FFE owners +1 years or more: Any loss of battery capacity?

[studio460]

I have a 60-mile, round-trip commute which includes one significant incline. I've been concerned that if in year x, my capacity is reduced by say, 30%, that may severely impact my commute. Does anyone have any data on their batteries +1 years in? Thanks!

 

[jmueller065]

I'm 13 months in, 13,000 miles and have not seen any significant battery loss. Making all the same trips this summer that I did last summer with the same (or in some instances more) amount of battery remaining.

 

[hybridbear]

I have a 60-mile, round-trip commute which includes one significant incline. I've been concerned that if in year x, my capacity is reduced by say, 30%, that may severely impact my commute. Does anyone have any data on their batteries +1 years in? Thanks!

Our FFE was built in November 2012. It was originally leased in August 2013 and the original lessee only drove it 4200 miles in 11 months before we took over the lease. This past week I did a long trip as referenced here: http://www.myfocuselectric.com/forum/viewtopic.php?f=14&t=1971&start=60#p12487

I used 17.8 kWh (according to the trip meter) and the battery indicated that the SOC was about 12% after that. There doesn't seem to be any capacity loss. And our FFE likely sat a long time at the dealer without being driven much and the original lessee drove very little and mostly left the car sitting fully charged.

 

[jachady]

I have been in mine for just over a year and have 12000 miles on it. I don't see any change in the battery capacity by the seat of my pants. We can travel where we always did and we still end up with 100+ range in the morning. If the capacity drops, I think that learning the proper way to drive the car negates any drop.

However, on a different note. When I jump in brand new ones at the dealership with their first full charge, there is a noticeable difference in power.

 

[danholl]

2 years, 20,000+ miles - no apparent loss of battery capacity

 

[WattsUp]

2 years, 20,000+ miles - no apparent loss of battery capacity

Same here after about 1.5 years, 20,000+ miles. I'm still making all the near-limit trips I'm used to making. I do a 50/50 of freeway/city driving almost every day. The car still routinely estimates over 80 miles range.

That said, I do live in a mild climate, which obviously helps with battery performance. I charge the car almost every day... most of the from at or above the 50% mark. On weekends, the battery often gets drained much lower. A couple times a month, I happen to take a near-limit trip, taking the battery to near 0%.

It's possible that there might be some slowly-progressing, hard-to-notice loss, like 1% or something (and probably is since that is simply the reality with Li-ions), but I personally have no sense that the battery has yet lost any capacity.

 

[mcowger]

2 years, 20,000+ miles - no apparent loss of battery capacity

Same here after about 1.5 years, 20,000+ miles. I'm still making all the near-limit trips I'm used to making. I do a 50/50 of freeway/city driving almost every day. The car still routinely estimates over 80 miles range.

That said, I do live in a mild climate, which obviously helps with battery performance. I charge the car almost every day... most of the from at or above the 50% mark. On weekends, the battery often gets drained much lower. A couple times a month, I happen to take a near-limit trip, taking the battery to near 0%.

It's possible that there might be some slowly-progressing, hard-to-notice loss, like 1% or something (and probably is since that is simply the reality with Li-ions), but I personally have no sense that the battery has yet lost any capacity.

What happens when you get that low. The lowest I've been to is 10mi remaining and the car bonged and turned the battery icon orange.

When it hits 0 does the car stop, or is there some reserve left, etc?

 

[unplugged]

When it hits 0 does the car stop, or is there some reserve left, etc?

Nope. No reserve. It pretty much just says, "Battery Depleted". Then the computer lady comes on and says, "You idiot, we told you it was going to stop!" Okay, maybe not the last part. But there really is no reserve that I've experienced. I have run it down to 3 or 4 miles remaining many times. (I pretty much have become an expert at judging how far I can go on a full or partial charge.) But only drained it once. In my garage. Just to see how much battery it used.

 

[WattsUp]

When it hits 0 does the car stop, or is there some reserve left, etc?

Nope. No reserve. It pretty much just says, "Battery Depleted". Then the computer lady comes on and says, "You idiot, we told you it was going to stop!" Okay, maybe not the last part. But there really is no reserve that I've experienced. I have run it down to 3 or 4 miles remaining many times. (I pretty much have become an expert at judging how far I can go on a full or partial charge.) But only drained it once. In my garage. Just to see how much battery it used.

I admit, I've never actually drained it to the point of the car shutting down. When I say "near-limit", I mean arriving home with under 5 miles remaining, sometimes as low as 1 or 2.

Once, I arrived home with the car actually popping up a "battery depleted" warning, with the range saying 0 miles and the battery percent saying 0%. I must have timed it just right, as I still had power to pull down my street and into the garage with the warning still showing. I don't know how much longer the car would have lasted. I knew it was going to be close, and had to really slow down for the last several miles. Luckily, it was late at night, with nobody really around to mind that I was doing 20 mph.

So, the car doesn't necessarily stop dead the moment the warning pops up, but I would assume that whenever it says "battery depleted", you probably have only hundreds of feet of range left at best.

 

[studio460]

Thanks for everyone's replies. I guess it's just too early to tell how much we'll lose in years 5-8. Again, using my camera battery analogy--they seem to start losing capacity at around five years (I'm guessing 15%-20%--but that's sheer guesswork), and will reach EOL anywhere from five to eight years. About one in four batteries lost significant capacity in the first two years (which were out-of-warranty, and which we simply replaced at our own expense).

 

[WattsUp]

Thanks for everyone's replies. I guess it's just too early to tell how much we'll lose in years 5-8. Again, using my camera battery analogy--they seem to start losing capacity at around five years (I'm guessing 15%-20%--but that's sheer guesswork), and will reach EOL anywhere from five to eight years. About one in four batteries lost significant capacity in the first two years (which were out-of-warranty, and which we simply replaced at our own expense).

It may not be a fair comparison. I think the car's many li-ion cells are collectively treated more "carefully" that the poor lone cell (or few cells) in a camera or phone battery. The car's battery temperature is kept (for the most part) in the stable range, the are never charged to the limit, etc.. As far the life of a the typical rechargeable battery (in a consumer device, as you reference) is concerned, the cells in an EV are treated rather nicely, and I think will last correspondingly longer.

But, yes, we'll all just guessing. We're the early adopters.

 

[hybridbear]

Thanks for everyone's replies. I guess it's just too early to tell how much we'll lose in years 5-8. Again, using my camera battery analogy--they seem to start losing capacity at around five years (I'm guessing 15%-20%--but that's sheer guesswork), and will reach EOL anywhere from five to eight years. About one in four batteries lost significant capacity in the first two years (which were out-of-warranty, and which we simply replaced at our own expense).

I agree with Wattsup. The FFE manages battery temp very carefully and doesn't allow us to fully charge or fully discharge the battery. I don't know how the camera batteries work, but they likely don't have much of a safety margin at the top or bottom when charging.

Also, remember how the batteries in hybrids have proven extremely reliable. I believe Toyota brags that well under 1% of Prius batteries have to be replaced over the life of the car. Usually the body will rust away before the battery dies. I know that those batteries aren't the same as in an EV, but they provide a reference point. The automakers have been careful because they don't want to make unreliable cars. Nissan tried to make an EV as cheaply as possible so that they could turn a profit on it and thus skipped things like liquid cooling and it has hurt them in hot climates. Ford seems more interested in using the FFE as a test car to gather data about real world use through MFM and other means and is not concerned with making a profit on the FFE so they built a more expensive car. Chevy went to the extreme with the Volt of battery protection and has had great success with Volt battery longevity.

I don't recall reading anything published by Ford about the HVB development for the FFE, but when talking about their 2013+ hybrid & Energi vehicles there was a press release about how they tested the new battery design & chemistry over the equivalent of 100,000 miles to ensure that there would be no change in how the battery behaves after 100,000 miles. One of the engineers was quoted as saying something along the lines of, "The body will rust away before the battery needs replacing."

 

[v_traveller]

Just another data point: No noticeable battery degradation after 17 months/21,000 miles.

It is charged 2x/day when used, typically I drive the FFE to work 3x-4x/week. Battery is depleted about 40%-45% going to work, charged to 100% on L2, then depleted about 65%-70% going home. It is then charged overnight at L1 to 75%-100% before starting the cycle over the next morning.

 

[dmen]

It's possible that there might be some slowly-progressing, hard-to-notice loss, like 1% or something (and probably is since that is simply the reality with Li-ions), but I personally have no sense that the battery has yet lost any capacity.

I agree. This car can't defy the laws of chemistry/physics/whatever dictates battery behavior. Loss of capacity is guaranteed. I think it has to be more than 1% after 10000 miles in even the most carefully temp-managed/charged/driven EV per theoretical graphs I've seen on plugincars.com or battery university or somewhere, but the point is that it's not noticeable in daily driving because no one who knows what they are doing would get an EV with a range that just barely meets their needs. Plus none of us knew how to drive an EV for max range at first, so the range we thought was just barely doable when we took it on its first tests, is actually completely, easily doable. So we can still do all the same drives we did 1 or 2 years ago, and might not notice the battery's now at 40% instead of 43% when we plug in for the night. I believe many leaf owners with a bar or two missing would have no idea their car had less battery capacity if it wasn't staring down at them from the dashboard.

I don't have a scanner but I'm tracking energy displayed on trip meter for a full discharge periodically. I measured 19.8 kWh with about 5000 miles on it last summer around 75F, and 18.6 kWh with about 11000 miles on it in April around 60F. Temp differences make it hard to directly compare the two numbers; I'll do it again sometime this summer to get a better comparison. Others here have questioned the accuracy of the trip meter measurement, but I believe if nothing else it should be consistent so that differences over time are meaningful.