Battery Degradation Calculations

[1Jetpilot]

Tell me what you come up with:
My trip in 25 degrees 1.8 miles/kHw, all interstate at speed limits (55, 65, 40 mph)


Started with 312 DTE (100% SOC), Physical miles driven = 116 miles, I show 122 miles DTE at the end of the day

Tell me what % battery degradation you came up with and briefly how you calculated it

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[TaxmanHog]

Lost potential due to cold and driving mix was 24% off ideal

(((122+116)/131)/2.4)-1) = 24%

* assumptions 100% SOC and 131 KWH pack

 

[RickLightning]

Tell me what you come up with:
My trip in 25 degrees 1.8 miles/kHw, all interstate at speed limits (55, 65, 40 mph)


Started with 312 DTE, Physical miles driven = 116 miles, I show 122 miles DTE at the end of the day

Tell me what % battery degradation you came up with and briefly how you calculated it

I come up with zero. I see none. That's not battery degradation.

I see a GOM going from the default number to adjusting to current conditions. Didn't we already have this conversation? https://www.f150lightningforum.com/...fordpass-app-adjust-for-it.18019/#post-362190

My Lightning HVB shows 99.5%, so I have 0.5% over 8 months.

 

[TaxmanHog]

Winter electrons

 

[1Jetpilot]

I failed to enter a destination on the Ford Navigation. I strictly use Apple Car Play. Would this have made a difference?

 

[TaxmanHog]

Two issues, the truck is overly optimistic when SOC is above 80% and not knowing where and how you will drive it will not affect the present prediction, having a destination in Ford Nav will result in a predicted remaining range {DTE} that's more accurate, but subject to variation.

That's why I use Ford Navigation on longer winter trips, I watch the projection and see how it varies according to how I drive, be it faster/slower or more/less Eheat.

 

[djwildstar]

Tell me what you come up with: My trip in 25 degrees 1.8 miles/kHw, all interstate at speed limits (55, 65, 40 mph). Started with 312 DTE (100% SOC), Physical miles driven = 116 miles, I show 122 miles DTE at the end of the day. Tell me what % battery degradation you came up with and briefly how you calculated it.

Insufficient data.

I can say that the possible inaccuracies of the data you've provided are larger than any likely battery degradation. There is a 3.56 kWh possible variation in the amount of energy used by your trip. This is +/- 2.56% of your battery capacity.

Remember that the battery stores kWh, not miles, so we cannot conclude anything about the battery based on distance-to-empty figures other than that the guess-o-meter is subject to unexpected variation in projected range because we don't know the algorithm it uses to compute distance-to-empty values.

Here's what we can say:

• Trip start is 100% SoC. You want to compute battery degradation, so we must assume that the battery contains an unknown number of kWh at trip start; the objective is to estimate this number.
• You drive 116 miles at an average reported consumption of 1.8 miles/kWh.
  • The truck's user interface drops fractions, so actual efficency is between 1.800 miles/kWh and 1.899 miles/kWh.
  • Energy consumption for the drive is therefore between 61.08 kWh and 64.44 kWh.
• You arrive at an unreported state of charge, therefore we cannot estimate the number of kWh in the battery at the end of the trip. An end-of-trip SoC value would let us estimate the remaining kWh in the battery; this plus the kWh consumed during the trip would let us estimate kWh at 100% SoC.
• You do not report the number of kWh used to recharge the truck to a specific state of charge following the trip.
  • Ideally, SoC at the end of the trip and the number of kWh needed to recharge the truck back to 100% following the trip would give us a more-precise value for kWh consumed during the trip.
  • Charging data showing SoC at the start and end of the charge session, plus number of kWn charged could allow us to compute kWh per percent SoC; this in turn would let us estimate kWh stored at 100% SoC.
• If we had estimated kWh at 100% SoC (which we don't, and have no way of computing from the data you've given), then we could estimate battery health using Ford's nominal specification of 131.0 kWh at 100% SoC. For example, if we estimated 130.3 kWh at 100% SoC, we could then compute battery health as 130.3 / 131.0 = 0.9947 = 99.47% state of health, or 0.53% degradation.

 

[1Jetpilot]

The only data I got was 119 miles added, 34.2 kWh energy added but that was only to 80%. DTE shows 238. Sorry but it is still inconclusive

 

[TaxmanHog]

Jerry......

Is your question about battery health ie "Degradation from brand new" or accuracy of the DTE calculation?

 

[RickLightning]

Insufficient data.

I can say that the possible inaccuracies of the data you've provided are larger than any likely battery degradation. There is a 3.56 kWh possible variation in the amount of energy used by your trip. This is +/- 2.56% of your battery capacity.

Remember that the battery stores kWh, not miles, so we cannot conclude anything about the battery based on distance-to-empty figures other than that the guess-o-meter is subject to unexpected variation in projected range because we don't know the algorithm it uses to compute distance-to-empty values.

Here's what we can say:

• Trip start is 100% SoC. You want to compute battery degradation, so we must assume that the battery contains an unknown number of kWh at trip start; the objective is to estimate this number.
• You drive 116 miles at an average reported consumption of 1.8 miles/kWh.
  • The truck's user interface drops fractions, so actual efficency is between 1.800 miles/kWh and 1.899 miles/kWh.
  • Energy consumption for the drive is therefore between 61.08 kWh and 64.44 kWh.
• You arrive at an unreported state of charge, therefore we cannot estimate the number of kWh in the battery at the end of the trip. An end-of-trip SoC value would let us estimate the remaining kWh in the battery; this plus the kWh consumed during the trip would let us estimate kWh at 100% SoC.
• You do not report the number of kWh used to recharge the truck to a specific state of charge following the trip.
  • Ideally, SoC at the end of the trip and the number of kWh needed to recharge the truck back to 100% following the trip would give us a more-precise value for kWh consumed during the trip.
  • Charging data showing SoC at the start and end of the charge session, plus number of kWn charged could allow us to compute kWh per percent SoC; this in turn would let us estimate kWh stored at 100% SoC.
• If we had estimated kWh at 100% SoC (which we don't, and have no way of computing from the data you've given), then we could estimate battery health using Ford's nominal specification of 131.0 kWh at 100% SoC. For example, if we estimated 130.3 kWh at 100% SoC, we could then compute battery health as 130.3 / 131.0 = 0.9947 = 99.47% state of health, or 0.53% degradation.

Except you can't, due to temperature. Need mid 70s to see the truest data. CarScanner shows SOH% also.

 

[RickLightning]

Jerry......

Is your question about battery health ie "Degradation from brand new" or accuracy of the DTE calculation?

Right. Because they are apples and steak, nothing to do with each other.

 

[1Jetpilot]

Jerry......

Is your question about battery health ie "Degradation from brand new" or accuracy of the DTE calculation?

Accuracy of DTE

 

[RickLightning]

Accuracy of DTE

Then stop using the word "degradation", which has nothing to do with your goal.

If you want a MORE ACCURATE DTE, you must set a destination in the navigation. It will then PREDICT your DTE based on many factors. If it misses on some (like fails to predict the rain storm with headwinds that cut your range), it will adjust, and you will say "hey, this isn't accurate". If you drive 85mph and it predicted you would drive the speed limit at 70, it will adjust and again you will say "hey, this isn't accurate".

It just PREDICTS.

YOU need to be familiar with your miles per kilowatt hour, and multiply that times your battery size, to feel comfortable that you will have adequate range. For example, if you get 1.8 miles per kilowatt hour on the highway in the summer, and now it's 20 degrees out, that number is near useless. Take at least 30% off it to PLAN, and use 1.3, and watch This Trip to see how you do.

 

[1Jetpilot]

From my original thread, I got 1.8 kWh and it was 25 degrees

 

[RickLightning]

From my original thread, I got 1.8 kWh and it was 25 degrees

1.8 x 131 = 236 miles.

116 + 122 = 238 miles.

Seems right on the money to what you are getting as it should be, it's simple math.

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