Thinking on completely draining the HV Battery Pack. Thoughts?

[andres1227]

Hi all,

Not sure about this yet but checking the other day on CarScanner I found out the the State of Health of the battery was set 98.5%. A few days later I had to make a long trip so I charged my truck all the way to 100% which at 99% it still provided like 10-ish additional kWh for the battery to get to 100%.

After this, I found out that the State of Health changed from the previous 98.5% to 99%.

Since then I’ve been thinking of letting the HV battery completely drain to have the system kind of reset.

Any thoughts? Has anyone done this for the same purpose? If so, what have you found?
TIA

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[Maquis]

This also would apply to the Lightning…
https://www.macheforum.com/site/threads/hv-battery-calibration-procedure.23815/

 

[garsh]

Any thoughts?

There are two things to consider:

1. What's best for the health of the battery
2. What's best for measuring the battery's state accurately

Lithium Ion batteries prefer to sit around 50%. Cycling them will cause some degradation. Leaving them to sit at high SOC (state of charge) will cause some degradation. Leaving them to sit at low SOC will cause some degradation. These degradation effects are very small, but they add up over the lifetime of the battery.

The Battery Management System is what tries to report on the health of the battery. They will be more accurate as the battery cycles through a wider range of SOC. Most BMS will show a conservatively lower state of health/charge when it hasn't seen enough SOC range to be accurate, so as not to accidentally leave you stranded when you thought you had more range remaining.

If you're actually worried about the health of the battery, just leave it be. If you want a more accurate measurement of battery health, "calibration" can be used now and then to provide that.

 

[andres1227]

This also would apply to the Lightning…
https://www.macheforum.com/site/threads/hv-battery-calibration-procedure.23815/

Thanks for the info! I will follow those instructions!

 

[andres1227]

There are two things to consider:

1. What's best for the health of the battery
2. What's best for measuring the battery's state accurately

Lithium Ion batteries prefer to sit around 50%. Cycling them will cause some degradation. Leaving them to sit at high SOC (state of charge) will cause some degradation. Leaving them to sit at low SOC will cause some degradation. These degradation effects are very small, but they add up over the lifetime of the battery.

The Battery Management System is what tries to report on the health of the battery. They will be more accurate as the battery cycles through a wider range of SOC. Most BMS will show a conservatively lower state of health/charge when it hasn't seen enough SOC range to be accurate, so as not to accidentally leave you stranded when you thought you had more range remaining.

If you're actually worried about the health of the battery, just leave it be. If you want a more accurate measurement of battery health, "calibration" can be used now and then to provide that.

Thanks for the recommendation. I believe the correct word for what I want is to calibrate it so it can work at its best performance.

 

[Timeless Epoch]

Looks like your cells were slightly out of balance and the charge to 100% fixed that. As expected.

I have never read anything authoritative showing an advantage of an occasional deep discharge. In my opinion it is just forum lore with nothing behind it.

There are two things that affect SOC accuracy. Accurate SOH information and balancing. SOH would be measured by power in vs voltage rise, voltage sag under load, and internal resistance. None of those require a deep discharge to figure out and balancing is fixed with a 100% charge.

In my opinion, charge to 100% a few times per year and enjoy your truck.

 

[garsh]

I believe the correct word for what I want is to calibrate it so it can work at its best performance.

Calibration doesn't make the battery perform any better. It just allows the BMS to have a better understanding of the battery's state.

 

[Heliian]

The first line of that Mach e post:

"First, I'll mention there is no official procedure from Ford for battery calibration. However I think it helps to do this"

Do whatever you feel is necessary but there isnt any manufacturer data to support the theory.

 

[RocketGhost]

Data that's been trickling in from owners as more time and miles are put on our trucks shows that the battery health is managed very well in these trucks. I'm convinced that measures specifically to prolong battery life beyond Ford's recommendation to charge to 90% for regular use and 100% if you need it are a waste of time.

 

[djwildstar]

[...] I’ve been thinking of letting the HV battery completely drain to have the system kind of reset. Any thoughts? Has anyone done this for the same purpose? If so, what have you found?

Two thoughts:

First, use Mach-Lee's NCM battery calibration procedure (linked above in this thread). In a nutshell, the procedure is to disable remote start and departure times, drive down to 5%, let it sit unplugged overnight, charge to 100%, let it sit plugged in for several hours, drive down to 10%, and then resume normal use (including normal charging routine, departure times, remote start, etc.).

Second, you don't want to go to 0%. Not only is actually hitting 0% unpredictable, but staying at 0% for any length of time is more-harmful to the battery than staying at 100%. Ford's battery warranty contains an exclusion for batteries that were stored at 0% for two weeks or more. So if something happens that prevents you from charging back up promptly, you could be in for expensive trouble.

 

[djwildstar]

Data that's been trickling in from owners as more time and miles are put on our trucks shows that the battery health is managed very well in these trucks. I'm convinced that measures specifically to prolong battery life beyond Ford's recommendation to charge to 90% for regular use and 100% if you need it are a waste of time.

I agree with you here.

I'm currently at just shy of 3 years and 45,000 miles. In the last ~1000 miles, my battery health dropped from 99.5% to 99.0%. This compares very favorably to the Tesla long-term studies, which show an expected battery health of 94%-96% for vehicles of similar age and mileage.

The only reason I can think of to "baby" a Lightning battery is if you intend to keep the truck well beyond 20 years and somewhere into the 300,000 to 500,000 mile territory. At those ages and mileages, a any percentage points of degradation saved in the first 250,000 miles will serve you well in the second 250,000.

 

[RickLightning]

Two thoughts:

First, use Mach-Lee's NCM battery calibration procedure (linked above in this thread). In a nutshell, the procedure is to disable remote start and departure times, drive down to 5%, let it sit unplugged overnight, charge to 100%, let it sit plugged in for several hours, drive down to 10%, and then resume normal use (including normal charging routine, departure times, remote start, etc.).

Second, you don't want to go to 0%. Not only is actually hitting 0% unpredictable, but staying at 0% for any length of time is more-harmful to the battery than staying at 100%. Ford's battery warranty contains an exclusion for batteries that were stored at 0% for two weeks or more. So if something happens that prevents you from charging back up promptly, you could be in for expensive trouble.

There are no remote start times...

Why would you restate the procedure, making edits, instead of just posting it exactly?

1. Charge the vehicle to your normal level (e.g. 90%).
2. Drive the vehicle (without charging) until the battery is down to 5% or less.
3. Park the vehicle and let the battery rest for at least 5 hours (preferably overnight)
4. Level 2 charge all the way to 100% in one session without interruption.
5. Leave the vehicle plugged in and let the battery rest for 3+ hours after 100% is reached.
6. (Optional) With a scan tool, read the kWh to empty and state of health parameters.
7. Drive without charging until battery is below 50% (10% recommended)
8. Charge the vehicle back up to your normal level.
9. Repeat if desired.

 

[andres1227]

Two thoughts:

First, use Mach-Lee's NCM battery calibration procedure (linked above in this thread). In a nutshell, the procedure is to disable remote start and departure times, drive down to 5%, let it sit unplugged overnight, charge to 100%, let it sit plugged in for several hours, drive down to 10%, and then resume normal use (including normal charging routine, departure times, remote start, etc.).

Second, you don't want to go to 0%. Not only is actually hitting 0% unpredictable, but staying at 0% for any length of time is more-harmful to the battery than staying at 100%. Ford's battery warranty contains an exclusion for batteries that were stored at 0% for two weeks or more. So if something happens that prevents you from charging back up promptly, you could be in for expensive trouble.

Very useful information!! Thanks for the heads up!

 

[bc1]

Guess I'm less worried about BMS calibration and more about battery longevity. The BMS with its percentages and estimated miles is never accurate anyway as it depends upon what happens on the next drive.

When I first bot it just over 3 months ago I drove it over 200 miles home starting at 100% and used a 120v charger for a while. First trip to nearby town to get to a big charger had me limping into town on the back roads at 35 mph at 1% then probably right at 0% sweating bullets on a busy street hoping it don't shut down as I pulled up to the charging station. My Extended battery with 131 kwh useable and 144 kwh actual still had its reserve capacity in it. Looking back at the charge ticket, it took 135.144 KWH in 2h 49min to get back to 100%. So apparently I ran it down the very first time.

Now with winter here, I plug it and charge it to 100% whether I drove 30 miles or 60 or 150. I'm afraid to go to 80 or 90% because I may wakeup and need to drive somewhere and the wife or I don't want to have to worry about being stuck out in the Kansas boondocks. Don't need that extra anxiety at our old age. So I'll just deal with it for now and maybe in the spring I can not have to plug in every night.

 

[Zprime29]

I did something very close to this a while ago: https://www.f150lightningforum.com/forum/threads/100-range-test-follow-along.25107/

Initial charge to 100% showed 126.9kWh. After driving all week down to 14% or so and charging back in one session, I showed 128.3kWh. The past winter I had 126.5kWh at 100%. At 3.5 years and 53k miles I'm happy with that. If I assume 80% capacity after 10 years (I don't think it will be that low) I'd still have 280 miles of range at my efficiency (local driving). I can live with that.

I expect this will be the first vehicle I hit the 200k mark. 150k is the most I've driven on a single car prior to this. That's usually about the point I look to upgrade. Since I now have a collector's car, I'm keeping it!

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