Battery Degradation

[Texas FFE]

Last time I measured my battery capacity I only got a 16.7 kWh capacity measurement and I have just over 38,000 miles on my 2013 FFE.

The Nissan Leaf battery warranty allows up to 70% battery degradation for up to 5 yrs/60,000. In the case of the FFE, the measured battery capacity would have to drop below ~14 kWh (20*0.7) to be considered significant battery degradation. Regarding this information my 16.7 kWh measured battery capacity does not look too bad.

About a year ago I performed a bunch of real world driving test to determine my range at various speeds before taken a cross country trip in my FFE. I didn't know about the trip meter test we have been talking about here but my highest capacity test indicated 15.9 kWh with 5% remaining. So it doesn't appear that I have had significant battery degradation over the last year.

If there becomes a 30 kWh battery upgrade available, either though Ford or aftermarket, I'm going to upgrade my battery as soon as my measured battery capacity drops below 14 kWh, whether or not it's still under warranty. If no battery upgrade becomes available, I'm not going to replace my battery until the measured battery capacity falls below 50% or ~10 kWh. From the graphs I've seen of battery degradation it appears that battery degradation tends to level off after the first couple of years so it may be many, many years before I replace my battery.

 

[michael]

The Volt has a battery capacity of 18.4 kWh, of which 14 kWh is usable. A battery electric vehicle with 14 kWh is crippled. Mine is down to 15.2 kWh usable and it is significantly compromised, I'm glad it's going back at lease end. It barely gets me to work on cold days, it would be unusable in another winter.

My experience has not supported the expectation that battery fade levels off. I have seen a steady decrease over 52,000 miles. In fact, when you think about it, as the battery become effectively smaller, more and more depth of discharge is needed for the same distance, thus further stressing the battery.

The Nissan battery replacement policy should not be used as a gauge of good and normal. It was their "throw a bone" response to a significant battery fade problem.

 

[mikey7mc]

I've given up fighting Ford regarding my FFE. The reality is that the car gets between 50 and 55 miles per charge here in Phoenix, AZ in the dead of summer. The climate control system pulls way too much battery power and negates the 74 miles per charge guess-o-meter. Ford says everything is functioning as design. It is a bad design. Between the battery coolant system, climate control and driving in 110 degree temps, the FFE needs driving modes similar to the i3 so that power conservation is an option. I have the same troubles in the winter when the exterior temps are below 40. Thankfully that doesn't happen often in Phoenix, but I can only imagine what some of you are going through in cooler climates, especially in winter.

I have 6 months left on my lease, about a month more of hot weather. Just riding out this vehicle and switching to an i3 then a Tesla model 3.

 

[Jamez]

The big problem is that Ford has yet to adopt the degradation warranty.

We all know they're just dragging their feet making the FFE anyway, but Ford won't be considered a player in the EV market until they do (and stand behind their products).

...Still, pretty damn good little car for dragging their feet...

 

[Jamez]

There were some very good posts on this forum regarding how to check the battery capacity. Basically you fully charge the battery then you reset the trip meter so the kWh reading zeros out. Then you drain the battery completely until the green Ready-to-Drive icon turns off and read your current battery capacity as kWh on the trip meter.

You can drain your battery any way you like but you probably want to be siting next to a charger when the Ready-to-Drive icon goes off because the car is not going anywhere on its' own. Using the 6kW Defrost feature with the rear window defroster turned off will suck down the last few kWh quickly while the car is siting still. Most people are reporting capacity measurements in the middle 17 kWh range but some people are reporting as high as 19 kWh.

Can we get someone with a brand new 2016 FFE perform this test so we can get a benchmark for degradation?

Mine is less than a week old. Let me know how you'd like me to test...

 

[michael]

Completely charge the battery. Do this on a moderate temperature day so that the battery will be at normal operating temperature but not require much cooling.

Start the car, open the windows, reset the trip meter

Run the heater at full blast (max temperature, full fan). Note the trip meter readings periodically (Half hour or more often if not too inconvenient). Note the trip meter reading when the car says battery exhausted.

With the heater full blast, it consumes about 6 kW, so the test will take roughly 3 hours.

 

[Jamez]

Okeedokie Test completed. I hope I did it right and provided you with the information you are looking for

20.4kWh across 3:39:09

The car was built July 28, 2016 and has 747kms on it.

For those of you with FaceBook you can see the image below (if the image is working, or check the other link). I have images taken apx every 30 mins. If someone feels they want to see the images (perhaps to graph the drop), let me know and I'll post them.

https://www.facebook.com/myevlife/photos/a.151309605301315.1073741828.151297301969212/165919083840367/?type=3

 

[michael]

Great job!!!!!

We finally have a good starting point for a recent model with little use. Everyone can use this for reference in the future.

3 1/2 hours at 6 kW, just as expected.

 

[Jamez]

Now if we could only get Ford to accept that a vehicle with a shrinking fuel tank is not a good thing for the long term we'll come out ahead.

Come on Ford - get with your competition and adopt a battery degradation percentage for a replacement warranty!!

 

[michael]

The best solution to battery fade is to provide an overlarge battery and stress it lightly. Then the manufacturer can reasonably put a warranty against fade because it will not be unavoidable, but rather will occur only in case of a defect.

It would be cheaper for the manufacturer to supply a 30 kWh battery that lasts than to need to replace a 25 kWh battery