Fast charging more than 80% degrades battery?

[chandwawar]

I know. I was planning to put 3500lbs on the trailer, because the guy I borrowed it from told me that's what it supported. Once I got to look at it though, it was apparent the trailer tires were rated much lower and couldn't support that.

Yes I have the onboard scale. I found last week, while hauling 45 bags of concrete, that it maxes out at 1750lbs. The fork lift driver couldn't get the load in front of the rear axle. Talk about a dangerous load, it felt like the front wheels were lifted off the ground. Anything over 50 mph and it would weave all over the road.

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[RickLightning]

I know. I was planning to put 3500lbs on the trailer, because the guy I borrowed it from told me that's what it supported. Once I got to look at it though, it was apparent the trailer tires were rated much lower and couldn't support that.

Yes I have the onboard scale. I found last week, while hauling 45 bags of concrete, that it maxes out at 1750lbs. The fork lift driver couldn't get the load in front of the rear axle. Talk about a dangerous load, it felt like the front wheels were lifted off the ground. Anything over 50 mph and it would weave all over the road.

It maxes out because that's your PAYLOAD LIMIT. So you have the scale, which shows you your payload limit, which told you that you were overweight, at least twice, and you do it anyway?

Wow. Oh, never mind. I just saw you're in Minnesota. I don't go there, so do what you want, you can't kill me on the road when you lose control.

 

[Nikos]

I'm on a trip towing 5,000lbs today and need as much range as possible, but I noticed that the Fordpass app recommends only fast charging to 80% or else battery life could be degraded. Is it hype or a recommendation we should all try to obey?

Get it to 90% if you can. The truck will try to keep the charge at around 50KW rate between 80-87%.
Some stations will cut you off at 90%.
No worries about the battery. If the temps are above 65° then you are doing fine.

 

[ExCivilian]

Yep. On the FAQ for the Lightning it says for everyday driving to charge to 90%.

https://www.ford.com/support/how-to...ightning-charging-frequently-asked-questions/

I don't know why Ford wrote this in the way they did but charging to 90% doesn't "prolong the life of the battery"--charging to less than 100% prolongs the battery life but there isn't anything special about 90% specifically. Charging to less than 100% is easier on the battery the less you charge (90 is better than 100, 80 is better than 90, and 70 is better than 80, etc.).

The way they wrote it, and a number of people seem to be interpreting it, implies there's something special about 90%. Then Ford hardcoded the charge limit to 90% for DCFC for some reason. It should have been set to 80% (the excess battery cells notwithstanding) but far more importantly it shouldn't be hardcoded at all, imo. Keep in mind that hard setting only applies to DCFC. The charging settings for L1/L2 are elsewhere. You have to first start charging at your non-DCFC station for it to show up in the settings then you can adjust the charge level and charging windows.

 

[Jim Lewis]

I don't know why Ford wrote this in the way they did, but charging to 90% doesn't "prolong the life of the battery

There's the facts of EV life. Lithium-Ion Battery Care Guide: Summary Of Battery Best Practices - CleanTechnica. Then there's the need to sell EVs. Unfortunately, AFAIK, Ford is not as upfront about Li-ion battery life as a company like Apple is. Apple has web pages that lay out in detail the care and feeding of Li-ion batteries and start out by declaring it's a consumable that's going to be used up someday and gives you an idea of how many equivalent full-charge cycles you can expect a particular product to last. Apple also includes a battery health indicator in iOS settings. Ford has much of that implied throughout the truck manual but then comes up with statements like the one you cited that recommend that you charge to 90% every day for everyday driving (which is really 82% SOC relative to the true 143 kWh ER battery capacity).

I think the bottom line is they don't want you to feel inhibited or limited in opting for an EV over an ICE vehicle. Charging to 90% every day will easily get you through your warranty period, eight years/100,000 @ >70% battery capacity remaining. They won't have a warranty claim, and you won't have range anxiety (until you start to really wear out your battery, a very slow process!). OTH, if you live in colder climes and manage to lower your battery capacity towards 70% remaining capacity, you will certainly suffer range anxiety in winter because 70% remaining capacity x 70% of full charge in cold winter weather equates to only 50% effective range when your battery's old and it's cold outside.

Here's a summary of what Darren Palmer, the Ford e Division VP, had to say about charging and warranty period considerations by Ford. He certainly states you'll do better if you don't fast charge regularly and you stay between 20% and 80% SOC. Then there's Ford's PR Department... Depth of discharge affects Li-ion longevity, but it's a hassle to mind that parameter for folks who drive a lot.

Tom Moloughney, on his State of Charge YouTube channel, has an interview with Darren Palmer, VP of the electric vehicles division at Ford. Palmer says that Ford didn't want to end up paying for replacement batteries under warranty. Their warranty of 8 years or 100K miles, whichever comes first, while still having at least 70% SOC capacity left in the battery, is designed to be met if the user charges EVERY DAY to 100% with a level 2 charger. IIRC, Palmer says in the interview if you stay within the 20% to 80% SOC, you'll do far, far better than that. So, reducing the charge rate to something less than 80 amps with the FCSP will just be more icing on the cake if you charge almost entirely at home.



(warranty segment starts at about 28:18 into the video)

 

[MickeyAO]

I think I read on these forums that a guy who has actually tested Li-ion cells and EV packs for the last 12 years only charges his personal Lightning up to 85% SOC on a daily basis...something about being in the meat of the delta SOC and more than he needs for daily driving.

He might have mentioned something about charge rates too.

 

[astricklin]

This is why I kinda wish Ford had already changed over to lfp on the sr packs.

 

[Zprime29]

I know. I was planning to put 3500lbs on the trailer, because the guy I borrowed it from told me that's what it supported. Once I got to look at it though, it was apparent the trailer tires were rated much lower and couldn't support that.

Yes I have the onboard scale. I found last week, while hauling 45 bags of concrete, that it maxes out at 1750lbs. The fork lift driver couldn't get the load in front of the rear axle. Talk about a dangerous load, it felt like the front wheels were lifted off the ground. Anything over 50 mph and it would weave all over the road.

I hope you at least put your hazards on. Knowing you are overloaded, it's common courtesy to let other drivers know there is a hazard. (like those pickups you see piled 20ft with furniture)

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