Charging 100% thoughts?

[ryun]

My honest opinion on this is if charging to 100% makes you feel better about your commute then just charge to 100%. It's not a big deal. Just make sure you're using it shortly after reaching 100% and that your truck isn't baking in the sun at 100% for hours on end.

If you can get away with less than do it, but don't sacrifice your needs for it.

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[unshortness]

I’m new to this but I’ve paid attention to the 100% posts pretty close. Things I’ve remembered. Once you hit 80%, your charge rate is reduced significantly. So to go from 80 to 100 will take about as long as 40 to 80 +/-. They say to stay between 80 and 20 for best longevity. Then they also mention your battery may need reconditioning periodically. To accomplish that you need to run it down to 20 or lower and then recharge to 100 and do that a few times. That apparently balances all the batteries out so the charge and discharge evenly.
I love my Flash! Have a great day.

This throttling is true for DC fast charging. On my 2024 flash the second it hit 80% charged the speed of the charging dropped in half. I don't think the truck will slow down the charge at all on Level 1 or 2 AC charging, that will charge basically the same speed all the way up to 100%. It might slow down for the last 1-2% but the majority of the charge will be at whatever speed your Level 1/2 charger is.

 

[Davem]

I have charged mine to 100% 4 times a week since I purchased it in 2022 because my commute is 100+ miles round trip. Recently had the truck to the dealership for a few recalls and my SOH shows 99% according to them. I'm slightly skeptical, but I think running the battery down to 10% every week has helped.

Lol

 

[Dspade]

That is for DC fast charging.

For AC charging, the charge rate is pretty constant until a little before it is finished when it will ramp down at the end (see end of last night's charge below, EVSE was set to deliver 30A).

When charging to 100%, it will get to 99% ramp down to a lower power level for an hour or two while the battery management system performs a full cell rebalancing.

That is for DC fast charging.

For AC charging, the charge rate is pretty constant until a little before it is finished when it will ramp down at the end (see end of last night's charge below, EVSE was set to deliver 30A).

When charging to 100%, it will get to 99% ramp down to a lower power level for an hour or two while the battery management system performs a full cell rebalancing.

I knew I was close in my comment, but it would've taken me all day to analyze it. If you guys don't use AI, get it! Here's my analysis using Claude:

Good data, Calvin — I think we're both right, and your 30A detail explains it.

I ran the numbers on my own sessions (2025 Lightning ER, Grizzl-E at 48A/240V):

Level 2 home charging:

1. 41% to 100% — 9 hrs 33 min — 72.6 kWh
2. 40% to 80% — 4 hrs 59 min — 51.7 kWh
3. 76% to 100% — 5 hrs 14 min — 29.5 kWh
4. 39% to 80% — 5 hrs 10 min — 53.6 kWh
5. 2% to 74% — 8 hrs 34 min — 87.7 kWh
6. 52% to 100% — 7 hrs 46 min — 59 kWh

Below 80%, every session averages a constant 10.2–10.4 kW — maxed out, just like your flat line. But every session that ran to 100% averages way less at the top: comparing #1 vs #2 (same start point), the 80–100% stretch took ~4.6 hours for ~21 kWh — only ~4.6 kW average.

Your post explains where that time goes. If the truck holds full rate into the mid-90s and then spends 1–2 hours at low power doing cell balancing after 99% (as your graph shows), the math on my sessions works out almost exactly. So the "slow top end" I was seeing is mostly that balancing tail, not a gradual taper starting at 80%.

And the reason your graph looks perfectly flat while my averages sag: at 30A you're delivering ~7 kW, which is below wherever the Lightning's AC curve dips until the very end. At 48A (~11.5 kW) I'd catch any pullback under 11.5 kW that your setup can't display.

Bottom line for anyone reading: on the Lightning, DC fast charging tapers hard after 80% (my Supercharger data: ~139 kW avg from 21%, ~19 kW from 95–99%). Level 2 holds essentially constant until the high 90s, then plan on an extra hour or two of low-power balancing if you charge to 100%. Which is exactly what the next comment said after us. Have a great day!

 

[Joe Dablock]

I have a 22 MME at 83k and a 23 Lightning at 63k and I charge both to 100% every time and seldom let them drop below 50%. The MME often only is reaching 290 miles at 100% charge, but the Lightning is always over 300 miles at 100%. Ask me again in a year.

 

[RLXXI]

I only charge twice a month so I usually go to 85-90 and 100% every... when I can remember lol. Last time I went 100% I gained an extra 25 miles somehow. Others have noticed it as well and realized it was part of the gateway module update something to do with how the truck reports usage accuracy or some such thing.

 

[MaintGrl]

I've only been doing level 2 charging to 90% from 70 to 80%, But it seems as I do multiple charges over time, the GOM keeps dropping by several miles was last down to 193 to 199 GOM. Just recently ran the truck down to 15% and charged up to 100%, that got me to 240 on the GOM. So, go ahead with the 90%, but do a !00% occasionally....IMHO

 

[Peddyr]

Lol

Glad I could give you a chuckle........about.....?

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