Top battery off to 90% every day?

[John Becker]

Do you @MickeyAO have any information (or just an educated guess) how much L1 vs L2 charging would add to SOH? Or the difference between L2 40 Amps and 16 Amps?
My uneducated guess is that the difference in SOH would be minimal if statistically significant at all.

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[MickeyAO]

Do you @MickeyAO have any information (or just an educated guess) how much L1 vs L2 charging would add to SOH? Or the difference between L2 40 Amps and 16 Amps?
My uneducated guess is that the difference in SOH would be minimal if statistically significant at all.

I cannot share or expound on the data we collected on the charge curves for L1, 3 different settings for L2, or all the DCFC curves when we tested a SR Lightning. Your company would have to join the EVESE consortium to obtain the data...I doubt they would want to pay the $75k/year just for this information.

 

[mr.Magoo]

So all this talk has me wondering...

How much of this is a realistic/practical concern for anyone ?

How bad could it possibly get during a time span of, say 5, 10, 15 years ? How many of you plan on keeping you truck for 10+ years?

Is this mostly a theoretical exercise that in the end only will benefit the 2nd hand buyer ?
Will Ford / the industry adjust the trade-in value based on SoH ?

Don't get me wrong, I too do have a profile pic of MickeyAO on my bedside table, the guy know what he talks about and we all can agree that charging behavior will affect battery life / performance, but, the question still remains - for the majority of us, does it really matter ?

 

[Jim Lewis]

How bad could it possibly get during a time span of, say 5, 10, 15 years ?

I think if you really wanted to find out, you'd have to DC fast charge to 100% every day, drive enough each day to discharge to around 10% SOC or lower, live in the American Southwest (say Phoenix, AZ), and love to park much of the day on hot asphalt lots in the open sun. Whenever getting on the Interstate or any similar high-speed highway, be sure to floor it and try to make 60 in under 4 seconds. Sometimes, 20 or 30 miles of range can make a difference as to whether you make it to the next charger, and what looks like a little bit of range loss can sometimes make a significant difference. That's been bantered about on the forum: always stay as charged up as possible because you never know when you'll need all that charge in a pickle. One might say: maintain as much battery capacity as possible, as you never know when you'll need as much capacity as you've got. High-speed driving and cold multiplicatively take away, too, from whatever capacity you've got left. And if it's like the iPhone BatteryGate, will Ford mimic Apple and restrict motor power output as you approach 70% capacity so you don't crap out on power output if you demand too much of your battery when it's aged? (Apple was infamous for restricting aged iPhone performance when battery capacity approached 80% to avoid system crashes if a user overtaxed their iPhone; cynics saw it as a scheme to induce the user to buy a new phone). Hopefully, before too many years have passed, we'll all be able to see where each of our trucks is going in battery capacity and performance and adjust our habits accordingly (or sell our trucks) if we can't live with where we're headed for the way we like to live and drive. I find all the stuff about Ford battery module replacement more discouraging for the future than any thoughts of general Li-ion chemistry and "model" behavior recommendations. Likely to have a bigger effect on resale value, too, if the battery module stuff is a long-term ongoing thing...

 

[TaxmanHog]

How bad could it possibly get during a time span of, say 5, 10, 15 years ? How many of you plan on keeping you truck for 10+ years?

I'm averaging 8-10 years on vehicles, so extra efforts to protect the battery are worth it to me.

 

[TaxmanHog]

As @Maquis says above you are thinking of DC. You start to lose time when the truck is requesting less than the equipment can supply. That happens a lot sooner when there is 100 kW or more available on DC. The curve below shows my last 100% charge on an SR battery using a 48A (11.5 kW) EVSE. I had taken a short drive earlier that day and the first spike is charging me back to 80%. At 8:42 pm I hit the charge to 100% button and at 10:34 pm the truck started to slow down the charge. I'm estimating the 98.5% based on the time, an average of 11 kW, and about 10% loss. Regardless, it spent over 2 hours squeezing the last few electrons into the battery.

I've seen a near exact profile with an ER battery on a 80 amp EVSE [FCSP]

 

[EdRudy]

As @Maquis says above you are thinking of DC. You start to lose time when the truck is requesting less than the equipment can supply. That happens a lot sooner when there is 100 kW or more available on DC. The curve below shows my last 100% charge on an SR battery using a 48A (11.5 kW) EVSE. I had taken a short drive earlier that day and the first spike is charging me back to 80%. At 8:42 pm I hit the charge to 100% button and at 10:34 pm the truck started to slow down the charge. I'm estimating the 98.5% based on the time, an average of 11 kW, and about 10% loss. Regardless, it spent over 2 hours squeezing the last few electrons into the battery.

Thanks for the lesson!

 

[mr.Magoo]

Maybe someone finds this interesting, it's my "black box" data for the past 7-8 months.
(I don't have any data prior to that as I wiped my database due to a change in naming convention / structure of the same)

As you can see - according to the truck - the battery SoH is still 100% after 15 months and the module variation is pretty consistent over this whole time.

I do not follow "ABC" simply because I don't have that option, instead I charge when I get to 30-40% SoC and charge back up to 80%.
(I chose battery deg over dings from acorns and falling branches as my charger is outside, detached garage in a non forever home, cost prohibitive to trench and install charger in garage, power company wouldn't let me do a separate meter on the garage)

 

[sdingeldein]

Thanks to everyone who has commented to my original question. Special thanks to MickeyAO for his expertise.

 

[John Becker]

I've had my Lariat SR since 12/4/2023. Originally, I charged it every few days to 60 percent at 40 Amps.
After learning from this forum, I've changed my routine to charging to 60 percent daily at 16 Amps.
I don't know to what extent, if any, my charging routine maximizes SOH, but there's no inconvenience and I don't see any downside.
That said, if my travel schedule were to change, I'd change my charging routine to maximize my convenience. (Let the truck work for me rather than me work for the truck.) But I'm not going to abuse the battery if I don't have to.
And one more thing: Someday in the future, something like a "CarFax" report might include SOH and will help with resale value. (I'll more likely just give the truck to one of my kids.)

 

[CRAIGC540]

Rules of thumb

- It is best to keep battery between 30% and 80%-90%.

- Every time you charge a cell it loses a little life. Charging needlessly is something to be avoided.

- Conditioning battery for a brief period is better than running or charging it cold. If the battery is warm then preconditioning does nothing.

- DCFC is harder on battery than L2 charging at home.

Work within those rules and apply them to how you need to use the truck.

As an example... I have an ER with a daily short commute and always park in the garage which is kept above 10 degrees C. As such, I DO NOT charge every night because it would put needless wear on the battery with no benefits. I generally use the truck all week then charge it from around 35% back up to 85% on the weekend. I charge to 100% whenever going on a longer trip, as well as once every few weeks, whichever comes first.

If you don't have a garage then this doesn't apply. If you have a longer commute this doesn't apply. Etc. Use your head and work in those rules of thumb, don't try to take someone else's situation and clone it as everyone is different.

This is my exact MOA and seems best for the battery in this case.

 

[MickeyAO]

Charging from 80 to 90% 5 times vs from 40 to 90% once is basically the same thing.

ABC - always be charging
Keep plugged in in cold weather as the manual tells you.

No, it is not the same. I see this in the data from actually testing cells, and now I'm testing the SK 805A (if that seems familiar, it is the cell in your truck).

I've posted plenty of data on how to make your cells live virtually forever, and why I don't follow my own advice in some situations.

 

[OMO7]

No, it is not the same. I see this in the data from actually testing cells, and now I'm testing the SK 805A (if that seems familiar, it is the cell in your truck).

I've posted plenty of data on how to make your cells live virtually forever, and why I don't follow my own advice in some situations.

I've read through a bunch of your posts and I was kind of curious about a couple things if you don't mind.

You've stated closest to 50% is obviously ideal. I charge mine to 80%, and by the end of the day it'll be around 50%. Would it be better to charge as soon as I get home, or to leave it at 50% until for example 12AM and have it be fully charged by 6AM? I imagine the difference is negligible, but at this point I've just become curious.

Secondly you've said small charges are better than deep charges. Seeing as you can schedule charging schedules from the truck, would charging for an hour then stopping for an hour etc have any benefits over the long terms to battery health?

 

[Helium]

If you need 90%, charge to 90%. In the end, your warranty will cover the battery for 70% of the original capacity for 100,000 miles. You only need to worry if you have seen actual data or that 70% of original capacity will not do in 10 years.

Just some real world experience here. I've had my 2022 ER Lightning for 23 months at this point and I've crossed 101,000 miles. CarScan says I still have 97.5% of capacity left. For better than 95% of the time I've owned the vehicle I have charged it to 90% after every use. As you might imagine, this can mean that I have charged back to 90% SOC twice a day.

In other posts, I have stated that I recently switched to a lower SOC limit. This only lasted a few weeks because I came home below 10% to often in those weeks instead of it being an exception. In addition to avoiding going below 10% (and even 20% if I can help it), I also avoid going up to 100% unless I need it. Though I feel like I'm whipping a puppy when I do.

 

[Helium]

20%. 30% is better, but do what you need to do for your standard routine. Don't take it down to 0% on a routine basis.

Our testing shows that a 90% delta (95% SOC to 5% SOC) has the most degradation at normal temperatures. We have what is called Test 3 (25C, max charge current, max discharge current, 90% delta) usually shows the sharpest decline with and occasional Test 8 (55C, max charge, middle discharge, 60% delta) being the first to fail testing. This is out of a 9 test L2 matrix which tests 3 temperatures, 3 deltas, 3 charge currents, and 3 discharge currents. Looking at the graphs, it is very easy to see what is the dominant and secondary factors in aging for a particular cell.

My chest is all puffed up and my head has gotten to big to get through doors now. After reading around and trying to build a gestalt of the conflicting (or lacking) information on best long term charging policy to get 300,000 miles out of the truck, I guess I got it close to right unless their is something special about the SK 805A batteries that would alter the settings.

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