 14.4 kWh.  My guess is the usable EV kWh are likely at least 10 and maybe as high as 11 kWh.  So, that would put the miles / kWh in the range of  3.3 -  3.7 miles/kWh.  It's likely very doable if one keeps speed down and little to no cabin heating / cooling.  With hypermiling some will likely reach 50 mile EV range.

 

I also note that there is a drive mode that allows charging the HVB while driving.   This "charging" mode could be very useful to keep ICE in its "sweet spot" at low to moderate speeds (when wall power will not be available for many miles) to replenish the HVB EV kWh.  Seems like this would work well and efficiently in city and suburban driving for trips significantly longer than 37 miles.   Maybe Ford plans to implement an "autonomous charging mode" algorithm based on ones planed trip route, traffic and climate conditions!  Might as well go all the way with autonomous driving.?

 

Paul, when you get your Escape PHEV, you are going to have to play around with this charging mode.

 

 

[fbov]

5 hours ago, Plus 3 Golfer said:

... Paul, when you get your Escape PHEV, you are going to have to play around with this charging mode.

And Paul, you'll love stop-n-go cruise control... it's an automated drafting system. 

Frank

[Billyk24]

7 hours ago, Plus 3 Golfer said:

The HVB is 14.4 kWh.  My guess is the usable EV kWh are likely at least 10 and maybe as high as 11 kWh.  So, that would put the miles / kWh in the range of  3.3 -  3.7 miles/kWh.  It's likely very doable if one keeps speed down and little to no cabin heating / cooling.  With hypermiling some will likely reach 50 mile EV range.

 

I also note that there is a drive mode that allows charging the HVB while driving.   This "charging" mode could be very useful to keep ICE in its "sweet spot" at low to moderate speeds (when wall power will not be available for many miles) to replenish the HVB EV kWh.  Seems like this would work well and efficiently in city and suburban driving for trips significantly longer than 37 miles.   Maybe Ford plans to implement an "autonomous charging mode" algorithm based on ones planed trip route, traffic and climate conditions!  Might as well go all the way with autonomous driving.?

 

Paul, when you get your Escape PHEV, you are going to have to play around with this charging mode.

 

 

Lifting your foot off the gas pedal and coasting will induce regenerative charging while in the "auto" and "EV later" mode.   You don't have to use the "new" mode. 

[plus 3 golfer]

 

2 hours ago, Billyk24 said:

Lifting your foot off the gas pedal and coasting will induce regenerative charging while in the "auto" and "EV later" mode.   You don't have to use the "new" mode. 

 Regeneration is capturing energy that is otherwise lost.  This charging mode runs ICE to charge the HVB which one can’t do in the Energi.  You would likely  not use the charging mode until the EV range was low, then only charge when efficient to do so and only to get enough EV range to get to wall power.  
 

I assume the charging mode will run ICE at its most efficient points on the BSFC map taking into account road load by varying charging load to achieve this.  This would be essentially no different than normal hybrid operation except the entire battery apparently could be recharged in this manner.   We don’t yet know how the algorithm works but it apparently gives another tool to use to increase fuel economy and lower overall fuel cost.  I can foresee switching modes frequently (likely based on speed and terrain) for most efficient results.  I believe with practice and FE feedback one can increase FE using the charging mode (hypermilers should like this feature).
 

I would love to run tests and analyze the data to evaluate the charging mode effectiveness.  But I don’t need to replace my C-Max yet and then I don’t know whether I’d replace it with the Escape PHEV.

[ptjones]

12 hours ago, Plus 3 Golfer said:

 

 Regeneration is capturing energy that is otherwise lost.  This charging mode runs ICE to charge the HVB which one can’t do in the Energi.  You would likely  not use the charging mode until the EV range was low, then only charge when efficient to do so and only to get enough EV range to get to wall power.  
 

I assume the charging mode will run ICE at its most efficient points on the BSFC map taking into account road load by varying charging load to achieve this.  This would be essentially no different than normal hybrid operation except the entire battery apparently could be recharged in this manner.   We don’t yet know how the algorithm works but it apparently gives another tool to use to increase fuel economy and lower overall fuel cost.  I can foresee switching modes frequently (likely based on speed and terrain) for most efficient results.  I believe with practice and FE feedback one can increase FE using the charging mode (hypermilers should like this feature).
 

I would love to run tests and analyze the data to evaluate the charging mode effectiveness.  But I don’t need to replace my C-Max yet and then I don’t know whether I’d replace it with the Escape PHEV.

Only time I would use that feature would be going down hill or I needed to heat up the cabin. Using the ICE isn't very efficient.

 

Paul

[plus 3 golfer]

6 minutes ago, ptjones said:

Only time I would use that feature would be going down hill or I needed to heat up the cabin. Using the ICE isn't very efficient.

 

Paul

The assumption is that one has to operate in hybrid mode (EV only battery capacity is depleted) and that one would not use charging mode simply to fill the plug-in HVB,   In hybrid operation, all energy comes from the fuel  Thus, one wants to minimize the fuel cost between wall charging.  It’s not about comparing cost of wall power vs fuel cost.  ICE has to be used to burn the fuel to operate the vehicle in hybrid mode.  There’s no other way even though converting the energy in the fuel with ICE is only maybe 35-40 % efficient.  
 

There are many times when my hybrid battery is virtually  charged full by ICE (like when on level roads or going down a longer slight downgrade) and one runs in negative split mode. Negative split mode is not a preferred mode as one is not reaping the benefit of hybrid operation.  ICE rpm drops by spinning generator  to supply rpm to keep car at same speed but with very little load on ICE, ICE is still likely out of its most efficient operating range.   Yes, one can back off pedal and drive in EV mode depleting charge and start the process again.  But, is that the best use of EV?  If one had more battery storage, ICE could pick up some charging load instead of operating in negative split mode and perhaps operate more efficiently.  The added EV would then be used where one would get the most benefit where ICE otherwise might have had to be used very inefficiently.
 

There have been several research papers written on optimization of a plug-in by operating ICE to charge the HVB, propel car, and provide traction motor power to assist propelling car without using HVB - perhaps using ICE for all at the same time.  The issue is that current algorithms currently have no look ahead, predictive function.  So, assumptions have to be made in attempting such optimization.  By adding a charging mode available to the driver, the driver can attempt to use his predictive skills in the optimization process.  

[ptjones]

From what I have read the ICE at best is 25- 30% efficient with 30% heat losses into the cooling systems and 30% out the exhaust pipe. The remaining losses in the mechanical systems.

 

Paul

[Billyk24]

 This charging mode runs ICE to charge the HVB which one can’t do in the Energi. ----- are you claiming it is impossible to recharge (state of charge) the HVB by coasting/letting your foot off the gas pedal?      

[plus 3 golfer]

1 hour ago, ptjones said:

From what I have read the ICE at best is 25- 30% efficient with 30% heat losses into the cooling systems and 30% out the exhaust pipe. The remaining losses in the mechanical systems.

 

Paul

Exactly, as I should have said "at most" 35-40%, as Toyota has smaller none hybrid engines that supposedly approach those numbers.  Also, the Prius 1.8 liter engine has very high thermal efficiency.

 

"Another industry benchmark is Toyota’s retuned high-volume 1.8L 4-cyl. Most engines have a thermal efficiency of about 35%, with the best a few points higher. By continuously combustion, heat management and reducing friction, the Atkinson-based 2ZR-FXE in the Prius is the first gasoline engine in the world to achieve maximum thermal efficiency of 40%, Toyota says."

 

In addition, the reason hybrid operations improve overall FE improves is that ICE is not operated in areas of the BSFC map were efficiency is poor.  This is why hybrids get more mpg out of a gallon of fuel than the same car with a conventional ICE. There is no magic just physics - goal is to always operate ICE at its maximum thermal efficiency. We don't know what the thermal efficiency of the Escape ICE is but we do know that if we can operate the vehicle in Hybrid mode more efficiently, FE will improve.

 

 

 

https://newatlas.com/toyota-atkinson-engines-improved-thermal-fuel-efficiency/31615/#:~:text=The larger 1.3-liter Atkinson,thermal efficiency of 38 percent.

[plus 3 golfer]

12 minutes ago, Billyk24 said:

 This charging mode runs ICE to charge the HVB which one can’t do in the Energi. ----- are you claiming it is impossible to recharge (state of charge) the HVB by coasting/letting your foot off the gas pedal?      

When you are coasting (take your foot off of pedal) ICE does not run except for the conditions I described previously in another thread.  Max AC, heat, warm up engine, and so forth.  So, once car reaches normal conditions are you saying that ICE runs in the Energi when you take your foot of pedal?  We are not talking about regeneration by the traction motor when coasting which is normal.  I have never read anywhere that the Energi can be charged by selection of a mode which will keep ICE running and charge the HVB.   If it's possible  please post how its done.

 

[plus 3 golfer]

Here's an example of how hybrid operations improves FE.  Attached are 2 charts for the Prius 1.8 liter engine.  The second is a BSFC curve which shows torque and rpm on and superimposed are Brake Specific Fuel Consumption Curves.  The units are grams/kWh of fuel consumed at specific rpm and torque.  The goal of hybrid operation is to improve the operating characteristics such that BSFC moves from a high number to a lower number for the same rpm.  What you will notice is that at a fixed rpm, ICE can operate at different efficiency based on the amount of torque which it supplies.  So, what the hybrid algorithm does is to increase ICE torque from the base torque needed to propel the car.  The increased ICE torque is used to generate electric power which can be stored in the HVB.  In addition, the fuel used by doing this decreases in g/kWh for propelling the car. So, torque required to propel the car hasn't changed but fuel to propel the car is less.  Now, fuel is needed to supply torque to the generator but it is at a very efficient BSFC point.  There are losses in converting the mechanical power to electrical power for storage and reuse.  But, the overall gain in efficiency via hybrid operation is positive resulting in increased FE.  Of course the greatest benefit is when EV is used on initial acceleration from a stop so that ICE can be shut down.  ICE is very inefficient for use on initial acceleration from a stop.  In essence, energy stored in the HVB when ICE ran very efficiently replaces the energy that would have been required using ICE to accelerate from a stop.  This nets a fuel savings.  The same happens on highway cruising especially if ICE torque is very low and EV can be used instead.  

 

The first "colored dots" graph shows actual operating data.   Assume engine rpm is 2000 rpm and torque is 60 (likely going down a grade) as this is not an efficient operating point.  The algorithm can spin the generator to maintain the 2000 rpm need to keep speed constant (negative split mode).  Lets's is the generator can add 400 effective rpm to the output shaft and ICE rpm can be reduced by 400 to 1600 rpm.  The ICE is still supplying 60 Nm of torque.  So, now ICE efficiency has improved somewhat but still not very efficient.  But since we have a HVB with room to store additional energy, rather than operate in negative split mode the algorithm operates in positive split mode by increasing load on ICE by generating electricity with the generator.  Engine rpm will have to increase from 2000 rpm somewhat say to 2400 rpm and  assume the generator is consuming 30 Nm of load.  ICE is now operating in the "cyan dot" at 2400 rpm and 90 Nm or the most efficient region of the BSFC.

Edited June 14, 2020 by Plus 3 Golfer

[stolenmoment]

So, to summarize: the software should either keep the engine turning in its most efficient regime, or shut it off, and we know how to do this.  If efficiency generates more torque than needed to turn the wheels, store the excess juice in the battery.

[plus 3 golfer]

3 hours ago, stolenmoment said:

So, to summarize: the software should either keep the engine turning in its most efficient regime, or shut it off, and we know how to do this.  If efficiency generates more torque than needed to turn the wheels, store the excess juice in the battery.

We hope the “charging mode” will do this and not disregards efficiency simply to fill the HVB.
 

I can envision if it’s done properly, that the red and yellow dots in the graph which are  below the cyan dots will “move up” towards the cyan dots and the mostly red and maybe some yellow dots above the cyan dots will “move down“ by using EV to supply some of the torque to bring ICE into the blue dot area. If too much charge is accumulating in HVB (you would want charge depleted before plugging in), one could turn it off and run in EV. 
 

Otherwise, it’s just a “gimmick” - a trick or device intended to attract attention, publicity, or business.  Ford has never done this - have they?  ? I will note that in normal daily driving, most likely would have no need / use of the charging mode as the average daily commute is around 16 miles one way.  

 

I believe if it works like above, it could improve FE several % on the one or  two round trips we make every week of 100 + miles and on the several longer trips we take each year.  I hope once the Escape plugin is available for testing and review, the reviewers will give feed back on using the charging mode.

[pureenergi]

On 6/6/2020 at 3:58 PM, C-MaxA2 said:

The Energi was a flawed concept to me from the beginning.  I looked at both models of the C-Max and read comments like yours I had to ask myself if after 20 miles was worth having a 267 lb. 'passenger' sitting in the back until there was a recharge. Ford charged quite a bit more for it as well.  Now I see Energi models selling for lower than a straight Hybrid C-Max. 

 

The thing about that 276lb "passenger" is that not only can that passenger get you 20 miles of range (when new) that passenger sucks up more regen than the standard hybrid battery so you can do 1-pedal driving far more often.  You get a higher % of your energy back than with the regular battery.  And that battery eliminated a lot of cold starts and around-town ICE driving which is harder on the engine.  You can have a car like mine that has 80,000 miles but only 30,000 miles so in theory our powertrains should last much longer, but in reality it may just be the engine - both of our transmissions seem to suffer from the transfer shaft issue.  And that battery qualified the car for a significant federal and CA state (in my case) EV rebate and got me about 5(?) years of HOV lane usage as a solo driver in CA, so there's that too.  100% would do again!

[ptjones]

I don't think you have to worry about the ICE, I have almost 258k miles on my CMAX and has no problems from BlackStone Labs  testing.

 

Paul

[pureenergi]

Adding a DP to this thread and hoping for the same experience as the OP.  Just tested my battery that's showing serious signs of degradation after 80.1k miles, 52k of which were EV miles.  Temperate climate - SF Bay Area in CA.  I use a combination of Level 1 and Level 2 charging - the car is rated for both, and Ford sets it to charge at a conservative (3.3 kWh?) speed on Level 2 so I figure both are fine for the battery, (if Ford designers felt otherwise they would have limited the charge rate even further) but after my range started to really suffer and I understood more about Ford's inadequate air cooling and heating for the battery I've started to use Level 1 as much as possible to treat the battery as gingerly as possible.  Range indicator at start is usually around 14 miles in 50-70 degree temps.  From a full charge to a depleted battery I have gotten 3.3 to 3.6 kWh out of the battery on my last 2 tests in the Ford Mobile app.  Just did one today - results below, about 60 degree temps at time of drive.  I took it uphill so I wouldn't use much regen and really test just the battery capacity, not capacity+regen, so only got 6.2 miles of range before the ICE kicked in and I immediately stopped the test and turned the car off.  I'm starting to monitor how long it takes to charge as well and may use a Killawatt to measure total amount it can take in, but there's usually around a 10%(?) loss from energy used by the charger to energy stored in the battery on average so I'll factor that in.

 

I'll try to test it every month to build a case for replacement.  My reasons are:

 

1.  Air cooled and not liquid cooled has a negative effect on battery life.  Not sure how the battery is heated during cold weather while plugged in overnight but that could have an effect too - car is parked outside but temps almost never get below freezing, only a handful of times on road trips.

2.  Over 50% battery degradation after 80k miles is a huge amount - I have 47% of my original 7.6kWh battery capacity if the 3.6kWh until empty is correct, and only 43% if my other test is correct - so anywhere from 43-47% of capacity remaining after 80k miles.

3.  The car is a brick if the HVB dies - I have to spend $9k to get my car to move if the battery dies, whereas a C-Max hybrid or plain ICE would be able to keep going with a cheaper or free repair.  If I have to pay $9k for a new battery, my car is essentially totaled since the battery will cost more than the blue book value.

Edited September 22, 2020 by pureenergi

[Billyk24]

Ford's warranty does not state anything about degradation.    Because of this fact, you will not obtain a replacement unless there is something else outside the battery cells that caused the loss of capacity.   Your HVB will not die.    There is a Facebook site owner driving the Energi without charging it as she has an issue.

[pureenergi]

2 hours ago, Billyk24 said:

Ford's warranty does not state anything about degradation.    Because of this fact, you will not obtain a replacement unless there is something else outside the battery cells that caused the loss of capacity.   Your HVB will not die.    There is a Facebook site owner driving the Energi without charging it as she has an issue.

That's good info about the person still driving it if she has an otherwise inoperable HVB battery for whatever reason.  I'm just going from posts like this: "My service advisor said 3.8 kwh is the lower capacity warranty limit before they replace the battery pack." and this: "Dealer is telling me my reduced capacity is due to a faulty charger." and this: "Battery Warranty for Low Capacity (4.1 kWh)" - I hear what you're saying, but I think there's enough evidence in these posts that it's worth it for people suffering extreme degradation (I'd say over 50% is "extreme") to document their issues and work with their dealer to see what the cause is and see if they do indeed get warrantied or fixed without replacing the battery.

[cortb]

On 6/11/2020 at 1:13 PM, plus 3 golfer said:

We hope the “charging mode” will do this and not disregards efficiency simply to fill the HVB.
. . . 

Otherwise, it’s just a “gimmick” . . . 

 

I'm starting to wonder if it should really be called "Generator Mode". Like if your power is out, why not use that nearly 40% efficiency engine to fill up 14kwh worth of battery, so you can charge up laptops/phones or maybe run the fan on your gas furnace for a few hours or something? 

[SnowStorm]

14 hours ago, cortb said:

Like if your power is out, why not use that nearly 40% efficiency engine to fill up 14kwh worth of battery,

Totally agree!  Its a shame hybrid car manufacturers aren't doing this already.  Everything is there: battery, high efficiency low pollution ICE, inverter and controls to start/stop the ICE as needed.  You could have 10kW 240/120 volts no sweat.  And its with you wherever you go!

[Billyk24]

On 9/22/2020 at 7:13 PM, pureenergi said:

That's good info about the person still driving it if she has an otherwise inoperable HVB battery for whatever reason.  I'm just going from posts like this: "My service advisor said 3.8 kwh is the lower capacity warranty limit before they replace the battery pack." and this: "Dealer is telling me my reduced capacity is due to a faulty charger." and this: "Battery Warranty for Low Capacity (4.1 kWh)" - I hear what you're saying, but I think there's enough evidence in these posts that it's worth it for people suffering extreme degradation (I'd say over 50% is "extreme") to document their issues and work with their dealer to see what the cause is and see if they do indeed get warrantied or fixed without replacing the battery.

The battery can fall under warranty replacement if a component outside the battery cells malfunctions and it is determined this caused/contributed to battery degradation.   The 3.8kWh limit is meaningless unless one can show what the previous sentence stated.  In your case, the dealership is claiming a faulty charger is responsible.  Without the faulty charger, you will be told to pound sand. 

[jzchen]

On 6/7/2021 at 8:24 AM, SnowStorm said:

Totally agree!  Its a shame hybrid car manufacturers aren't doing this already.  Everything is there: battery, high efficiency low pollution ICE, inverter and controls to start/stop the ICE as needed.  You could have 10kW 240/120 volts no sweat.  And its with you wherever you go!

Our '18 Clarity PHEV has a charging mode you press and hold a hybrid mode button for a while and it starts the ICE to charge the battery.  Recommended use is on a long flat highway/freeway where constant speed is driven.