80% charge or 90% charge for daily use?

[EVPiper]

From what I'm reading, 80% is probably fine. My own experience showed life degradation with regular use above 70%. That was 5 years ago, not a Ford battery, and battery technology has improved. My rules of thumb to maximize life still apply though, the battery is likely happiest in between 40-60%. I would not recommend regularly charging to 90 and then depleting only to 70 before recharging just so you have the range 'just-in-case'. I see a comment about longer term storage at 60% and that sounds smart.

Charging strategy will vary. Personally, I have a 40-mile round-trip commute and essentially no traffic so I have little fear of a daily range issue or getting stuck in traffic. I also want to get as much life out of the battery as possible as I plan to keep it for 10 years or more. My household will maintain a traditional fuel burning vehicle for longer trips until the battery technology vastly improves.

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[Blue highway]

I get all that but the person I was quoting said he is an automotive engineer and has worked with batteries in that field. He made specific comments and I wanted to know his thoughts as to how this relates to the MME Battery.

specifically he mentioned charging to 70% normally. That is really approx 60% of MME battery.

Everything he said is directionally correct. You should take it seriously. His explanation of the difference in state of charge at 70% vs ~60% is a little dumbed down for this audience but I hope that you get the idea.

In a bit more detail, the battery pad (difference between actual state of charge and indicated state of charge) is split at the top and bottom of charge. The so what to this is that at 50% indicated and actual are pretty close. The variance between real state of charge and indicated state of charge is more like 5% at the top and 5% at the bottom of the charge. There are posts in the forum where people monitor this and share the details.

 

[SnBGC]

Considering that 90% charge is really 80% use of battery does that make a difference on first comment that 80% is ok?

90% displayed is about 86% actual.

 

[generaltso]

the on line manual says to charge less than 100% .

”You can increase the battery life by maintaining your state of charge below 100%.”

I thought at one point it said to normally charge to 90% but maybe the on line manual changed .

I also thought my car came with a paper manual but just went out to the car and there isn’t one.

It depends where you look. The 2021 Job 1 manual said 90%. That was changed for the 2021 Job 2 manual to "below 100%". Then it was changed back to 90% for the 2022 manual. I guess Ford is indecisive.

 

[daemonic3]

It depends where you look. The 2021 Job 1 manual said 90%. That was changed for the 2021 Job 2 manual to "below 100%". Then it was changed back to 90% for the 2022 manual. I guess Ford is indecisive.

I can say with below 100% confidence that they are 90% sure on their recommendation.

 

[kennethjk]

90% displayed is about 86% actual.

that’s assuming you have 91kw not 88kw useable

total KW is 99? Useable is 91 kw. 90% of 91 is 82 kw , 82/99=83% , close enough

does everyone have 91 useable now?

 

[SnBGC]

that’s assuming you have 91kw not 88kw useable

total KW is 99? Useable is 91 kw. 90% of 91 is 82 kw , 82/99=83% , close enough

does everyone have 91 useable now?

The usable amount doesn't affect it either way. The portion of the battery that is unavailable to the driver is split into two parts. The lower part remains fully charged while the upper part never get charged.

 

[kennethjk]

The usable amount doesn't affect it either way. The portion of the battery that is unavailable to the driver is split into two parts. The lower part remains fully charged while the upper part never get charged.

Interesting, thanks

 

[8Urchvy]

I only drive about 30-50 miles per week...leave it about 90% all the time... working from home now vs. a 70mile per day commute when I ordered the car.

Dumb question, but where can you set up the charging % in the settings? I should know this...but haven't cared to look.

 

[DevSecOps]

Seriously - you all act like you're gonna get an extra 100 miles out of a battery if you only charge to 80% when getting below 40%. You might get an extra 0.25 miles a year if you're lucky.

Average battery degradation has been studied intensively by companies like GEOTAB, Recurrent Auto etc. Basing your claims on YouTuber's comments and wannabe battery engineers is not a good look. They are just another Joe Bob, on the internet, with an opinion. While sure, charging habits might affect battery degradation, the question should be; by how much, and do I care?

Per the studies (1) age of battery and high temperatures are more detrimental to battery health than operating at high or low SOC, followed by DCFC after that. SOH studies by range were also crowdsourced here (2) but per study #1 are irrelevant to degradation.

The rule of thumb is every 3 months of battery age = 0.5% degradation to SOH% (per a study of 6k batteries - cited)

Using my vehicle as an example:

Battery Age: 13.305 mo
Estimated SOH: 97.7825%
Actual SOH: 97.5% (note: the MME only reports in .5% increments, so could be higher)

Difference in miles = 0.84 miles (@ 3mi/kW average)

So, me who DCFCs at least 100kW a week, nightly charges to 90/100% and never thinks twice about my battery health has lost an extra 0-0.84 miles in 13 months for doing so. I'll go with my continued, plug in and forget about it, attitude for less than a mile a year.

I think everyone here is crazy for thinking that all these different charging schemes will actually do something noticeable over your ownership of the vehicle. To be clear, I'm not claiming that there's no way to improve the battery life. Simply, the quantity of savings is minuscule and within margins of error. Y'all need to put it in perspective especially given that you have no control over the 2 most detrimental factors to battery degradation. In actuality, driving the car more is probably your best bang for buck since time is not on your side.

If you're that worried, instead of guessing, spend $25 on a OBDII reader and check it for yourself once every few months and compare it to the rule of thumb. Or subscribe to Recurrent Auto (it's free) and get a monthly battery health report.

Other things that can reduce your millage by 0.84 miles: Eating too many twinkies, aftermarket wheels, aftermarket spoilers, different tires, your dog in the car, temp changes, turning up the heater, the wind, passengers. You get the point, I hope.

 

[Howard]

I have a 160 mile round trip commute M-F with occasional short trips while at work to electrical supply stores. I charge my Select SR AWD every night S-T to 100%. When I get home each day, SOC is between 33-37% on average.

We have electric forklifts at work with Lithium Ion batteries; manufacturer told us to plug them in every night and charge them regardless of SOC. Same at previous employer as well. At previous employer, over 5 years of use, we saw no significant degradation in overall capacity.

I am retired from US Navy where I was an electrician on nuclear submarines. We had a large main storage battery (similar voltage as BEVs) which was lead acid. We cycled it nearly every single day while at sea and always charged to 100%. These batteries lasted for years. Our biggest concern wasn't over charging but discharging the battery to the point that you would start to reverse the individual battery cells. In the case of BEVs, this would be trying to drive once range gets near or at or below 0 range. My guess is this is why there is the buffer on lower end of total battery capacity. My experience with lead acid batteries is that once cells have been reversed the damage is permanent and cumulative.

I bought the car specifically for this commute. It has performed great during the two months since I got it. I agree with everyone who has said to charge the battery to match each individual's needs. Just thought I would add my thoughts to the discussion.

 

[mkhuffman]

Eh. No love for 85%. ?. Ridin the middle. Splitting the difference.
Jes sayin. How about 84. ? Or 86 ?
That’s me. Thinking out of the box ….you’re welcome.

82.6% is best because it will never damage the battery, and FP can never set the charge target for that, so you can't prove me wrong. Anything other than 82.6% will severely damage the battery.

 

[RickMachE]

It is quite amazing reading all the crazy schemes. I agree with @DevSecOps (crap), so much energy wasted on thinking about this.

Those considering Recurrent should understand that they're providing access to their FordPass account.

https://www.macheforum.com/site/thr...or-battery-degradation-study.6289/post-287861

 

[Larry Paul]

For the first 3K miles or so I would charge to 80% most of the time and occasionally to 85%. Since around then for our daily use we only charge to 70%. My routine driving consumes 10-20% of the pack. Rarely, but occasionally I will consume 30-40% for daily driving. I typically recharge daily back to 70% reported SOC.

(Before my only road trip I charged once to a reported 90% reported SOC before I departed, but not above 75% from the one time I used DCFC. )

 

[Ming]

I've heard Elon Musk keeps his Tesla at 69%.

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