Drove It Past 0% - Success

My buddies and I decdied to head to the Hard Rock Casino north of Sacramento for the evening. I calculated that I had just enough charge to make it there and back. When I arrived I planned to plug into the free L2 charger, but of course they were all taken. On the way home I had the Ford navigation handle the trip back so I could monitor the range with the distance to destination on the instrument panel.

I don't know if I got confused, or if this is another "bug" in the software, but I could have sworn that the range is displayed on top of the distance to destination. I ended up ignoring all the warnings from the Mach-E telling me I didn't have enough range to get back and I chose not to stop for a quick 5 minute DC charge since the GOM showed I had a 3 mile buffer.

I didn't realize my mistake until I canceled the navigation and saw what I thought to be the range slowly disappear from the instrument panel. That 3 mile buffer actually turned out to be a 3 mile deficit!

When the car reached 0% and 0 miles on the GOM I got the dreaded "Battery depleated, stop safely now," warning. Fortunately after that happened I was able to make the extra 2.8 miles to the house just fine, which included a pretty significant hill. I turned off the headlights just in case that would help.

Good to know! Thanks for taking one for the team!

Nice, betting like an ICE vehicle there's a bit in reserve from what you'll see as far as range goes.

DanCoon said:

I could have sworn that the range is displayed on top of the distance to destination.

Click to expand...

I noticed that too. The display will flip the battery mileage and the destination mileage if it thinks you cannot reach the destination. Very confusing if you don’t notice the symbols are different than before.

I got down to 13% with 27 miles left to my house. The GOM was showing 30 miles of range. Decided not to take the risk and stopped for a DC charge.

Thanks, good to know.
But wondering -- does running below 0% harm the life of your battery pack?

Scooby24 said:

Nice, betting like an ICE vehicle there's a bit in reserve from what you'll see as far as range goes.

Click to expand...

Cobra427 said:

Thanks, good to know.But wondering -- does running below 0% harm the life of your battery pack?

Click to expand...

Not recommended for sure but it will affect range more than life. The key is don't let it sit there for long periods and quickly get it on a charger. Ford certainly protects their battery better than most. I'm very certain there is still charge available below that range that Ford will not allow access to.

At some point I plan to run my battery down as well to see where the true bottom is and how the car responds.

Road tripped from Edmonds (20min North of Seattle) to Portland, OR and back last weekend. Charged to 100% before leaving, hit a fair amount of stop and go traffic on the way down. Made it down there Ez with 15% charge left on battery. Hotel valet folk plugged it in overnight (I remembered to bring fob as I’m all in on PaaK?) and we drove around a bit downtown Pdx using 5% up before getting to our in-laws place where we stayed over for the night. Left with 95% charge the next morning for the drive home. Nav said we’d have 40 miles of range once I arrived home. There was little to no traffic at all the whole way, so no regen. The 40 mile buffer was decreasing constantly and consistently the whole 3 hour drive but it was looking like it would be just enough. I won’t say it was white knuckle when we were passing thru Seattle as it seemed like it’d be about 12 miles of range left. 10 miles left! Not too shabby. I have the ‘small‘ battery…also Portland was RUFF. That town is looking very shabby. Extremely sad to see.

DanCoon said:

I ended up ignoring all the warnings from the Mach-E telling me I didn't have enough range to get back and I chose not to stop for a quick 5 minute DC charge since the GOM showed I had a 3 mile buffer.

Click to expand...

I'm curious about two things. Was it difficult to ignore all of the warnings? How long have you owned your MME?

It would be nice to take HV battery voltage readings at the start of 0% reported battery. With that knowledge we could calculate how much low end buffer Ford is showing. The voltages a cell can achieve is an exact science. Easy enough to figure out with the details.

IL_Vet said:

I'm curious about two things. Was it difficult to ignore all of the warnings? How long have you owned your MME?

Click to expand...

I've had my Mach-E since the last week of March. The warnings weren't difficult to ignore. I earned a lot of experience in how the computer notifies you of range, etc. on my last big road trip. I take it with a grain of salt when it starts telling me there are no chargers within range because the Ford Navigation doesn't seem to be as up-to-date as you might think.

I only really started to worry when I saw the "Depleted battery notification," as that was unmarked territory for me so far, but now I know.

T_to the_A said:

Road tripped from Edmonds (20min North of Seattle) to Portland, OR and back last weekend. Charged to 100% before leaving, hit a fair amount of stop and go traffic on the way down. Made it down there Ez with 15% charge left on battery. Hotel valet folk plugged it in overnight (I remembered to bring fob as I’m all in on PaaK?) and we drove around a bit downtown Pdx using 5% up before getting to our in-laws place where we stayed over for the night. Left with 95% charge the next morning for the drive home. Nav said we’d have 40 miles of range once I arrived home. There was little to no traffic at all the whole way, so no regen. The 40 mile buffer was decreasing constantly and consistently the whole 3 hour drive but it was looking like it would be just enough. I won’t say it was white knuckle when we were passing thru Seattle as it seemed like it’d be about 12 miles of range left. 10 miles left! Not too shabby. I have the ‘small‘ battery…also Portland was RUFF. That town is looking very shabby. Extremely sad to see.

Click to expand...

Nice trip summary. Just wanna add a perspective, your range is actually better if you don’t have to stop-resume-stop-resume due to traffic because regen only is able to recapture a fraction of the energy the car is using to get up to/maintain speed. HOWEVER, traffic might still functionally give you better range because if you are forced to slow to 20-50mph, up and down through traffic, that's still likely to be much more efficient than cruising at say 80mph on an open freeway, since high speeds are where BEVs are least efficient.

Cobra427 said:

Thanks, good to know.
But wondering -- does running below 0% harm the life of your battery pack?

Click to expand...

Yes, running the pack down below 10% can start to degrade the battery. Driving below 0% should be for dire situations only, and if you ever get there you should be kicking yourself for being a dumb-dumb missing the warnings and hurting your expensive battery.

The folks that like to run it down into the the single digits should be aware of the battery health consequences. Once it gets down to ~25 miles range left you should be heading straight to a charging station and not driving around more. Don't be a Kramer.

For daily use, battery should stay between 20-90%. Past that is for occasional trips a couple times per month or less to limit battery stress.