Running the Battery to 0%

[Helium]

So based on your data are you saying it is recommended to be in the 20% to 70% range? I only went below 20 once to 15% and only went to 100% once for a trip. Any concerns there or just minimize those as much as possible? Thanks

Chart here lays this out very nicely:
https://www.f150lightningforum.com/...epth-of-charge-graph-for-nmc-batteries.19465/

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[Helium]

I had a similar experience, and while at first I thought I was 'out' of all power, it actually wanted me to put it in PARK, then back into gear, to move forward, even slowly... give it a try next time.

When I ran out of power (just so happen to crossing opposing traffic on a service road) I shut the truck off for 30 seconds (of course at this point I was in park), restarted and limped my way to the charger.

 

[invertedspear]

100% display is HVB SOC 97% and it’s around 127kWh.

How did you figure these numbers? The true size of the battery pack is ~143 kWh, the system only let's you charge it up to 131 kWh. at 75F (the ideal temp for this battery) a 100% charge as displayed on the dash should be 131 kWh, if you have some way of reading that it's less than that, you should be making a warranty claim as you have dead cells.

I just wish they would match.

For better or worse, this is Ford protecting us from ourselves. All the research says fully charging you battery is bad for the overall long-term health of the battery. If they want all their batteries to meet the federally mandated warranty period of 8 years or 100,000 miles, they have to prevent us from charging it to a true 100% or else many people would kill that battery in just a few years.

 

[Dukhudo]

I'm getting my information from Car Scanner. If you look around the forum, some members have posted the same or similar information to mine regarding the HVB SOC Display vs HVB SOC.

 

[Yellow Buddy]

How did you figure these numbers? The true size of the battery pack is ~143 kWh, the system only let's you charge it up to 131 kWh. at 75F (the ideal temp for this battery) a 100% charge as displayed on the dash should be 131 kWh, if you have some way of reading that it's less than that, you should be making a warranty claim as you have dead cells.


For better or worse, this is Ford protecting us from ourselves. All the research says fully charging you battery is bad for the overall long-term health of the battery. If they want all their batteries to meet the federally mandated warranty period of 8 years or 100,000 miles, they have to prevent us from charging it to a true 100% or else many people would kill that battery in just a few years.

Use an OBD with Carscanner. It will tell you the actual remaining capacity as well. My battery at 100% only has 123kWh vs 131 now.

 

[Adventureboy]

No adapter with my early 2023 delivered Dec. 2022.

 

[invertedspear]

I'm getting my information from Car Scanner. If you look around the forum, some members have posted the same or similar information to mine regarding the HVB SOC Display vs HVB SOC.

Can you check your SOH as well? If your SOH is still like 99% I think there's something misrepresented by Ford here. All their docs say 131 usable kWh and if that's not what's available with a neat 100%SOH, then there's a false claim and possible lawsuit here.

 

[SpaceEVDriver]

This chart supports your assertion. The black\blue\red dots across the top are full cycle "capacity checks" taken time to time during 2.5 years of testing.

Note also that this is using a C/3 charging/discharging rate. For a 130 kWh battery, C/3 is a charge/discharge rate of 43 kW. Even the 80A Charge Station Pro only provides 20 kW, which is only C/6.5. (Dis)Charging at a lower rate gives an even better lifetime.

For discharging, C/3 is equivalent to driving at highway speeds (70-85 mph) for about 2.5-3.5 hours.

 

[Yellow Buddy]

Can you check your SOH as well? If your SOH is still like 99% I think there's something misrepresented by Ford here. All their docs say 131 usable kWh and if that's not what's available with a neat 100%SOH, then there's a false claim and possible lawsuit here.

Yes it gives SOH.

The car scanner app gives you plenty of information to derive it. While the car has 131kWh usable new, it doesn’t necessarily stay there.

Attaching a video of some of the sensors it’s reading:


In it, you’ll see the following:
HVB SOC: 55.96% (0:23 in video)
Displayed HVB SOC is 59% (0:46 in video)
HVB Energy to Empty is 51.61kWh (0:46 in video)

The discrepancy is to account for exactly what you’re saying - the buffer.
If we calculate 51.61kWh/55.96% = 92.2kWh (actual)
Comparatively 51.61/59% = 87kWh displayed (usable)

Since the Pro SR has 98kWh usable new, this indicates this particular truck has approximately 11% of degradation over 21 months.

The SoH sensor on car scanner is not accurate (In my opinion) I have not seen any truck read anything other than 100% for SoH regardless of where the battery degradation is. It may be considering health as something else (for example bad modules) every cell could very well be “healthy” but aged with reduced capacity. *This last paragraph is speculation.

I will be connecting the OBD and Carscanner to a brand new truck tomorrow and will be able to report back on what the values are for comparison.

 

[Helium]

Note also that this is using a C/3 charging/discharging rate. For a 130 kWh battery, C/3 is a charge/discharge rate of 43 kW. Even the 80A Charge Station Pro only provides 20 kW, which is only C/6.5. (Dis)Charging at a lower rate gives an even better lifetime.

For discharging, C/3 is equivalent to driving at highway speeds (70-85 mph) for about 2.5-3.5 hours.

I didn't think about what "action" that would represent in the real world, I was only thinking about charge cycles available to be used. Not that it would take plenty of high speed driving to use that much power at that rate. Thanks.

The more I learn about that battery, the less I'm worried about my usage pattern and its longevity. Barring something in the battery out right failing, I think the rest of the truck will be dead by the time the battery is ready to be recycled.

 

[Newton]

The discrepancy is to account for exactly what you’re saying - the buffer.
If we calculate 51.61kWh/55.96% = 92.2kWh (actual)
Comparatively 51.61/59% = 87kWh displayed (usable)

That does not appear to be the case from my testing. The ratio between the SOC (internal) and SODD (displayed state of charge) is not fixed, and in fact which one is greater depends on the state of charge (apparently.)

I should probably do a standalone post on this, but think on these three photos for a bit. This was during our recent 1500 mile trip down the Oregon and Washington coasts. We were at the Oregon Gardens in Silver Falls and I happened to take three measurements while we were getting ready to go. There was a very short drive after 6:23AM as I drove the truck from the charger site to closer to the hotel room.

You can see that immediately after I unplugged the truck the internal state of charge was 95.85% while the display showed 100%. Two minutes later it was 95.73% vs 100%. Twelve minutes after unplugging it was 95.17% vs 100%. The truck was on only very briefly during this intervals (the doors were open but the power was off.) During the period the stated amount of energy in the battery dropped by almost 2kW! I did not drive four miles in that time.

What I believe is going on here is that the total kWh is determined by the internal state of charge. The displayed SOC is based on columb counting, while the internal state of charge is recalibrated to the resting voltage of the battery when the truck gets a chance to. As the truck rests after charging the battery voltage will drop.

This is a long-winded way to say that there is not a simple relationship between the state of charge that the truck shows the user and what it internally thinks the state of charge is. I believe that the range is controlled by the internal state of charge, but charging is based on the external less accurate one. So when you charge to 80% you are never actually charging to 80%.

More evidence for the complexity (I have lots of data). When I left I charged to 100%, displayed SOC was 100% and internal was 94. At a later stop I took it down to 27% according to Ford Pass, by my numbers displayed SOC was 27.5 and the internal was 28.4 - a reversal.

Its complicated.

 

[SpaceEVDriver]

That does not appear to be the case from my testing. The ratio between the SOC (internal) and SODD (displayed state of charge) is not fixed, and in fact which one is greater depends on the state of charge (apparently.)
.
.
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More evidence for the complexity (I have lots of data). When I left I charged to 100%, displayed SOC was 100% and internal was 94. At a later stop I took it down to 27% according to Ford Pass, by my numbers displayed SOC was 27.5 and the internal was 28.4 - a reversal.

Its complicated.

There are two things going on here...

First, there's a lower as well as an upper buffer. So when the displayed SoC (SoCD) is at 100%, the "real" SoC (SoCR) is less than 100%, and when the SoCD is at 0%, the SoCR is closer to about 5-10%. These differences depend on temperature, load, and other factors. There's a point somewhere around 50% where the difference between the SoCR and SoCD is 0.

Second, when the truck is on and there's a load on the battery, it doesn't read the same state of charge as it would when the truck is off without a load. Shutting the truck off causes the SoCR to change after the battery is no longer under load. It usually takes a bit of time to settle.

Checking the difference between the displayed and "real" state of charge after leaving the truck off for a few hours (or at least a few tens of minutes) will give you a better reading.

 

[Yellow Buddy]

That does not appear to be the case from my testing. The ratio between the SOC (internal) and SODD (displayed state of charge) is not fixed, and in fact which one is greater depends on the state of charge (apparently.)

I should probably do a standalone post on this, but think on these three photos for a bit. This was during our recent 1500 mile trip down the Oregon and Washington coasts. We were at the Oregon Gardens in Silver Falls and I happened to take three measurements while we were getting ready to go. There was a very short drive after 6:23AM as I drove the truck from the charger site to closer to the hotel room.

You can see that immediately after I unplugged the truck the internal state of charge was 95.85% while the display showed 100%. Two minutes later it was 95.73% vs 100%. Twelve minutes after unplugging it was 95.17% vs 100%. The truck was on only very briefly during this intervals (the doors were open but the power was off.) During the period the stated amount of energy in the battery dropped by almost 2kW! I did not drive four miles in that time.

What I believe is going on here is that the total kWh is determined by the internal state of charge. The displayed SOC is based on columb counting, while the internal state of charge is recalibrated to the resting voltage of the battery when the truck gets a chance to. As the truck rests after charging the battery voltage will drop.

This is a long-winded way to say that there is not a simple relationship between the state of charge that the truck shows the user and what it internally thinks the state of charge is. I believe that the range is controlled by the internal state of charge, but charging is based on the external less accurate one. So when you charge to 80% you are never actually charging to 80%.

More evidence for the complexity (I have lots of data). When I left I charged to 100%, displayed SOC was 100% and internal was 94. At a later stop I took it down to 27% according to Ford Pass, by my numbers displayed SOC was 27.5 and the internal was 28.4 - a reversal.

Its complicated.

Exactly as @SpaceEVDriver mentioned.

I did plugged into a brand new truck today and found it quite interesting. SR, 2024 less than 100 miles on it and it did NOT have 98kWh usable according to CarScanner. It displayed 88kWh at 90% SoC Internal and 98% Displayed, that would suggest a 98kWh battery pack but only 90kWh usable.

Unfortunately I didn't take measurements of my 2022 Pro when it was new, but IF it was the same then the degradation on that truck over 30,000 miles is only approximately 3.5%.

IF it wasn't the same when it was new and it actually had 98kWh usable, then the new car for some reason comes with far less usable capacity.

All of this is using a tool that is aftermarket, an app that should be good but unknown. So while informative, it's still speculative. I'm assuming the sensors are accurate and it is reporting correctly through the tool and app.

 

[Helium]

I think I should take the time to pull the battery management software and other battery related software off the truck and spend a few weekends reverse engineering it. So much of this interpretation of the physical state of the battery is being done in software. I'd like to know why it took 15 miles at a steady 48mph for the battery to go from a displayed 100% to 99% but by the time I completed a 42 mile circuit, the displayed values matched up to a reasonable 3 m/kwh for that speed.

Anyway, this thread has been amazing if only to validate my questions about the behavior of the truck is caused by more than sparse data sampling.

I wonder how much @Ford Motor Company would be irritated if I posted a graph of what the software is doing at a range of charge levels and possibly a list of variables they are using in their calculations....

I could write an app that logged data from the vehicle, recorded every available variable (both actual and derived) the truck is using\recording, while also recording data from various external instruments to measure the environment the truck is operating in.

The next step after that would be instrumenting the truck itself, giving an independent but parallel set of data to compare to.

 

[Helium]

I could write an app that logged data from the vehicle, recorded every available variable (both actual and derived) the truck is using\recording, while also recording data from various external instruments to measure the environment the truck is operating in.

The next step after that would be instrumenting the truck itself, giving an independent but parallel set of data to compare to.

If I could get a group of volunteers to gather the data from their vehicles and give me the maintenance records for their vehicles. It should be fairly direct to apply some predictive failure analysis to the data with the added dimension of being able to see some components degrade in real time.

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