At Home Level 2 Charging Experience from 7% to 90%

[DerMot]

Trip context
Over the weekend, I completed a round trip from London to Toronto and back, departing with 100% state of charge (SoC) and arriving home at 7% SoC. This provided a good real‑world test of my at‑home Level 2 charging setup after a longer highway drive. We had a huge headwind going there and averaged 40kWh/100kms on the way down and had 33kWh/100kms on the way home with the tailwind.

Home Charging setup

• Vehicle: 2024 Lightning Platinum (extended battery pack)
• Home charger: Grizzl-e Ultimate Level 2, 80‑amp capable -
• Typical observed charge rate: ~10.2–10.4 kW (per app)
• Charging schedule configured: 11:00 PM – 11:00 AM (12‑hour window) 11-7AM is the ultra-low rate
• Planned departure the next morning: 8:20 AM

My intent with this configuration was simple: give the truck a full overnight window to reach 90% without micromanaging timing.

What actually happened
I plugged the truck in at approximately 5:00 PM. Despite the scheduled charging window, the truck immediately began charging, bringing the battery from 7% to ~18% SoC. At that point, charging stopped and the app displayed “Waiting to charge”, resuming automatically at 11:00 PM, exactly as scheduled.
Charging continued overnight and completed at approximately 8:15 AM, reaching 90% SoC—just as the vehicle finished preconditioning the cabin ahead of my planned departure at 8:20AM.

The interesting part
What surprised me was that the truck clearly wasn’t just following a rigid start/stop schedule, it appeared to be intelligently managing charging to ensure the target SoC was reached precisely by my departure time.

Why this matters

• No need to manually calculate charge duration
• No need to override schedules or wake up early to check progress
• Vehicle was charged, preconditioned, and ready exactly when needed

Bottom line

This experience reinforced how at‑home Level 2 charging easily supports regional road trips. Plugging in at low SoC after a long drive and waking up to a ready‑to‑go vehicle without thinking about timing was seamless and surprisingly smart.

*Copilot AI helped get my points into a reasonable format.

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[K6CCC]

I did find it interesting that because the charge was so low that it started charging right away until it got to 18%. After it started charging at 2300, the timing was just about right for your departure. The truck does NOT regulate the charge current based on your departure time - it just charges at the full capacity of the lower limit of the on board charger or the EVSE. Your just over 10KW charge rate is about what you are going to get with a 48 amp charger - as far as I know, what your 2024 has.

 

[Maquis]

What happened is when you plugged in, the truck didn’t think it could reach the target in the charge window, so it started immediately. Then at some point, it realized it could do the remaining charge within the window, so it stopped and waited for the start time.
It does not throttle charging in order to finish at the departure time. If you plug in at 60%, it will charge full bore at the start time and stop at the charge target even if it’s hours before departure.

 

[TaxmanHog]

This process has been well known and observed early in the release of the Lightning, still happens with 2022 & 2023 trucks with ER capacity and dual on board chargers.

 

[bc1]

Well, I'm impressed. Can you make a similar round trip from Paris to Toronto?

 

[DerMot]

Well, I'm impressed. Can you make a similar round trip from Paris to Toronto?

lol Paris, Ontario - sure.

 

[potato]

Personally I freaking hate hate hate the fact that it doesn't observe my charging schedule. There is a very good reason I set it to not start until 11 p.m. and that is that it costs me $$$$$ (okay, $$) if it starts charge during the peak periods. If I arrive home with a low state of charge I specifically have to wait to plug it in, or mess with the target charge %, to make sure it doesn't start until 11.

It should NEVER automatically start outside your preferred times. It should ALWAYS be a manual user action for that. In my not so humble opinion.

Or perhaps best of both worlds they could have a switch for whether to try and outsmart the user or not.

 

[Timeless Epoch]

Was the 7-18% due to trying to meet the schedule or because the BMS didn't want the battery sitting at such a low SOC?

 

[DerMot]

Was the 7-18% due to trying to meet the schedule or because the BMS didn't want the battery sitting at such a low SOC?

I believe it was trying to meet the schedule.

 

[chl]

So a departure setting will override the normal time-of-day charging schedule. Good to know.
Be nice if there was a flow chart/decision tree for these things in the manual.

 

[TaxmanHog]

Personally I freaking hate hate hate the fact that it doesn't observe my charging schedule. There is a very good reason I set it to not start until 11 p.m. and that is that it costs me $$$$$ (okay, $$) if it starts charge during the peak periods. If I arrive home with a low state of charge I specifically have to wait to plug it in, or mess with the target charge %, to make sure it doesn't start until 11.

It should NEVER automatically start outside your preferred times. It should ALWAYS be a manual user action for that. In my not so humble opinion.

Or perhaps best of both worlds they could have a switch for whether to try and outsmart the user or not.

Just delete (or switch OFF) the departure events schedule, problem solved, though now you need to get it switched on later the next morning so that your battery warming (winter issue only) will be executed.

 

[potato]

Just delete (or switch OFF) the departure events schedule, problem solved, though now you need to get it switched on later the next morning so that your battery warming (winter issue only) will be executed.

That doesn't solve it, for me at least. I never use departure times. But if I plug in early and the truck doesn't think it can reach the target charge before the end of the charge window, it will start charging early.

Interestingly it will start early but it won't run late. It will stop at the end of the charge window and say "waiting to charge" if it hasn't yet reached the target.

 

[chl]

That doesn't solve it, for me at least. I never use departure times. But if I plug in early and the truck doesn't think it can reach the target charge before the end of the charge window, it will start charging early.

Interestingly it will start early but it won't run late. It will stop at the end of the charge window and say "waiting to charge" if it hasn't yet reached the target.

Good to know.

 

[TaxmanHog]

That doesn't solve it, for me at least. I never use departure times. But if I plug in early and the truck doesn't think it can reach the target charge before the end of the charge window, it will start charging early.

Interestingly it will start early but it won't run late. It will stop at the end of the charge window and say "waiting to charge" if it hasn't yet reached the target.

Ahh, I assumed you were, and that was the root cause.

When you plug in and it starts early, how long does the initial run last, more than a couple minutes ?

When I was using time limits, it would run for 30 seconds to a couple minutes to gauge the situation then pause and wait until the official start time later in the evening or early next morning.

Also, the prediction to override the start point is based on the primary goal that the SOC is at desired SOC by the end time, if you don't need the extra SOC, then lower it and again the problem can be solved.

 

[potato]

Ahh, I assumed you were, and that was the root cause.

When you plug in and it starts early, how long does the initial run last, more than a couple minutes ?

When I was using time limits, it would run for 30 seconds to a couple minutes to gauge the situation then pause and wait until the official start time later in the evening or early next morning.

Also, the prediction to override the start point is based on the primary goal that the SOC is at desired SOC by the end time, if you don't need the extra SOC, then lower it and again the problem can be solved.

I should try it again to see if anything has changed recently. I am using a different EVSE now, and there have been a few software updates.

The issue I had before - I think I've complained about this here - is that if the charge is just right, the truck will error out. I can charge about 45-50% during my 8 hour charge window. My target charge is 80%. So if I plug in at around 35-40%, the truck would start charging, decide that it didn't need to, and stop charging, then repeat. It would do this for about 2 minutes before reporting a charging fault. To clear this I'd have to either unplug and replug, or go in the app and change the target charge. Either of those things seem to cause it to re-run the code that decides if and when to start the charge.

Yes, adjusting the target charge lower to ensure it doesn't start early does work. I think I mentioned that workaround earlier. The problem there is a) that I have to do it in the first place, but mainly b) that I have to remember to go in and change it back at some point later.

So because of that I am in the habit of just not plugging in until late evening if I get home with a low state of charge. Not great but I usually do a bedtime dog walk anyway so I just plug it in on the way.

All this unnecessary thinking and workarounds that could just be avoided if they ALWAYS stuck to the charging window. They wouldn't even have to do it by default; if they just provided a switch to do so I'd be happy.

I don't want to experiment with how long the charge would run if it starts early, since it's an extra 5 or 10 cents/kWh

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