Question about real battery capacity, charging to “100%” (notice the quotes)

[ctuan13]

I really don't want to, but I do have to refute the 90% AC vs DC is no different. There is a world of difference based on the current levels used.

@PreservedSwine if you want to know how to make the cells last virtually forever, find the guy that runs the Energy Storage Technology Center, read all his post of 12 years of hands on testing and data. Should take a couple of hours to get through them all.

BTW, I do not follow his advice on acceleration, but I do on SOC levels.

Yeah, someone should really pin that guy's posts and make them easily searchable. He seems to really know his stuff!

Sponsored

 

[Yellow Buddy]

Yes it did and I have the data to prove it based on the chemistry. You just won't see it for a couple of years of doing this but you are accelerating the aging process.

BTW, we just started putting the Lightning cells under test, so if you see me selling my truck before my normal 3 years, you will know I found something I didn't like!

Guess catastrophic was the word I was thinking of. The car still drives and getting full range right now.

 

[MickeyAO]

Guess catastrophic was the word I was thinking of. The car still drives and getting full range right now.

It won't be catastrophic unless you had unbalanced cells, but you are accelerating the aging process.

What are the dangers of unbalanced cells? If you have one above the mean voltage, as you charge the pack, it could cause that cell to go over the maximum voltage, which might lead to venting or at worst, thermal runaway (we do this ALL the time when testing cells, modules, and packs)

Possible good news is we could not induce thermal prorogation in a Mach E module when the cooling system was running. We overheated a cell, saw it vent, and then nothing. Then we overcharged a cell in the same module, watched it vent, then nothing. One of the few times I have not induced thermal runaway propagation in a module.

Don't know what we are going to do to the Lightning module we have left...probably a nail penetration since it is a sealed module.

 

[Maxx]

What are the dangers of unbalanced cells?

Do you know when and how Lightening balances cells? Do I need to charge to 100% periodically to help that process?

Anything other than manufacturing flaws that can result in some cells go over acceptable nominal voltage?

 

[Maxx]

To help the pack longevity, I try to minimize the area under the curve:

Y = Abs (SOC%-50)
X = Time

keepin it cool and keepin it real helps too.

 

[SMMD]

@MickeyAO - are you able to be a little less obscure about how we might be able to access the posts of “the guy who runs the Energy Storage Technology Center”? Is that you? Is it your boss? A name, or a link might be helpful to find these posts if you are able to provide. I think they would make fascinating reading. Thx.

 

[ctuan13]

@MickeyAO - are you able to be a little less obscure about how we might be able to access the posts of “the guy who runs the Energy Storage Technology Center”? Is that you? Is it your boss? A name, or a link might be helpful to find these posts if you are able to provide. I think they would make fascinating reading. Thx.

It's him and if you search for his name on the forum you'll find countless posts he's made with invaluable info and guidelines on how to maximize pack life and health.

 

[Jim Lewis]

To help the pack longevity, I try to minimize the area under the curve:

Y = Abs (SOC%-50)
X = Time

You might want to minimize Y (depth of discharge) but if you minimize X (charging time?), you'll be putting more amps (and more heat) into the battery in a shorter amount of time.

Perhaps you mean to imply in minimizing X the amount of time the battery spends away from 50% SOC???

 

[GDN]

Yes it did and I have the data to prove it based on the chemistry. You just won't see it for a couple of years of doing this but you are accelerating the aging process.

BTW, we just started putting the Lightning cells under test, so if you see me selling my truck before my normal 3 years, you will know I found something I didn't like!

I have this weird feeling with the 2 major problems we've already seen from these batteries we need to be watching this very closely. (2 problems being Fire of a truck with `19 problems and the ongoing 4% of the battery issues which can leave you stranded at most any time.)

 

[GDN]

It won't be catastrophic unless you had unbalanced cells, but you are accelerating the aging process.

What are the dangers of unbalanced cells? If you have one above the mean voltage, as you charge the pack, it could cause that cell to go over the maximum voltage, which might lead to venting or at worst, thermal runaway (we do this ALL the time when testing cells, modules, and packs)

Possible good news is we could not induce thermal prorogation in a Mach E module when the cooling system was running. We overheated a cell, saw it vent, and then nothing. Then we overcharged a cell in the same module, watched it vent, then nothing. One of the few times I have not induced thermal runaway propagation in a module.

Don't know what we are going to do to the Lightning module we have left...probably a nail penetration since it is a sealed module.

It's likely nice to see Mach E info reported, but aren't the MachE batteries as different to our trucks as a Tesla battery is? Different manufactures, composition, etc?

 

[MickeyAO]

It's likely nice to see Mach E info reported, but aren't the MachE batteries as different to our trucks as a Tesla battery is? Different manufactures, composition, etc?

Different manufacturers, but same chemistry and form factor (NMC and pouch). The Tesla cells have a completely different chemistry (NCA and cylindrical).

 

[Maxx]

Perhaps you mean to imply in minimizing X the amount of time the battery spends away from 50% SOC???

I do mean minimizing the time battery spend away from 50%. Spending a day at 100% being a lot worse than spending two days at 45%.

X is the life time of the battery starting from the day the pack was built and moves at a constant speed (Hopfully Einstein is not listening). The higher the charge or discharge (absolute Y) and the longer it stays there, the larger the area under the curve.

I guess I should have said Minimize area under the curve for a given time. Because as we extend the life of the battery, that area increases too. I just tried to put it on a shorter form. We are generally on the same page.

 

[RonTCat]

Do you know when and how Lightening balances cells? Do I need to charge to 100% periodically to help that process?

Anything other than manufacturing flaws that can result in some cells go over acceptable nominal voltage?

You have to charge over 80%.

 

[ryun]

I use the truck as a work truck, and need as many miles as I get get (some days)

I think that's your answer right there. If you need 100% then charge to 100%. It's awesome you're using your truck for work but the truck has gotta work for you versus the other way around, y'know?

If you can make 90% or even 95% work then those would be better for longevity. Don't forget that Ford warranties the battery for at least 70% of original capacity over 8 years/100K miles too.

 

[flux capacitor]

There is all kinds of miss information and myths about EV Batteries. I found this youtube video I think explains how to get the most and longest life out of you battery.

The Truth about EV Battery Life and Charging Best Practice.

I have begun treating my Lightning like my iphone with the exception of charging to only 85%. I find that a happy medium between 90% where the charger starts reducing the rate of charge and greater than 80% so I get 255- 267 mile estimated range (extended battery). You will not know what your real range is until you drive it a good amount of miles and work in your own driving habits. If you are more of an aggressive driver like fast off the line, a lead footer, use a lot of accessories you will experience less range. If you are more conservative and take off the line gradually, drive lower speeds, limit your accessories you will extend your range. Lots of aggressive driving creates heat and you will see in the video heat is the worst enemy in degradation of your battery.

If you compare that to a gas vehicle you have the same problem with range. You can watch your tank level go down fast if hop on it all the time and watch your engine temperature go up, but you can make that tank of gas last a lot longer if you are more conservative driver.

Talk to much on your phone and constantly using Apps your battery will go down fast.

Once you get use to it its no big deal and the freedom of waking up to drive and over night your truck is ready to go. How many times have you gotten in your gas vehicle and found it close to empty when you don't have the time to go get gas.

Sponsored