Auto-stop charging at 80%?

I'm considering buying a 2022/2021 Leaf, but from what I've heard it doesn't have the feature to auto-stop charging at 80%.
Is that correct?

What does everyone do? Do you go down and manually disconnect it when it gets close to 80%?

I heard only charging to 80% increases the battery lifespan in the long-term, so I'd like to do it to keep my range as long as possible.

Thoughts?

What the Leaf does have is a timer- we have ours set to charge for five hours off-peak (12 AM till 5 AM) which adds about 30% to the state of charge. We only plug it in when it gets below 30 or 40 so it never gets above 70% or so, unless we are planning a trip in which case you can override the built-in timer and top it off overnight. When traveling, you have to decide if you want to wait around to get a full charge (the charging slows considerably after about 80%) or take the 80% and get on the road.....

dmacarthur said:

What the Leaf does have is a timer- we have ours set to charge for five hours off-peak (12 AM till 5 AM) which adds about 30% to the state of charge. We only plug it in when it gets below 30 or 40 so it never gets above 70% or so, unless we are planning a trip in which case you can override the built-in timer and top it off overnight. When traveling, you have to decide if you want to wait around to get a full charge (the charging slows considerably after about 80%) or take the 80% and get on the road.....

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Thank you for the reply!

When you leave it unplugged, is there any kind of trickle drain on the battery?

The vampire drain actually occurs when you leave the car plugged in after charging ends, not if you leave it unplugged. Most Leafs will keep their 12 volt batteries charged, and don't lose much charge from the main pack, when sitting unplugged. Just don't leave anything plugged into the diagnostic port under the left side of the dashboard.

abeadoobu33 said:

I heard only charging to 80% increases the battery lifespan in the long-term, so I'd like to do it to keep my range as long as possible.

Thoughts?

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It does in the grand scheme of things but as what other manufactures are doing, your can't truly charge the battery to 100% of it's rated capacity, so for example, the 62 kWh Leaf is reported to only allow 56 kWh of usage from that, so even if the dash says it's 100% charged, it's really only 90% charged. :lol:
Now for people like my wife who drives her Leaf like she did her old gas car, she just keeps the car at 100% all the time and while I ask her not to do that she hasn't listened to me for years and her battery is still is good shape after 3.5 years, so she probably thinks I don't know what I'm talking about at this point. :roll:

abeadoobu33 said:

I'm considering buying a 2022/2021 Leaf, but from what I've heard it doesn't have the feature to auto-stop charging at 80%.
Is that correct?

What does everyone do? Do you go down and manually disconnect it when it gets close to 80%?

Click to expand...

Correct, that "80% feature" is not available on the Leaf.

I have been using the Timer on mine for years now to control the charging. I've gotten used to knowing how my EV charges, and what types of trips I need to make per week, so I know when to plug it in at home. I only set it up to charge above 80% if I know I will be driving a lot the next day.

Just use the charge timer. Takes a little getting used to but eventually it gets pretty easy.

Leafs have hardly any vampire drain. Our tesla has much higher vampire drain but there is also a lot more going on.

The leaf is a great car. Enjoy.

To put this another way: use the charge timer (or just choose when to plug the car in) so that you can unplug it right before you need it, as it reaches about 80%. The easiest way is to set the charge timer for an end time two hours or so AFTER you will be leaving. Then make sure to deselect the "Full Charge Priority" option in the menu, to prevent the car from "fixing" your "mistake" in setting the timer.

LeftieBiker said:

To put this another way: use the charge timer (or just choose when to plug the car in) so that you can unplug it right before you need it, as it reaches about 80%. The easiest way is to set the charge timer for an end time two hours or so AFTER you will be leaving. Then make sure to deselect the "Full Charge Priority" option in the menu, to prevent the car from "fixing" your "mistake" in setting the timer.

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Now that is very creative, I hadn't thought of that! :mrgreen:
So basically, since your L2 is always going to charge at the same rate, the Leaf will use that delayed time for it's "start" calculation and since you set it 2 hours "after" when you would want it ready, that delay will always mean that it will probably be at the same SOC since it takes into account time to balance the cells (which is probably another hour after it reaches near 100%). So it wouldn't matter what SOC it was in before you set the timer (20%, 40%, 60%, etc.), it will always just push back the start time to hit 100% at your set timer goal, very clever! :lol:

So for example, I leave at 8am to go to work for example, 5 days a week. I don't need 100% charge to go back and forth to work. I set the charge timer to have the car "ready" by 10am. No matter what SOC the Leaf is in before night time, the car will always start at some point in the night depending on the current SOC so that the goal is to reach 100% by 10am. But since I am leaving at 8am instead, the Leaf will probably be around the 80%-ish SOC mark when I actually leave, regardless if it was 60%, 35%, or 5% the night before.

I'd like to take credit for the idea, but others came up with it. What I personally do, to avoid messing with the timers, is do a rough calculation of how many hours the car will need to charge to get to where I want it (usually about 60-70%), and then plug the car in at the correct time to get there. Then, I leave a note for my housemate to unplug it at a convenient time that I have also included in my mental arithmetic. It sounds harder than it is. And we still, with 40kwh and 62kwh Leafs, use L-1 charging!

LeftieBiker said:

The easiest way is to set the charge timer for an end time two hours or so AFTER you will be leaving.

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Is there actually a way to only set the end time and get the car to calculate the start time such that it will reach 100%? I can't figure out how. I always have to set the start time myself. Which means I'm doing all the math in my head anyway. At 10% per hour it's easy math. But if there's a way to get the car to do the math, that would be cool.

That used to be possible - it used to be the easiest way to get a full charge. I haven't done much with the new version of the timer, but I THINK that if you make sure that 'Full Charge Priority' or whatever it's called, is checked, the car will do what you ask regardless of what the timer setting is.

LeftieBiker said:

That used to be possible - it used to be the easiest way to get a full charge. I haven't done much with the new version of the timer, but I THINK that if you make sure that 'Full Charge Priority' or whatever it's called, is checked, the car will do what you ask regardless of what the timer setting is.

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Okay, I played with it a bit and here's how it behaves. Enable "Full charge has priority " and don't give it enough time between start and end to reach full. The car will attempt to satisfy the full charge by moving the effective start time earlier for you. I can use this method to accomplish what you suggest. By intentionally setting the start time near the end time and letting the feature move the effective start time.

If there's not enough time between now and the end time to reach full then the feature will start charging immediately and also push back the effective end time to reach full.

Yup. If you can do it on a schedule then that's probably the easiest way to get less than a full charge.

I personally find using the timer as easy as anything, and usually wake up to it within 2% of what I was aiming for charge wise. Veryuch good enough for 99% of use cases from my end.

DougWantsALeaf said:

I personally find using the timer as easy as anything, and usually wake up to it within 2% of what I was aiming for charge wise. Veryuch good enough for 99% of use cases from my end.

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The charge timer certainly has value in delaying a charge until I want it to happen. If the battery was resistant to degradation due to time at high SOC then the timer alone would be acceptable. And while Nissan/AESC have been improving the cell robustness, this is still a significant concern. Consider the following cases that could lead to a unnecessary charge to 100%, possibly followed by a long resting time at 100%:

1) I make a mistake in setting the charge timer (like set p.m. instead of a.m.)
2) I accidentally leave the car plugged in a 2nd night when I didn't drive it the previous day.
3) I plan to unplug the car, but am unavoidably detained from returning to the car (emergency).
4) Someone more careless than me drives the car and just plugs it in regardless of SOC.
5) I want the cell balancing to run periodically. The BMS could be smart enough to do this at 80% if it knew that 80% was the end of charge. But with a Leaf, you have to charge it to 100% and leave it there for over at least a couple of hours.

Plus the simple frustration of having to fiddle with the charge timer, buried down in the menus, to hit the charge I want. And I haven't yet covered the increased risk that I might forget to charge when I need to. I find myself checking SOC almost every time I pull into the garage and often deciding not to plug in because it's probably good enough. But what if I forgot I have an unusual trip tomorrow? Or just the habit of intentionally not plugging in causes me to be more likely to accidentally not plug in when I need it. Ugh!

The Leaf would be much better with a selectable charge termination level (in % SOC). Set it and forget it. Plug it in anytime or every time, without needing to engage your brain or teach your family. Lower effort. Fewer mistakes. Without selectable charge termination you have to decide - Will I put in the effort to manage SOC less than 100%? Or will I just charge to 100% and suffer the aggressive SOH loss.

Snargleblarg said:

The charge timer certainly has value in delaying a charge until I want it to happen. If the battery was resistant to degradation due to time at high SOC then the timer alone would be acceptable. And while Nissan/AESC have been improving the cell robustness, this is still a significant concern. Consider the following cases that could lead to a unnecessary charge to 100%, possibly followed by a long resting time at 100%:

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This isn't a nitpick of your reasons, they are all valid in my opinion. One thing to keep in mind is 100% SOC on the dash is not really 100%, it's actually closer to 90%, even when brand new. So while it still fits into keeping the charge level at 80% or lower, at least in the long term sense, the damage caused by being at 100% is probably much less due to Nissan keeping anyone from charging the battery to a true 100% SOC. I'm starting to think this is having some effect because my wife is terrible with her Leaf. It's a 2018 with the 40 kwH pack and she keeps it at 100% SOC all the time like it was a cell phone or something. 3.5 years of this and my wife's battery is still at +92% SOH. (link to that screenshot here -> https://mynissanleaf.com/viewtopic.php?f=9&t=25773&start=1210 ) That's why I feel that heat is probably having a more harmful effect over the long term than state of charge, but I guess we will know for certain in another couple of years once the battery hits the magical 7 year mark on age.

knightmb said:

One thing to keep in mind is 100% SOC on the dash is not really 100%, it's actually closer to 90%, even when brand new.

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How do you figure ?

Both LeafSpy and, IIRC, the cell voltages indicate a SOC in the mid to high nineties when the dash shows 100%.

SageBrush said:

knightmb said:

One thing to keep in mind is 100% SOC on the dash is not really 100%, it's actually closer to 90%, even when brand new.

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How do you figure ?

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You can't see it on the dash, but with the help of LeafSpy, using mine as an example. The *dash* says that the battery is at 100% SOC, but checking LeafSpy shows it's only around +56 kWh out of the 62 kWh capacity. 56/62 = .90322 or roughly 90% total charge capacity out the max total. If I keep *balancing* the cells at the top, I can squeeze in a little more, like 56.3 kWh or 56.8 kWh I did one time by constantly starting a charge session even when the dash said 100% :lol:

Another *hmm* moment is when you charge it up to around 98% on the dash, go to unplug it, start the Leaf and it magically jumps to 100% :mrgreen:

The only way to reach the actually max capacity of the battery would be to charge each cell to as close as 4.3 volts as possible without going over to avoid a true 100% charge damage. I don't think any manufacture is going to have a BMS do that, too many things could probably go wrong with so many cells.