New sensation: :NOTHING from the 'gas' pedal : / out of juice!

[lightspeed]

I hate to break it to you but going backwards probably has nothing to do with it.

If you watch other people who have run their EVs down to zero, there is often a period where after reaching no power, you can stop for a few minutes and then get a little power, then stop again, then get a little power, etc..

The system that is preventing you from depleting the battery to its real zero (to protect it) reads the voltage of the battery. When you stop for a few minutes, that voltage can bounce back a little because of the nature of batteries and the battery protection system allows a little more power. Eventually, the voltage will fall below the protection threshold permanently.

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[trev5150]

 

[hturnerfamily]

I would bet that this is, at least in part, a software thing. My edumaguess is that Ford put code in to limit the power in forward when the battery gets low, but didn't bother to make the same code apply in reverse.

one of my first thoughts... after wiping the sweat from my brow : )

 

[hturnerfamily]

What was the SoC when you left the chargers at Ft. Payne?

can't remember exactly now, but the guessometer had 10 more miles than we needed... although I didn't look at the SOC so much... when we 'arrived' at Young Harris - the SOC was 1%, and the 'miles' were still showing 2.

 

[hturnerfamily]

Did you GOM read zero miles before you got to your destination? Wondering if it is like ICE vehicles where you continue on zero for some time. Did you lose accessory power at any time or is that all run on the 12V? Do you think you gained any regen distance on your roll down the hill?

nope, never read 0, which is why I didn't hesitate to try to break the last hill... but apparently getting exactly to '0' is not in Ford's planning...

 

[hturnerfamily]

hey! that was ME! except it was 11pm, dark thirty, and no one else around! Crazy...






stop spying on me!

 

[hturnerfamily]

Hope they don’t “fix” it then. I suspect they did it deliberately to get you out of precarious situations, allowing you to get into the secret squirrel ~2% reserve.

with a 107kwh battery pack, and 98 'usable' power, I suspected that Ford didn't want to encourage us to 'use' the last little bit - therefore they 'degrade' the go pedal and give us the good news : )

My son and I actually think that while there may be more power available, the software wants to really 'WARN' you not to continue, but when you put the truck in Park, it then 'releases' that power to allow you to move the vehicle out of the roadway, to a safe place. Nice.

 

[hturnerfamily]

I suspect when you got reduced power, the turtle icon was on your dashboard.

nope, no such 'turtle' icon ... that's for Nissan Leafs : )
we've never seen it on our Leafs, either.

 

[RickLightning]

I've had some close calls with my Mach-E, when I first got the 2021. One was when I was in Massachusetts, and skipped charging stations because I was stubborn. I forgot that the western Mass Pike actually is quite hilly. In fact, the highest elevation on I-90 after that point (1,724 feet) is in South Dakota. Made it fine, but got some warning messages.

Worse was approaching Erie, PA, going west on the NY Turnpike. Didn't want to exit and re-enter, was determined to make Erie. Again, hills. Got some warnings, the last one was similar to "you stupid moron, you need to find any outlet and plug this damn car in". I made it to Erie with 2% battery.

Now I rarely go below 10%.

 

[VTbuckeye]

And if you are in a safe area to do it, put your truck in drive attached to some tow straps and drag it around at low to moderate speed (someone will need to be in the truck) to give it a quick little charge. Essentially fake the truck into think that it is going downhill. If you couldn't make it up the driveway, maybe your son or the farmer across the street could have dragged to you around for a mile or two to add enough charge to get to the camper. This would be more acceptable off public roads due to the safety concerns and the manufacturer is not going to recommend it, but if the truck is on in drive it won't know whether gravity or another vehicle are providing energy.

 

[GarageMahal]

Wonder if the truck thought you were going down hill when you backed up the driveway

 

[davehu]

I hate to break it to you but going backwards probably has nothing to do with it.

If you watch other people who have run their EVs down to zero, there is often a period where after reaching no power, you can stop for a few minutes and then get a little power, then stop again, then get a little power, etc..

The system that is preventing you from depleting the battery to its real zero (to protect it) reads the voltage of the battery. When you stop for a few minutes, that voltage can bounce back a little because of the nature of batteries and the battery protection system allows a little more power. Eventually, the voltage will fall below the protection threshold permanently.

Your probably right. I have a slew of LIB battery powered tools. When my blower stops, for example, if I'm almost finished, I wait about 20 seconds and it has another 1-2 second blast then dies again. I can usually do this 2 or 3 times before it's totally dead.

That said, the story is pretty interesting and good to know.

 

[ivan256]

nope, no such 'turtle' icon ... that's for Nissan Leafs : )
we've never seen it on our Leafs, either.

I ran my battery down pretty low for the round-trip Thanksgiving run this weekend. As you approach zero and the voltage drops, you can see the "max power" on the output graph to the left of the guess-o-meter be reduced. At ~30% battery it said max power was 91%. At ~10% battery it was down to 41%.

I suspect this is a physical limitation. The battery probably does not have enough voltage at that point to give you the full 500+ horsepower.

 

[Beaux]

I've ran mine past zero twice. First time went about four miles after zero and no issues. Last week the range was reducing quickly approaching home. Turned everything off I could. Went 2 miles past zero and it went dead pulling into the garage. I had to plug it up to get charged enough to finish pulling it all the way in. Whew that was close!

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