Is My Battery Degrading?

[DanCoon]

I have exactly 12,600 miles on my standard range Mach-E that I've had since March. I've noticed for the past week that the battery only charges to 89% instead of the 90% I have it set at. This is with the Ford Mobile Charger in the garage.

I didn't think much of it until I ran an errand this morning and noticed that the battery percentage went from 89% down to 84% over the course of 3 miles. It's only 65 degrees over here in Sacramento and I checked the trip computer, which showed that 100% of the charge was for range during those 3 miles.

Is this the early signs of battery degredation, or does the charge % also act as a GOM and should only be taken with a grain of salt?

Sponsored

 

[gafear]

That invites a good question - is it possible to truly measure the degradation? In case it goes over the 30% threshold to yield a warranty claim?

 

[benk016]

I have exactly 12,600 miles on my standard range Mach-E that I've had since March. I've noticed for the past week that the battery only charges to 89% instead of the 90% I have it set at. This is with the Ford Mobile Charger in the garage.

I didn't think much of it until I ran an errand this morning and noticed that the battery percentage went from 89% down to 84% over the course of 3 miles. It's only 65 degrees over here in Sacramento and I checked the trip computer, which showed that 100% of the charge was for range during those 3 miles.

Is this the early signs of battery degredation, or does the charge % also act as a GOM and should only be taken with a grain of salt?

Does your car get done charging a long time before you actually drive it? Mine will get to 90% at like 12:45am, and then if I don't actually go to drive it until the next day sometime, my SoC will drop a lot faster than if It had just finished charging.

If I charge to 90% and then drive immediately, it will drop down normally. But if its sat for a while after charging, those first few % drop down really fast.

I have a feeling the car isn't taking into account any conditioning, or 12v charging it did while it was off, plus just the car losing charge as it sits, and then when you start to drive it realizes its a little lower than it was when it was last on. That is just my theory anyway.

Using OBD data, I've got a calculation of battery health. Currently my extended range shows that my actual useable capacity is 88.3kwh.

 

[bshaw]

How many charging sessions over the 12k miles have you used a DCFC vs. the at-home Ford mobile charger?

Shouldn't cause what you are seeing, but would be another datapoint.

 

[DanCoon]

Does your car get done charging a long time before you actually drive it? Mine will get to 90% at like 12:45am, and then if I don't actually go to drive it until the next day sometime, my SoC will drop a lot faster than if It had just finished charging.

If I charge to 90% and then drive immediately, it will drop down normally. But if its sat for a while after charging, those first few % drop down really fast.

I have a feeling the car isn't taking into account any conditioning, or 12v charging it did while it was off, plus just the car losing charge as it sits, and then when you start to drive it realizes its a little lower than it was when it was last on. That is just my theory anyway.

Using OBD data, I've got a calculation of battery health. Currently my extended range shows that my actual useable capacity is 88.3kwh.

No, my car is usually fully charged about 30 minutes before I leave for work, and depending on the state of charge sometimes I won't be able to finish by the time I take off for work. I have it set to charge from 11pm.

I haven't checked any OBDII data yet, but I will this weekend and let you know.

As far as the DC charging, as another member asked.... I would say I DC charge to top off maybe once a month to get a 10% or 15% I need to get home. Outside of that I DC charged only during that 2200 mile road trip last month.

 

[kevC]

I just got my car and I've noticed that it goes immediately to 89% as soon as I drive it after charging it to 90%. I just assumed that it literally charges to 90.0000% then the display doesn't round up so it drops to 89%?

 

[DYohn]

Battery degradation is not likely. More likely is just the strange behavior of the GOM software.

 

[benk016]

I just got my car and I've noticed that it goes immediately to 89% as soon as I drive it after charging it to 90%. I just assumed that it literally charges to 90.0000% then the display doesn't round up so it drops to 89%?

This is also likely part of it. Using OBD you can see the SoC displayed as like 90.5% but the car only shows 90% So if it stops right at 90.0% its not going to take much to drop down to displaying 89%

 

[Eraser]

I have exactly 12,600 miles on my standard range Mach-E that I've had since March. I've noticed for the past week that the battery only charges to 89% instead of the 90% I have it set at. This is with the Ford Mobile Charger in the garage.

I didn't think much of it until I ran an errand this morning and noticed that the battery percentage went from 89% down to 84% over the course of 3 miles. It's only 65 degrees over here in Sacramento and I checked the trip computer, which showed that 100% of the charge was for range during those 3 miles.

Is this the early signs of battery degredation, or does the charge % also act as a GOM and should only be taken with a grain of salt?

I've noticed the exact same issue. My charging is finished in the early morning then I leave around 6-7 hours later. I have just over 5k miles on my SR. I highly doubt there is any battery degradation this early on for any of us. I agree with @kevC.

 

[zhackwyatt]

Battery degradation is not likely. More likely is just the strange behavior of the GOM software.

I don't know about that. Most degrade a little bit in the beginning and then taper off and dont degrade much at all (unless the battery is getting extreme conditions all the time).

 

[jlauro]

Going to 89% fast, wouldn't worry about, but an additional 5% in 3 miles doesn't sound so good. That is well beyond normal degradation this soon, but I wouldn't rule out a bad cell or something...

Any chance you are going up hill on those 3 miles? Maybe make a round trip as you should get much of the extra energy back or saved on the way back if extra was used on a slight incline for those 3 miles.

 

[DYohn]

I don't know about that. Most degrade a little bit in the beginning and then taper off and dont degrade much at all (unless the battery is getting extreme conditions all the time).

You have evidence for that? Most studies I've read indicate that battery degradation takes many years to appear. Overcharging can exacerbate it.

 

[breeves002]

Keep in mind indicated SoC and real SoC can be different and vary for multiple reasons. From brand new multiple times I have had mine only charge to 79% instead of the 80% I had it set at. There doesn't seem to be any rhyme or reason to it.

Also if the e-heat is on at 65 degrees it will run to heat the coolant up which can take a little bit of power.

I wouldn't freak out about it. If an extended drive nets about expected results than it is fine.

 

[jlauro]

Have you taken any medium length trips? What the battery like after at least 50 miles?

 

[DanCoon]

Going to 89% fast, wouldn't worry about, but an additional 5% in 3 miles doesn't sound so good. That is well beyond normal degradation this soon, but I wouldn't rule out a bad cell or something...

Any chance you are going up hill on those 3 miles? Maybe make a round trip as you should get much of the extra energy back or saved on the way back if extra was used on a slight incline for those 3 miles.

All level. I take that route every day and thought it was strange that there was a 5% drop rather than the usual 2% I've experienced before. I'll keep an eye on it this weekend.

Sponsored