2012 Drivers battery experience

[Vach]

I am very interested in getting a ford focus electric, but I have a question I wanted to ask anyone who has had the car since it was released.

Have you experienced any loss in battery capacity? I'm not to worried, but I am interested in seeing what actual drivers have to say instead of dealerships an online reviews. minimal battery loss is expected but I am hoping it is nothing like the leaf.

Thanks for your time! =)

 

[Vach]

Really? Nobody? Hmmm...

how about just general loss in capacity over your ownership of the car?

 

[jmueller065]

It is very possible that no one has had the car long enough to notice any loss of charge (From what I can see the longest ownership here is about a year or 12,000+ miles). Given that in a year the battery range loss may not be that large; a 5-10 mile overall range loss wouldn't be that noticeable. Hence no one has replied.

It is also quite possible that the FFE's thermal battery management has minimized any range loss for anyone to be even less making it even less noticeable....

 

[WindPowered]

It is very possible that no one has had the car long enough to notice any loss of charge....

This is most likely the case. Think about what the car is primarily designed for, i.e. a low mileage daily commuter. People aren't racking up hundreds of miles a day on these things, nor have they been around in quantity for any length of time. There's just over a 1000 of these cars "in the wild" and most of those have been in the last 6 months or so.

Low daily mileage * very few days * very few cars = very little to go on.

There just isn't enough data to be had out there right now to make any conclusions about this. Yet.


WP

 

[Vach]

I'm hoping it's the latter. At least, that's the best case scenario. (IE, very good TMS.)

 

[DavidJohnson]

I was reading an article the other day (by Mikael Cugnet) that described the simulation of mileage on the batteries. In order to simulate 100k miles of use in a short period of time, the manufacturers must quickly discharge and recharge the batteries. This can affect the battery capacity two ways, one is heat generated that is detrimental (anything over 104 deg F is bad for the battery) and the second is the extensive use of rapid recharging can be detrimental. Ford says that after simulating 100k miles, they still had over 90% of capacity left. Cugnet claims that in real life, he believes owners will see 15-20 years of use because most owners will not use the batteries the way the OEM test them. That's likely longer than the life of the vehicle. I believe that the general consensus is that a battery becomes 'non-useful' when its capacity falls below 80%. Just my two cent contribution to the discussion...

 

[Vach]

That was an awesome contribution. Thank you very much! I figured that's what kind of testing they did, I just wanted a real world experience from some people. But, as stated, that's probably not really possible yet.

you have a link to the article?

 

[WindPowered]

you have a link to the article?

I think he's referring to this analysis.


WP

 

[JTCalif]

Thanks for that article by Jay Cole (quoting Cugnet).
My practice of leaving the car only partially charged overnight (between 1/4 and 3/4, usually), then fully charging it in the morning shortly before beginning to use it,
may be a good idea, from what Mr. Cugnet wrote.
It may extend the battery's good performance life somewhat, and costs me just a minute a day.

 

[Vach]

But doesn't the system not charge the battery past 80% anyway?

 

[WattsUp]

Not quite. You may be thinking about the fact that EV systems are programmed to discharge only about 80-90% of the total battery capacity. That is, while the batteries are indeed charged to their full capacity, they are never discharged past 10% charge remaining. This is because a complete discharge (to 0%) could cause damage.

The battery pack in the FFE has a total capacity of 23 kWh, of which the car will only ever make use of about 19.5 kWh (which is about 85% of the total). At the point where the FFE indicates that the battery is "empty", it still actually holds a charge of 3.5 kWh.

 

[Vach]

Oooh... really? That makes more sense. I always thought the battery simply charged to "maximum" at 80%, IE: the computer tells the car that it is fully charged at 80% capacity. Therefore keeping it between 20% and 80% at all times.

Thanks for the info.

 

[dmen]

Not quite. You may be thinking about the fact that EV systems are programmed to discharge only about 80-90% of the total battery capacity. That is, while the batteries are indeed charged to their full capacity, they are never discharged past 10% charge remaining. This is because a complete discharge (to 0%) could cause damage.

The battery pack in the FFE has a total capacity of 23 kWh, of which the car will only ever make use of about 19.5 kWh (which is about 85% of the total). At the point where the FFE indicates that the battery is "empty", it still actually holds a charge of 3.5 kWh.

Do you know this for sure, about all the unavailable capacity being at "the bottom"? I haven't seen anything official from Ford, but I personally assume the FFE both saves a percentage at the bottom that is unavailable to the driver, and also saves a percentage at the top which cannot be filled. Since Ford has appeared to take a maximum battery life approach, and the FFE manual and Ford's web materials repeatedly recommend plugging in whenever possible, I wouldn't think it would be "allowed" to potentially sit long at a true 100% charge state since that's not ideal for battery life.

 

[WattsUp]

At the point where the FFE indicates that the battery is "empty", it still actually holds a charge of 3.5 kWh.

Do you know this for sure, about all the unavailable capacity being at "the bottom"?

I don't know for sure. You may be right... it is possible that the car doesn't fully charge the battery either, and the 19.5 kWh of usable charge actually occupies the "middle" of the battery's total capacity range. But, we do at least know that only 19.5 kWh of the total 23 kWh capacity is available for normal use... from a usability standpoint, it doesn't really matter whether it comes from within the battery, eh?

I guess what I should have said is that, when "0 miles" remaining is indicated, the battery has definitely been drained of 19.5 kWh worth of charge, while the remaining (potential) capacity of 3.5 kWh goes either undischarged (at the "bottom", as you put it) or simply unused (at the "top").

 

[Vach]

I'll ask around. I have a friend that works for Ford headquarters. I'm sure he can find out for me.

 

[jeffand]

The battery capacity is rated at 23 kwh. Of that 23 kwh the car uses 19.5 kwh. So FFE uses about 85% of the battery capacity.
The fact is most people will not run the battery down to less than 15 miles of range on routine basis. In my case when I get down to around 30 miles range I will plug in. For most peolpe they are not pulling into the charging station with a low battery warning.

Lithium batteries don’t like hot conditions. 100 degree weather can age the batteries more quickly. Parking in the hot sun can also create a hot environment if the car is exposed to these conditions for a long period of time. Dark colors will accelerate the heating process.
What to do? Parking in the shade will help. Park on the lowest level of a parking structure will also help. Avoid parking in a large black top parking lot. I live in Wisconsin and seeing 90 degree heat or more is very rare.

 

[blavenn]

I have a 2012 model purchased in July last year and used to have 19.5kw of usable capacity and now its dropped to about 17.5kw all of a sudden the past few months after I hit about 12k miles or so. I'm wondering if the computer has something to do with it bringing the capacity down that much since there's been updates for the car's systems since late last year. took it to the dealer to get it updated but they failed to complete the task which is a whole other story.

 

[Charged Up]

I have a 2012 model purchased in July last year and used to have 19.5kw of usable capacity and now its dropped to about 17.5kw all of a sudden the past few months after I hit about 12k miles or so. I'm wondering if the computer has something to do with it bringing the capacity down that much since there's been updates for the car's systems since late last year. took it to the dealer to get it updated but they failed to complete the task which is a whole other story.

How do you know that usable capacity has dropped?

 

[jeffand]

Cold temperatures will temporally reduce battery capacity. Repeatedly running the battery down to very low levels could age the battery faster. Prolonged exposure 90 degree plus heat will age the battery faster. More extreme temperatures can result in faster aging. I don’t think FFE is immune to the affects of heat. I just think the Focus does a better job of managing battery temperatures than the Leaf does.

Or it could be the method being used to calculating the capacity of the battery.

 

[blavenn]

my one way commute that I do once a week is about 78 miles so its a perfect test to run the ffe down to near zero when needing an accurate total energy used number. of course when there is traffic I still arrive with about 15 or so miles leftover but when I want to see the true capacity and energy being used I just drive faster.

funny thing is I was getting the 19.5kw of usable capacity during the hot summer months last year and about 17kw during the cold spell days when it would hit 50 degrees early this year. I'm down in Miami. But now that its heating up again down here I'm not getting that 19.5kw of usable capacity like I used to.