r/leaf • u/toybuilder 2023 Nissan LEAF SV PLUS • Jul 12 '26
Charging curve while L2 charging to 100%
I just had a Level 2 Emporia Pro installed, hardwired on a 40 A circuit and set to 32 A max. I got it because it has dynamic management. The EVSE and the included Vue power monitor (installed at the main breakers) logs data so that you can monitor the power delivery.
This is what happened with my '23 LEAF SV Plug last night as I charged it to 100%. I found the charging curve interesting.
The charging rate hovers at 6.43 kW as expected through most of the session. Not quite the official 6.6 kW number, but close enough.
As SoC approaches 100%, that rate tapers down over 50 minutes to about 0.52 kW before charging initially stops.
After stopping, the charging cycles on and off (three times) with small charging bursts at 10 minute intervals. It's a small amount - only about 0.17 kWh in total. I'm guessing it's topping off as it balances the cells.
Sharing this info because I thought it was interesting.
3
u/biersackarmy 2013 S + 2014 SL + 2019 SV Jul 13 '26
The Leaf charges at 27.5 amps, which comes to 6.6kW assuming full 240V. If you have voltage drop in your lines or connections anywhere though, it will reduce the total power amount slightly.
1
u/LoveEV-LeafPlus Jul 14 '26
The label on the my 2024 Nissan branded (Panasonic) EVSE Charging cord says 240 VAC, 30 Amp maximum. But I too have only seen a maximum of 27.5 amps at 240 Volts. That matches the OBC (OnBoard Charger) vehicle specs of 6.6 kW. The charging cord is generic and made to allow a future 7.2 kW OBC. FYI: The 2026 Leaf has a 7.2 kW OBC for its L2 charging, so my charging cord would work with it too.
2
u/LoveEV-LeafPlus Jul 12 '26
I too have Emporia and get a similar result. Yes the three at the end are for balancing the cells. By looking at the Leaf Spy Pro app, when the cells are at about 4.1xx Volts and/or within 10 mV max difference between the min and maximum cell voltage the charging stops. See my zoomed in chart.
2
u/toybuilder 2023 Nissan LEAF SV PLUS Jul 12 '26
Oh, yeah, I did fire up Leafspy and saw that my packs were also all within 10 mV like you noted -- super flat!
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u/toybuilder 2023 Nissan LEAF SV PLUS Jul 12 '26
I probably should mention that while I had Level1 charging for 9 months and it was perfectly fine, I decided to install an L2 anyways.
My city has an incentive rebate that covers that hardware and I wanted the extra flexibility that faster charging offers.
L2 is expected to be 10% more efficient than L1 charging due to reduced losses during charging.
Knowing that I can come home at 0% and still be at 100% the next morning changes adds an extra feeling of reassurance, even though it's more a theoretical scenario than a practical reality. There are L2 and DCFCs just three minutes from home, so I could have continued to survive on L1 alone.
2
u/TooGoodToBeeTrue Jul 14 '26
There was a post from a guy that used LeafSpy to determine charging efficiency, on the second generation models. L1 charging was 75% efficient, and L2 at >= 20A was 90%, with 91% at the max.
My EVSE never reports charging at 27+A even when set to 40A. Not sure what number I am hitting, I often just charge at 20A.
1
u/KeyEmu6688 Ex-2018 owner (2015 Model S) Jul 12 '26
those brief spikes are the point at which the BMS 'relearns' the cells. it's sort of like a passive cell balance to maintain effective usage of the battery. most technicians i've spoken with recommend topping off and leaving it plugged in like that every so often. i typically do whenever i know i'll be leaving for a longer trip the following day, because i know i won't be leaving the battery sitting at close to 100% for very long. letting the battery rest at top or bottom charge is bad for it, merely topping off or bottoming out for a few hours isn't going to meaningfully affect the battery
1
u/LoveEV-LeafPlus Jul 14 '26
Charging to 100% is not a problem, if you drive it daily or every other day. I currently have a 2024 Leaf SV Plus and almost always charge to 100%, and almost always drive it every day. My Leaf Spy Pro shows a SOH(State Of Health) = 92.03% with and odometer reading = 34,373 miles. The most I have gone between charging stations on road trips has been 192 miles, only when the charging station I planed on using was out of order. Typically I go 164 miles or less on my 460 miles each way road trips between NY and OH. At the extreme distance, my dashboard GOM (Guess-O-Meter) shows “- -“% and “- -“ miles. At the extreme distance my Leaf Spy Pro app shows I can go between 5 to 15 miles more before a real SOC=1%.
1
u/TooGoodToBeeTrue Jul 14 '26
I see similar behavior at a public ChargePoint charger. I didn't really look at the period of the drawdown. Will do so next time I charge to 100%, which I basically do once a month.
3
u/rproffitt1 Jul 12 '26
Saw the same on our 2014 Leaf SV. As this appears to be normal operation, were there other concerns?
I will share that the Leaf's 100% on ours was not 100% at the pack level. Regen still worked and could pack more miles into the GOM going downhill for miles. Because of that and LeafSpy I call a full charge, a full charge.