ProPower and the GOM

[Ventorum94]

This weekend tropical storm Ophelia came through North Carolina. On Friday night I went ahead and plugged the truck into my transfer switch in case we lost power. We never did lose power but it did flicker a couple of times just before bedtime so I went ahead and switched over instead of having to get up in the middle of the night to switch. I was plugged into the EVSE and had finished charging back to my normal 80% before I switched. I noticed a couple of interesting things.

First, when I switched on ProPower the truck starting charging at full power for a few minutes. Then it seemed to drop down and pull just about enough from the charger to run the ProPower. When I checked my charge in the morning I was still at 80% so it did not use any battery to keep the ProPower running. It seems that if you supply power to the charger and use the power from the ProPower you basically turn the truck into a very large UPS.

The other thing I noticed is that using ProPower affected the GOM. Usually at 80% my GOM shows about 180 miles (SR battery) but after running ProPower all night it was only showing 158 miles. The software really shouldn't use any zero mile trips to calculate the GOM numbers. I've got a road trip next weekend and this is going to make my estimates even less accurate. If @Ford Motor Company would give us a generator mode in the software it could prevent this and improve the accuracy of the GOM.

The screenshot shows the power supplied to the truck. I only drove a couple of miles on Friday so the initial charge on the left was only a few minutes. When it turns on again is when I was getting the truck started and making the switch. After the switch (the vertical line) the power drops and starts to mirror what the house was using.

You ask a question that raises an even more fundamental question: why have a GOM at all? This universal obsession with GOM accuracy is so unnecessary. The best it can do is predict future consumption based on recent past consumption (whether or not to include things like recent towing or ProPower use, is only one question that cannot be answered to every driver’s satisfaction…) Better than a GOM is a human brain: monitor displayed SOC, and calculate the range yourself while driving.
Example: if you have an ER pack, take displayed SOC and multiply by 3, and there’s your range! (add 10% if you’re driving under 50mph, subtract 10% if you’re driving over 70mph- subtract 50% if towing large trailer). Monitor displayed SOC, and update your brain-GOM range as you drive.
If you have an SR pack, multiply displayed SOC by 2, add 10% for a trip under 50mph, or subtract 10% for a trip over 70mph, subtract 50% if towing large trailer (or tailor your own towing correction based upon experience with your trailer). Monitor displayed SOC, and update your brain-GOM range as you drive.
Your brain-enabled GOM will be accurate enough never to leave you stranded, and you won’t have to wonder. Try it and see if it doesn’t end GOM anxiety altogether.

 

[carys98]

I wrote this in another thread, but it applies here:

From nearly six years of driving a Focus Electric, it appears that the GOM works by combining current conditions with recent history, with a heavier weighting on the most recent events. In other words, the last mile you drove has more significance than possibly the 10 miles before that, which is possibly more significant than the 100 before that, give or take.

In the end, the GOM is in the same group with weather forecasts.

For the Lightning, "recent history" likely included Pro Power use in addition to actual driving.

Exactly. A lot of other commenters seem to think I’m obsessed with the GOM. I’ve always treated it as a secondary data point that has limited usefulness. My ICE F150 also had one and it would give wildly different estimates when I filled up depending on whether my recent driving was my daily commute or if I had been on a road trip. I’m really just pointing out a flaw in the model with the hope that @Ford Motor Company will improve the model in the future.

 

[carys98]

Have you driven the truck after the PPOB testing?
Curious to see that the range estimate will revive to the 180 mile guesstimate in the first 5-10 miles of your trip.

EDIT: Spoke too soon. I did drive a couple of miles yesterday and I just assumed that wasn’t enough. I just checked FordPass and I’m now at 80% and showing 173 miles so it’s recovering quickly.

Not yet. I’m taking a road trip on Friday so we’ll see how quickly the bad data works its way out of the model.

 

[Calvin H-C]

My ICE F150 also had one and it would give wildly different estimates when I filled up depending on whether my recent driving was my daily commute or if I had been on a road trip. I’m really just pointing out a flaw in the model with the hope that @Ford Motor Company will improve the model in the future.

I hear ya! It's not like the GOM is a new thing with EVs, I've been using it for about 20 years in a few ICE vehicles before getting my FFE. It gave a reasonable, yet far from perfect idea if what you could expect. Plus, it wasn't much different from old gas gauges that would show the needle above the "full" Mark for about 50 miles of driving after filling up before it got down to "full", then seemed to drop a quarter of a tank each time you blinked.

Come to think of it, I wonder what my GOM would show if I backed out my FFE from the garage and put it away again a few dozen times... Putting the car away, a 24' drive, seems to consume about 1300 Wh/km, where typical operation in nice weather consumes about 150-190.

I usually provide the mileage equivalent, but it's the comparison that's important here. Just multiply by 1.6 for Wh/mi.

If I recall correctly, my wife's SR Lightning typically uses about 250-280 Wh/km, but displays it as 25.0-28.0 kWh/100 km, which is more like ICE vehicles where fuel consumption is in litres/100 km.

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