Drive until empty

[Sinclair63]

I just read an article about running a Lucid until it used all its battery energy and what they learned about the test.
Back in the day, I used to test my ICE cars to see how far I could run after it's indicated empty or zero miles left. I kept a small gas can with me to make it home. Most vehicles had 20 to 40 miles of reserve in the tank. Don't ask why, just a little ocd.
My question is two part. Has anyone experienced an event where you couldn't find a charger while out on the road and your Mach E ran empty? How far did it go past zero charge? And what issues did you encounter to get it up and running again?
For the record I never plan on doing this, but S#%t happens. I charge 100% of the time at home. And drive a 2022Mach E GTPE with @10k miles with absolutely no issues so far!

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[ocdxfv]

I once drove my MME down to 0%, 0 miles, then continued driving around the neighborhood until I lost my nerve. When I finally pulled into the garage I had gone about 5 miles.

 

[Mach-Lee]

I just read an article about running a Lucid until it used all its battery energy and what they learned about the test.
Back in the day, I used to test my ICE cars to see how far I could run after it's indicated empty or zero miles left. I kept a small gas can with me to make it home. Most vehicles had 20 to 40 miles of reserve in the tank. Don't ask why, just a little ocd.
My question is two part. Has anyone experienced an event where you couldn't find a charger while out on the road and your Mach E ran empty? How far did it go past zero charge? And what issues did you encounter to get it up and running again?
For the record I never plan on doing this, but S#%t happens. I charge 100% of the time at home. And drive a 2022Mach E GTPE with @10k miles with absolutely no issues so far!

The number of miles you get past 0% is HIGHLY variable and depends on a lot of factors. I wouldn't count on getting more than 5 miles past 0%. There have been some dumb people that got stranded trying to go 5+ miles past 0% because they heard a rumor on the internet that it goes further. Definitely a FAAFO situation for some.

 

[markboris]

I once drove my Mach-E down to 0%, 0 miles, then continued driving around the neighborhood until I lost my nerve. When I finally pulled into the garage I had gone about 5 miles.

Same here. I was at 0 SOC and 0 miles when I was about 5 miles from home. That only happened once about a year and a half ago but at least I know it can happen.

 

[Sinclair63]

I hope I never get in that situation to have to test it, but have seen a lot of EVs stranded on the road between Savannah Ga and Brunswick, GA ( about an 80 mile run) where I commute a couple times a week. Not sure they pushed it to far, or just had other issues, but there are almost no charging stations between the two cities.

 

[Mach-Lee]

I hope I never get in that situation to have to test it, but have seen a lot of EVs stranded on the road between Savannah Ga and Brunswick, GA ( about an 80 mile run) where I commute a couple times a week. Not sure they pushed it to far, or just had other issues, but there are almost no charging stations between the two cities.

Yeah looks like that's a larger gap between chargers compared to the surrounding area, so I'm sure people try to push it rather than turning around.

 

[AliRafiee]

it went 10 miles after 0 miles indicated.

 

[Vulnox]

A big part of how far below 0 you can go is BMS calibration. There isn't a way to know the actual amount the batteries are holding in kWh, so they get around it by having the BMS track how much goes in and how much goes out. It's a fairly reliable process, but over time the BMS can have "sway" if it falls far enough out of calibration. There are some other metrics that help, like pack voltage, to give an idea of current state of charge.

So as was already said, you can go some amount below 0, typically, but definitely don't take others results as a safety net. It is interesting seeing some of the range tests by YouTubers like State of Charge or Out of Spec where they drive to 0% and keep going for a bit. I just watched the Rivian Large/Max pack comparison on OOS and I think they had about another 5kWh below 0% from their calculations. On a Rivian that's only 10-12 miles though.

 

[KidGalahad]

My first time driving in below zero weather led me to this situation. I was driving to my parents house, my Mach-E was charged to 90% in my garage, with an estimated 190 miles range. I put my parents location in the nav, 128 miles away, and it adjusted (due to driving conditions) with a new estimation of around 150 mile range. As i started driving, I noticed the gap between range and remaining was getting lower and lower, with no charging stations available. I got to 0 miles range around 4 miles out, and did make it to my destination. The last 45 minutes was stretched out to about 90 minutes, with no heat or anything extra running, and going around 35 mph. Not a fun experience.

 

[Sinclair63]

it went 10 miles after 0 miles indicated.

Great video on the topic.

 

[hack-e]

Very good information. Lowest I ever got was 4%.

 

[jdsimard2012]

Kudos to those brave enough to try this. Very reassuring that there is a small safety margin past 0.

 

[ckt]

I drove to 1% yesterday on my select. The bms says 7% hvb degradation.

 

[ReverendPete]

Here's another interesting article that I have posted before: https://www.moveelectric.com/e-cars/what-happens-when-electric-car-runs-out-battery

 

[Sinclair63]

I drove to 1% yesterday on my select. The bms says 7% hvb degradation.

Not having any Electrical background, can you explain the 7% hvb degradation?

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