HV Battery Calibration Procedure

[darkastor]

I managed to get an OB2 tool so I wanted to experiment and see where my 2021 that I bought used was at with 25K miles on the clock. Car scanner was showing that my HVB SOH was 92.5% which checked out with the 2021 page at my batteries age.

I ended up starting at 22% as it was only showing 40 something miles and I didn’t have time to run it down a bit further

I let it sit all day and charge up to 100% (finished somewhere around 3 this morning) and this is what my data point was afterwards:

Now here’s the interesting point. While I was sitting there getting that information and looking at a couple things, it was actually still adding addition power to the battery and closing that 4% difference between the displayed % and actual battery %. I had to run to an appointment so I didn’t let it go for forever (I also only use a 16 amp unit). At my end it still displayed 100% for my vehicle display, but the battery SOC had increased to 96.1% and my power in battery ended around 84.3 kWh. I would guess if it continued to 100% for the battery SOC it would have ended at around 85 or 86 kWh in the battery. 85/88=0.9659 which is quite a bit better than the previous mentioned value.

Would it be worthwhile to have the vehicle condition the battery around the last hour of the test to fullsee the capacity it has? It was roughly 50 degrees here in Minnesota during this test and my vehicle charges in an insulated garage.

-G

Sponsored

 

[N1naz]

~ 8% differance, Just goes to show ya how far off they can be. Not going to go under 10% I don't trust it. Just did a 12% to 100% charge at 40amp rate. (yes I drove it after it finished thats why its showing these numbers, was at 99% for the display, never seen 100%)

HVB SOC vs HVB SOC Display

 

[Elar]

Today I reduced the car from 100% to 4,5% (6.22 kwh). Evening 20.30 and -3Celsius.
Should I put the car on the charger in the morning?

 

[Mach-Lee]

Today I reduced the car from 100% to 4,5% (6.22 kwh). Evening 20.30 and -3Celsius.
Should I put the car on the charger in the morning?

Yes, it needs to sit at 4.5% undisturbed for a number of hours before you do the uninterrupted charge to 100% next.

 

[Elar]

I did this calibration.
Data:
Start, OBD: HvbSoc 8.56%, HvbSocDisplay 4,5% , Energy 6.22 kwh
End, OBD: HvbSoc 95,91%, HvbSocDisplay 100% , Energy 79.07kwh

The amount of charge according to the Fordpass display: 85,1 kwh
The amount of charge according to the charger display 91,6 kwh (23:13 h)

I do not understand the difference in energy data
SOH: 95.5%

 

[Mach-Lee]

I did this calibration.
Data:
Start, OBD: HvbSoc 8.56%, HvbSocDisplay 4,5% , Energy 6.22 kwh
End, OBD: HvbSoc 95,91%, HvbSocDisplay 100% , Energy 79.07kwh

The amount of charge according to the Fordpass display: 85,1 kwh
The amount of charge according to the charger display 91,6 kwh (23:13 h)

I do not understand the difference in energy data
SOH: 95.5%

Good, so your state of health went from 86% to 95.5% after doing the calibration? I would repeat the calibration one more time since there was a large increase.

85.1 kWh /91.6 kWh = 93% charging efficiency which is typical.

The energy to empty parameter must be reporting low since the battery took in more kWh than it says is available. Could be low from the pack being cold too.

85.1 kWH added / 95.5% added = 89 kWh available at 100% - Battery is doing fine

 

[Trick.Mach-E]

So for our FE's 4 Year Anniversary I did the battery calibration for the first time at 49,917 miles. I ran the Mach-E GOM down to 0% and 0 miles but the SoC showed 4.46%... And while I did let the car sit overnight before charging about 2 hours after I put it in the garage I wanted to see if the SoC was any lower and it was higher... 2% on the GOM and 6.3% was the actual SoC.

It took the battery about 10:45 to fully charge to 100%... current stats...

Ford App - 87.1k Wh added
ChargePoint - 92.678 kWh added

Car Scanner...

HVB SoC - 96.61%
HVB Energy to Empty - 86.04 kWh
SoH - 93.5%

Thanks @Mach-Lee for the how-to!

 

[kens]

I plan to do this calibration soon, but have a question in the meantime. Is this below behavior unusual?

I've been DCFC for the first few weeks I've had the car, with a couple free slow chargers at restaurants thrown in, and have never successfully charged to 100%. The car will get up to about the low 90's and then the displayed SOC will suddenly jump to 100% ending the session, I've experienced this three times so far.

I've gotten Car Scanner and can see at lower SOC the display and app are nearly aligned, the higher the SOC they get more out of sync, then the sudden jump to the displayed SOC at the end.

As it sits now about half full they are close to agreement, tough 41kWh seems low for a 50% charge.

Sunday I attempted to fully charge, but this is where it ended after a sudden jump, by the time I drove 2 miles home the displayed SOC was 88%.

Car Scanner reports health to be 96.5%.

Is this something you've seen before? I'll have a weeks access to a home charger starting next week, and plan to do a calibration then.

 

[Mach-Lee]

I plan to do this calibration soon, but have a question in the meantime. Is this below behavior unusual?

I've been DCFC for the first few weeks I've had the car, with a couple free slow chargers at restaurants thrown in, and have never successfully charged to 100%. The car will get up to about the low 90's and then the displayed SOC will suddenly jump to 100% ending the session, I've experienced this three times so far.

I've gotten Car Scanner and can see at lower SOC the display and app are nearly aligned, the higher the SOC they get more out of sync, then the sudden jump to the displayed SOC at the end.

As it sits now about half full they are close to agreement, tough 41kWh seems low for a 50% charge.

Sunday I attempted to fully charge, but this is where it ended after a sudden jump, by the time I drove 2 miles home the displayed SOC was 88%.

Car Scanner reports health to be 96.5%.

Is this something you've seen before? I'll have a weeks access to a home charger starting next week, and plan to do a calibration then.

What you are showing me would seem to indicate that your pack is out of balance. So I did some digging, not sure how much you know, but it looks like your vehicle was affected by the 23B12 recall, and just had a cell module replaced earlier this month? When you replace a cell module, it has to be balanced to match the rest of the pack. However it appears they may not have done the balancing correctly, it appears there was over two weeks from the time they read the pack voltages to when they installed the new module (was it sitting all that time?), and when they were doing that the battery temp was very cold (affects accuracy). They are supposed to have both the pack and the new module warmed up to similar temps, and read the pack voltages for balancing immediately before the install.

The pack being out of balance will correct itself within 22 days. To help, try to charge consistently to the same SoC each night (such as 90%) and leave it on charge as much as possible. You will not be able to charge to 100% (and have it stick) until the pack is balanced enough. Hence your plans to do a calibration may need to be postponed.

 

[kens]

What you are showing me would seem to indicate that your pack is out of balance. So I did some digging, not sure how much you know, but it looks like your vehicle was affected by the 23B12 recall, and just had a cell module replaced earlier this month? When you replace a cell module, it has to be balanced to match the rest of the pack. However it appears they may not have done the balancing correctly, it appears there was over two weeks from the time they read the pack voltages to when they installed the new module (was it sitting all that time?), and when they were doing that the battery temp was very cold (affects accuracy). They are supposed to have both the pack and the new module warmed up to similar temps, and read the pack voltages for balancing immediately before the install.

The pack being out of balance will correct itself within 22 days. To help, try to charge consistently to the same SoC each night (such as 90%) and leave it on charge as much as possible. You will not be able to charge to 100% (and have it stick) until the pack is balanced enough. Hence your plans to do a calibration may need to be postponed.

I just bought it and had to wait for them to get the recall finished to pick it up, it was on a lift with the pack out the day I signed, as far as I know it didn't move from there during the wait. I knew they were replacing the module, though I thought they said it had two to replace, and I was delayed picking it up when they said the wrong modules were delivered.

From my Prius days I would have expected a lengthy balancing procedure with a module swap, but considering how quickly they finished from when the right parts arrived I suspected that didn't happen.

I don't have home charging yet, so I'm relying on DCFC, but don't have a problem stopping each day to top up if you think it'll help, I just won't be able to let it soak up the slow home charger.

When you say it will correct within 22 days, is that from today, or when they put it back together on 2/6?

 

[Mach-Lee]

I just bought it and had to wait for them to get the recall finished to pick it up, it was on a lift with the pack out the day I signed, as far as I know it didn't move from there during the wait. I knew they were replacing the module, though I thought they said it had two to replace, and I was delayed picking it up when they said the wrong modules were delivered.

From my Prius days I would have expected a lengthy balancing procedure with a module swap, but considering how quickly they finished from when the right parts arrived I suspected that didn't happen.

I don't have home charging yet, so I'm relying on DCFC, but don't have a problem stopping each day to top up if you think it'll help, I just won't be able to let it soak up the slow home charger.

When you say it will correct within 22 days, is that from today, or when they put it back together on 2/6?

Yes they replace the cell modules in pairs (they share one cooling plate). They use a cell balancing charger that should finish the module balance in 14 hours or less. If you got it back and have been driving it since the 6th, well it's been 20 days. So if it's still not hitting 100% in a couple days, it means you had an extreme imbalance to begin with. You can either wait it out longer, or decide to bring it back and tell them they need to rebalance it properly (which requires dropping the pack and removing it again). Based on what you report, your imbalance might be as high as 10% still.

Again, if you aren't charging up to 80%+ each night on L2, the car sits at lower SoC values, the car is parked outside in the cold with no battery heating, or the car sits unused for many days at a time, it makes it much harder to accurately balance the cells.

 

[kens]

Again, if you aren't charging up to 80%+ each night on L2, the car sits at lower SoC values, the car is parked outside in the cold with no battery heating, or the car sits unused for many days at a time, it makes it much harder to accurately balance the cells.

I don't mind waiting a bit if it will self correct, better than leaving it with them for what would probably turn into weeks. The car is fine for me day to day. I'm often charging to over 80%, and can do that daily if needed, but don't have level 2 at the moment. It's been cold here and I've been charging frequently as it is, most days I park at a higher SOC than today, and don't tend to go multiple days without driving.

I will have access to level two starting next week for about a week and will take full advantage of it.

 

[Mach-Lee]

I don't mind waiting a bit if it will self correct, better than leaving it with them for what would probably turn into weeks. The car is fine for me day to day. I'm often charging to over 80%, and can do that daily if needed, but don't have level 2 at the moment. It's been cold here and I've been charging frequently as it is, most days I park at a higher SOC than today, and don't tend to go multiple days without driving.

I will have access to level two starting next week for about a week and will take full advantage of it.

So I was thinking about this more, and best I can tell the balancing current of the BECM is probably about 100 milliamps per cell. A cell group is 284 Ah, so if you are off by 10% now, it will take another 12 days of continuous balancing to correct (March 10th). Try to charge to 90% each day if you have time (100% nightly on Level 2 once you have that), and try to get the battery temp above +10ºC while doing so. If temps are low, shut off HVAC while charging until it warms up.

 

[JimmyMachE]

I plan to do this calibration soon, but have a question in the meantime. Is this below behavior unusual?

I've been DCFC for the first few weeks I've had the car, with a couple free slow chargers at restaurants thrown in, and have never successfully charged to 100%. The car will get up to about the low 90's and then the displayed SOC will suddenly jump to 100% ending the session, I've experienced this three times so far.

I've gotten Car Scanner and can see at lower SOC the display and app are nearly aligned, the higher the SOC they get more out of sync, then the sudden jump to the displayed SOC at the end.

As it sits now about half full they are close to agreement, tough 41kWh seems low for a 50% charge.

Sunday I attempted to fully charge, but this is where it ended after a sudden jump, by the time I drove 2 miles home the displayed SOC was 88%.

Car Scanner reports health to be 96.5%.

Is this something you've seen before? I'll have a weeks access to a home charger starting next week, and plan to do a calibration then.

I think you should definitely watch two other sensors in Car Scanner:
HVB SOC module variation %
HVB voltage module variation V

https://www.macheforum.com/site/threads/battery-health-at-143-000-miles.39942/page-2#post-866068

 

[kens]

I think you should definitely watch two other sensors in Car Scanner:
HVB SOC module variation %
HVB voltage module variation V

https://www.macheforum.com/site/threads/battery-health-at-143-000-miles.39942/page-2#post-866068

Pretty high variation for now.

Sponsored