Ability to limit the charging; ability to start/stop via app

[michael]

I would like to be able to stop charging at 80, 85 or some desired percentage of charge, just like the Leaf and Tesla provide.

As it stands, I have to monitor via the mobile app and go out to unplug.

Please provide:

1. A way to specify the maximum desired charge percent; and

2. A way to stop/start charging via the mobile app

Please?

 

[WattsUp]

Why do you want this?

 

[EVA]

I'll ask a similar question, why would this be necessary? It seems to me there is a lot of evidence that Ford has a large safety cushion around 100% and 0% charge. I think WattsUp is one of the people that have figured that out. I also bumped into it driving a Ford Fusion Energi. Ford appears to have taken a very conservative approach to the batteries.

I'm assuming you think this is necessary to somehow treat your batteries nicer, and maybe extend their life?

Let me guess why Nissan does it. They don't have thermal management on their batteries, and they have a tweak where you can actually see 100% of the battery. Yep, wouldn't want to charge to 100% very often, got it.

I'd guess Tesla has it so you can get the car to their free supercharging stations, or another place that is free as opposed to feuling up 100% at home where you pay for the electricity. I'm thinking they built in a convenience factor. After all, those are massive batteries in that car.

 

[EVA]

You can actually do most of what you've asked for (well not from the app, but you can run the website from your phone). Go to My Ford Mobile, click on My Account. Then in the band just below the main one, select Notifications. You can set a one time notification for when the battery gets to a certain percentage or particular range. When you get the text message, go to your car and unplug it.

 

[michael]

Good questions.

Everything I have read indicates that the closer you can keep your battery to 50% state of charge the lower the degradation. Especially that the time spent at full charge is harmful. It's a very slow effect of course but we are talking about years of cumulative time. My daily commute needs about 60% so I think there is no downside and some possible advantage about trying to run between 85 and 25 rather than between 100 and 40

And at present I do run out and unplug. I'm asking that the car simply disconnect without need for me to do that. Or be unable to drop things and run outside

Furthermore, on hot days you don't want to unplug the car. The thermal management system operates only when it's plugged in.

In summary, why shouldn't they provide that capability?? The go-time and value charge by location features seem less important and more gimmicky.

Just my opinion. I'd like the feature!!

 

[WattsUp]

Everything I have read indicates that the closer you can keep your battery to 50% state of charge the lower the degradation. Especially that the time spent at full charge is harmful.

By "full charge" you probably mean absolutely charged to full capacity. But, beware that the FFE battery is never actually charged to its absolute full capacity, more like 90-95%. This has been discussed many times in these forums. Also, only extended periods of time spent at a high state of charge could be harmful. Overnight or anything on the order of days is not considered problematic.

IMO, going out of your way to avoid fully charging your FFE is simply wasted effort, especially if the car is your daily driver. Charge whenever the opportunity presents itself and enjoy your car.

I think there is no downside and some possible advantage about trying to run between 85 and 25 rather than between 100 and 40

Generally, the lower the state of charge, the hotter the battery gets while discharging, and the faster it will degrade. If the battery is discharged routinely (as it the case for most EVs) it would therefore be better to keep the battery at the highest SOC possible, so any discharge will occur "higher up" in the capacity curve, and generate the least amount of heat. For example, if you routinely discharge half of your usable battery capacity, it would be better to discharge from 100 to 50%, versus 75 to 25%.

Just my opinion. I'd like the feature!!

IMO, you're overly concerned about "manually" managing a battery system which has already been designed to perform very well on its own. Some of the things you suggest doing, while probably not particularly harmful, really don't have any evidence to suggest they would be beneficial.

Btw, if you've been reading lots of advice about Leaf battery "best practices", most of it does not apply to the FFE.

 

[v_traveller]

Everything I have read indicates that the closer you can keep your battery to 50% state of charge the lower the degradation. Especially that the time spent at full charge is harmful. It's a very slow effect of course but we are talking about years of cumulative time. My daily commute needs about 60% so I think there is no downside and some possible advantage about trying to run between 85 and 25 rather than between 100 and 40
....
Just my opinion. I'd like the feature!!

I'm with you on this Michael. I normally try not to charge to about 75%-85% at home because I use only about 40% of the capacity going to work. Also, I charge with L1 at home because I don't want to dish out the $$$ for an L2 charger, and I want to minimize the charging done overnight that would occur outside of the 12am-6am super-saver rate period. A programmed shutoff at 80% would work great for me.

On the way home I use 50%-60% of the capacity, so I try to charge to 90%-95% at the L2 chargers at work. I try to avoid 100% charge and here's why. Earlier this year I posted the L2 charge profile of my FFE:

http://www.myfocuselectric.com/forum/viewtopic.php?f=8&t=1020

I'll repost the curve here:

Note that for the last 20-25 minutes, the battery is in "saturation charge", where the last ~2kWh are being stuffed into the battery at a much slower rate than the normal "constant current" charge state. I noticed that the thermal management system often kicks in at a much lower temp than I would expect during saturation charge (lower than 80F ambient for me), so there is stress on the battery when trying to charge to 100% of allowed capacity, even if there is a buffer that Ford programmed in for us. Furthermore, from the batteryuniversity.com article in my previous post reference above:

"Li-ion does not need to be fully charged, as is the case with lead acid, nor is it desirable to do so. In fact, it is better not to fully charge, because high voltages stresses the battery. Choosing a lower voltage threshold, or eliminating the saturation charge altogether, prolongs battery life but this reduces the runtime. Since the consumer market promotes maximum runtime, these chargers go for maximum capacity rather than extended service life."

My observation is that whatever buffer Ford programmed in (evidence of that buffer is the last big drop in the above curve), does not fully eliminate the saturation charge state. Doing so would likely shorten the FFE's "official" range to 70 miles or less.

I suspect Ford struck a balance between range and battery life such that we can enjoy at least 80% (another guess) of the original capacity at least through the 8 year/100K mile battery warranty. But that's just my non-expert opinion. Draw your own conclusions, please.

 

[WindPowered]

I'll ask a similar question, why would this be necessary?

I absolutely think this feature is necessary, and it's not for trying to manage the battery health. Ford's engineers have already taken care of that.

I live up a large hill, over 1000 feet above the valley where most people live and work. The first 6 miles of my morning commute are entirely downhill. As a point of reference I can travel those first 6 miles using 12 wH/m. That's not a typo. 12 wH/m.

So in that downhill leg of my commute, I need to be able to capture all the energy I can via regenerative braking. If the battery is charged to 100%, guess what? I just fly down the hill with no resistance, and all the energy gets wasted, as it gets sent into my brakepads. Because there's nowhere to put it. The battery is full.

Now when I come back up the hill, I use > 800 wH/m for those 6 miles. A massive use of energy to get back home. If I can't average the uphill "cost" against the downhill "savings" (via regenerative braking), I'm throwing money out the window by charging to full. i.e. I'm paying for energy that I'm sending into my brake pads.

If I could have the charging automatically stop at 95%, I'd have room to store the downhill leg of my commute, plenty to handle my daily driving, and there'd be no waste.

That's what I want.


WP

 

[michael]

While we have different reasons for wanting the feature, it seems to me no reason for it not to be included. The car is one big computer. Shouldn't have to walk outside and unplug it to stop charging.

 

[Arthur]

Please provide:

1. A way to specify the maximum desired charge percent; and

2. A way to stop/start charging via the mobile app

I agree, on both points!

I live on a hill that is about a 600-ft elevation, above the surrounding terrain. If I leave home with a 100%-charged battery, I know that I'm going to lose out on a significant amount of regen. In fact, Ford even rubs it in, by programming the car's software to count this loss of regen against me. By the time I get to the bottom of the hill, my "Braking" graphic is way into the red, despite all of my efforts to brake gently and slow down gradually!

As for the optimum state of charge, to maximize battery life, I understand that this is mainly an issue when the battery is allowed to sit, at a HIGH temperature, for long periods of time. So, in cold weather, it's not an issue. In hot weather, what I have heard/read is that the optimum state of charge is between 1/3 and 1/2 of a full charge.

However, if you leave an FFE plugged into a 240-volt charger, it doesn't matter, because the software maintains the battery temperature. With a 120-volt charger, I'm not sure if the same amount of conditioning occurs, especially in very hot weather.

One additional complication: If, during very hot OR very cold weather, I leave my car unplugged, to avoid 100% charge, and the loss of regen that it causes, on the way down my hill, ...I still lose out. When the battery is too hot or too cold, the software limits the current coming into the battery, from regen. So, what I really need is the ability to leave my car plugged in to my charger, without charging the battery. Does that make sense?

 

[michael]

I've been doing a lot of reading recently, and I am absolutely convinced the battery should be charged no more than necessary to leave a reasonable (20-30%) soc before charging

It's true that Ford limits the charge to something less than 100%, but we don't know the exact value. Perhaps 90%?? But the research data are in uniform agreement...lower Soc gives less degradation. And I'm not talking about battery university.com, although they too agree. I'm talking about papers from NREL, JPL, DOD, etc

Also consider that GM limits the Volt to the range 87-22%, that Nissan provides an 80% option, and that Tesla provides a slider control so that users can tailor the charging range to their usage.

And the technical papers uniformly agree that 80% is not some magical number. 70 is better than 80. 60 better than 70. Lower is better. The DOD found that running the batteries between 50 and 0 is far better than between 100 and 50, and actually better than between 75 and 25. That's not my opinion...those are their data.

The argument that short term storage at high soc is not an issue ignores the fact that the damage is cumulative. Being fully charged 24 hours a day for 7 days or 7 hours a day for 24 day, it's the same...168 hours at high soc


So if you are driving 40 miles between charges and have a 3 year lease, you can fully charge all the time and ignore my comments completely. But if you are planning to drive a lot and particularly if you own the car, I'd would limit charging to the level necessary with reasonable reserve. And Ford, like Nissan and Tesla, should provide an easy way to do so


I set my car to begin charging at 5 AM, and I awl outside to unplug it when the charge gets into the low 80s. I shouldn't have to do this. The car is a computer.

 

[julzian]

Please update the software to be able to set a desired charge percentage.

I also live 1000 feet elevation above my town and I have zero regen all the way down to my town. I estimate that I could set mine to charge until 98%
(of the 80% max allowed), the empty 2% would fill by the time I get to town. I estimate that to be somewhere around 1/2 KWh. We would also go through our brake pads about 1/4 as fast for more savings on time and resources. These are heavier than gas cars and will wear out brake pads faster than normal with the regen turned off. Imagine this for an FFE driver 2000 feet or more above their town. The Leaf and the Model S have brought this feature to their software for a few good reasons as you can see from this thread.

I would like to add that I also just purchased the 2014 Fusion Energi and it has the same disability. But it is even worse because if you use L mode to help you brake on a full charge it kicks on the engine to assist braking and it seems to stay in first gear, even above 25mph and the engine revs super loud. I can't even use L mode down the hill unless I sit at my driveway and blast heat for 5 minutes to drain some battery. So you burn fuel all the way down instead of creating power. I am frustrated at this design flaw in such a high tech and expensive machine. But I can't afford a Tesla and don't love the Leaf. I do love the FFE and the Energi except for this single flaw. I did contact Ford about it a year ago for my FFE and made a formal suggestion for an update. I've been waiting patiently.

On a good note, when you go down a long, steep windy hill without a full battery, the FFE and the Energi both handle like energy capturing champions with smooth regenerative braking and an L mode that keeps you from having to touch the brakes except on the steepest of grades.

We need this update ASAP! Thank you in advance Ford.

 

[speediburns]

Old topic, new owner, same need. I also live on a big hill (around 1500'). I havent been watching Wh/m, but I see surplus ratings of 30-60 by the bottom of the hill if I am not fully charged. I hate to be giving that up everyday. Same hill everyday so once I determine just how much regen I get on the hill I can stop charging there every day.

 

[WattsUp]

I havent been watching Wh/m, but I see surplus ratings of 30-60 by the bottom of the hill if I am not fully charged. I hate to be giving that up everyday.

Remember, status numbers like +30 don't mean you've "regenerated" 30 miles.

That's just the guess-o-meter re-estimating how many miles you could drive (relative to its initial estimate) with your average energy usage by the time you get to the bottom of the hill (which would be very little). But, it will quickly re-adjust once you start cruising on level ground, and your average energy usage increases back to normal. The estimate of +30 was just a temporary anomaly.

Sure, you would have regenerated some energy going down your hill. But, unless you're going downhill for miles and miles, and at highway speeds, you are likely "giving up" a relatively negligible amount of energy from regeneration.

I do, admit, though, it would be nice to use regen for braking if only to save your brake pads.

 

[breeves002]

I know this an old topic but I couldn't help reading it.

I would never use this feature, but I see how it could be helpful for some.

I always charge my battery to full overnight and while at work. I don't have time to worry about keeping it at a lower SOC. There is so much conflicting data on what is best for the battery... I find the BEST thing is to keep it COOL. L1 charging does run the cooling fan. L2 is better though.

One thing I will say. My FFE charges to just over 20kW. That leaves me with just over 18kW usable. It charges to 87% SOC. That is a 13% or 3kW buffer zone. I think that is fairly adequate. 351v seems to be full with 4.08v per cell. It will not let you use the last 2kW or so due to the voltage drop being too much during acceleration and to help the battery have a longer life. Li-on batteries do not like to be discharged completely.

On the first page someone said it showed that it was doing a "saturation charge". This is not necessarily true. Once it gets past about 82% SOC the charging rate will slow from 28a down to 10a and even less until it hits its 100% which is 87% SOC on my Focus. This is partially a saturation charge but this is more of an equalization charge. Higher the SOC gets the more resistance the hotter the cells get. Slowing down after 82% does help the heat. However the main reason to slow down is to make sure the cells equalize charge. When charging fast some cells may accept a charge faster then others. After slowing down they have a chance to equalize. This is far different then slowing down for saturation. I believe the battery is going to stay cool enough at 87% SOC that you could just cut off charging. However you'd likely see a voltage drop and SOC drop as the cells equalize after cutting it off from high amperage charging.

 

[michael]

I always charge my battery to full overnight and while at work. I don't have time to worry about keeping it at a lower SOC. There is so much conflicting data on what is best for the battery... I find the BEST thing is to keep it COOL. L1 charging does run the cooling fan. L2 is better though.

There really is no conflicting data...high levels of charge lead to battery fade. And yes, absolutely, temperature is important too.

I agree with WattsUps statement that except for exceptional circumstances the amount of charge to be saved by leaving some margin for an initial downhill run is not terribly significant. What is important is to be easy on the battery. A year ago, it might have been possible to believe that Ford had some design that avoids battery fade. Now that we are seeing cars with high mileage demonstrating fade, that's no longer realistic.

It shouldn't be necessary to take the time to worry about keeping the battery at a lower SOC. There should have been a simple setting to do this automatically like several other manufacturers provide, most notably Tesla.

 

[speediburns]

Remember, status numbers like +30 don't mean you've "regenerated" 30 miles. That's just the guess-o-meter ....

But, unless you're going downhill for miles and miles, and at highway speeds, you are likely "giving up" a relatively negligible amount of energy from regeneration.

I realize the surplus value is a useless feature as driving conditions often change dramatically and yes I realize it is not how many miles have been regenerated.

I go downhill for 6 miles at about 30 miles per hour and have to touch the gas maybe twice for 50 yards or so. Effectively riding the brakes the entire 12 minutes. I know I am not going to charge the car doing this, but I also realize there is no need to have a full charge for my 16 mile commute when 6 miles are downhill. When the car is fully charged there is a lurching that occurs each time I hit the pedal. I assume it is the switching from regen to hydraulic braking, but it is kind of annoying. I dont notice the same effect at lower charge level if I hit the brakes hard enough to engage the hydraulics.

Although this is the first EV I purchased (yes purchased), I have experience with the Rav4, Tesla S, and some friends with the I3 and Leaf. I have to say that the ford mobile interface is pretty crappy. It seems like improving customer experience would not take that much more effort, the hardware is already in place.

 

[jmueller065]

When the car is fully charged there is a lurching that occurs each time I hit the pedal. I assume it is the switching from regen to hydraulic braking, but it is kind of annoying. I dont notice the same effect at lower charge level if I hit the brakes hard enough to engage the hydraulics.

When the car is fully charged it doesn't use regen at all; thus the "jerkiness" you're noticing is the actual brakes. I can sometimes go a good 2 miles before the car starts to regen, other times I don't make it more than 500 ft before regen starts on a full charge.

You can tell when the car is regenerating by the little circle display on top of the battery when you hit the brakes. If the circle is spinning away on top of the battery the car is regening.

 

[hybridbear]

When the car is fully charged there is a lurching that occurs each time I hit the pedal. I assume it is the switching from regen to hydraulic braking, but it is kind of annoying. I dont notice the same effect at lower charge level if I hit the brakes hard enough to engage the hydraulics.

When the car is fully charged it doesn't use regen at all; thus the "jerkiness" you're noticing is the actual brakes. I can sometimes go a good 2 miles before the car starts to regen, other times I don't make it more than 500 ft before regen starts on a full charge.

You can tell when the car is regenerating by the little circle display on top of the battery when you hit the brakes. If the circle is spinning away on top of the battery the car is regening.

The jerkiness is because the car is unsure of whether to allow regen or not. The car will allow regen when below 90% abs SOC. We used to see full charges always being greater than 90% SOC, now a full charge only gets us to 88.5-89.2% SOC so we always have regen right from the beginning. When the car is right near 90% SOC it will try to do regen when you're braking, but then it will decide that it can't charge the HVB anymore so it takes regen away (jerk) then the HVB will discharge from electronics/HVAC/etc loads & thus the car will turn regen on again (jerk) and this process repeats over & over. It does get quite annoying.

You could skip a day or two of charging if you don't need the full range and then you could measure how much energy can be gained from the hill.

 

[speediburns]

If not fully charged, I gain 5% SOC when I leave my house. That is roughly 10% of my typical daily SOC usage.