Best charging strategy for 10-mile daily commuter

My wife has a 10-mile round-trip commute every day. She occasionally runs errands that add a few miles, but most weeks could probably go for the whole week (or nearly so) without recharging.

What is our best strategy for prolonging the battery life?

• Charge every night? (We currently have the timer set with the end time just before she leaves for work.)
  
• Charge when it gets below a certain point? What point?
  
• Something else?

So far, we've just been charging every few days, when it shows less than about 30 miles of range.

FYI: we are using L-1 charging at home.

Although your experiences and opinions are welcome, I'd prefer authoritative sources of scientific/empirical data, if possible.

Thanks.

I was about to say what i did, then I read "I'd prefer authoritative sources of scientific/empirical data". then thought, well, I'll leave it up to you.

I only do 25 miles per day.

My Leaf is the 2012 SL

I set it on a timer to start at 2:30am stop at 80% charge (that year can do that)

I plug it in every other day unless I suspect I might have a meeting out of the office the next day.

Once a Week i charge it to 100% so it's nice and full for Saturday morning.

I have read that leaving it with less than 20% isn't harmful but when it goes in to 'Low Battery Charge' you should put it back up again as soon as you can. that is all I had that was smart to add.

Try to keep the state of charge between 30% and 80%, with occasional charges to 100% that end right before the car is used. Those are to equalize the cells in the pack. So if there is more than 50% in the pack, don't bother to charge until it gets down to about 30%, at which point try for 80%.

First of all, I would say... Don't over-think this. Yes, do not let the car go below 30%. I understand that the Leaf lithium batteries really like to be at 50%, unlike a lead-acid battery that lasts much longer at 100%. I have 25K miles on my 2 year old leaf, and got tired of the daily headache of ONLY CHARGING IT TO 80%. That requires timers, mental calculation, and other crap like that. After 2 years of charging the car to 100% (starting at about 40% every day) my battery is still at 100% Health, and as strong as when it was new.

So, you will not get an "authoritative data" unless you talk to some Japanese guy in Asia. I am an informed auto owner for 40 years experience and suggest the following: Charge up the car o 100% every time. The charger will automatically turn off to prevent overcharging. Drive the car for a few days until you reach 40-50%, and then charge it again to 100%. Quick, easy, and in my opinion the smartest use of your mental time. The other way, you will go CRAZY for nothing. When I first got my Leaf, for six months I used the 120v charger (on a timer) to only reach the "magic 80%" number and I hated it. Enjoy your car and don't baby it like it is a delicate flower!!

PS - invest in a 240v charger. With your driving habits, you will charge the car in 1-2 hours, and your car will be fully available to you all day and night long...

Your best source of all things battery-related can be found here:
http://batteryuniversity.com/

For lithium batteries, it is better to do 2 half-cycles than a single full-cycle. But you also want to keep it in the middle of the range. For such little use, that could be 40-60%. If you wanted to baby it based on the best data, you should charge it every night, but only up to 60%. Also, make sure you only charge late into the night, when the battery has had plenty of time to cool off. Since Nissan does allow you to set up such a charging schedule automatically, you would have to play around with timers, etc. Good luck with that.

In terms of practical usage, I agree with powersurge. Just use the car. Charge it when it's convenient. Every night is fine. Once a week may be better (so it doesn't sit at a high SoC).

The irony here is that, with such a short commute, your car will remain useful to you even with a lot of degradation. So use the car. Enjoy it. And don't over think it.

GetOffYourGas said:

...... And don't over think it.

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Which is why I find the 80% option so useful, especially if you don't need the range of a 100% full charge. Now I don't know if the OP has a '13 or even a '11 or '12 where charging to 80% is very easy but even on a newer Leaf I'd have to believe using the timer(and a known departure time) it would be pretty easy to stop charging at ~80%.
Sure you could always charge to 100% but then I'd have to ask why Nissan originally offered the 80% option and called it long life mode(or something to that effect) and only removed it because of the idioc way the range was calculated. No I'd say unless you really need the range of a 100% charge to at least stop at 80% but occasionally(weekly, bi weekly??) charge up to 100% to ballance the cells.
Note leaving the EVSE plugged in and hooked to the car 100% of the time isn't good either, from everything I've read it's a sure way to kill your 12v battery.

I'm a big fan of the "don't over-think it" strategy as well. I started off using 80% or less. After a couple trips that required charging, but wouldn't have had I been at 100%, I switched to 100% daily. Sometimes I use the charge timer, but most of my trips are random so it doesn't really fit well.

Note leaving the EVSE plugged in and hooked to the car 100% of the time isn't good either, from everything I've read it's a sure way to kill your 12v battery.

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Since the OP said this is a daily commute, I don't believe this applies. This was in reference to cars left plugged in for extended periods of time (weeks) IIRC.

My guess is your wife will be happier if she doesn't have to play games with the charging...

Great advice everyone! I want to add something that most people don't realize: 50% SOC is NOT 6 bars out of 12. When using LeafSpy, I find that with my 2011 it is closer to 4-5 bars. Thus, if you really only need 10 mi daily, you can easily use the car in the 3-5 bar range. I "try" to do this on a routine basis, but once or twice a month I charge to 100% and then immediately do a longer (~30 mi) trip. Again, don't over think it or worry too much. Ultimately, us low mileage drivers will see much more calendar and temperature degradation than cycling degradation. I was hoping that the battery would last much longer with my low mileage, in-town, easy charging operations. Unfortunately, it is degrading just the same.

If it were me, I'd simply charge it every night, and not worry. That way the car is always ready with maximum range. You never know when someone will get sick and you suddenly need to drive a bunch. If the car had an 80% mode, I'd use it, but since yours doesn't, just let it charge to 100%.

It's ridiculous to constantly compromise your life trying to baby a battery...especially since it has not been shown on here that any of it does much good.

Thanks everyone. Having read a fair amount of the tech talk here, I assumed that someone had figured out the optimal charging strategy for every possible scenario.

I'm okay with charging whenever it seems to be a good idea, but I half expected that if I said here that we put it on the charger every night after only traveling 10 miles, or let it go until it's down to 20%, that someone would tell me I was killing the battery, and that I should do the opposite.

Our Leaf does have the 80% charge option, and we've set the timer to finish at about the time we wake up. My wife is slowly getting over her range anxiety, so she'll go at least two or three days between charging if it isn't too low. I'll tell her that's okay.

Thanks again.

I forgot to mention that I park the Leaf outside at night (desert cooling effect) in the summer. On those nights I don't charge (I mostly bicycle in the summer anyway) and the battery stays much cooler. On the nights that I do charge, the battery stays about 10 F warmer. Again, it probably won't make much difference in battery life, but my driving needs around town are normally less than 10 mi, and I pay $0.06/kWh 24/7, so I can always plug in anytime. As for emergencies, I have delayed a couple of trips, cancelled a few, and maybe driven the gasser one extra time in 5+ years. I did cut it pretty close a few times because I decided to drive at the last minute, but really zero "emergencies." I know this doesn't work for most people, but in my small town, it's pretty easy, especially since most driving is at 35-40 mph.

Our Leaf does have the 80% charge option, and we've set the timer to finish at about the time we wake up.

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You don't need to do that with the 80% charge. I let mine sit for days - even a week, occasionally - at 80% and I still have 12 bars on my '13.

commasense said:

... What is our best strategy for prolonging the battery life?

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Keep your Leaf in 76F air conditioned garage at around 35% SOC. That would be great for battery longevity. To make the battery last even longer I would park it overnight in a freezer.

But seriously, in your case I would set a timer to start charging 2.5 hours before first departure of the day and end the day with 30% state of charge, plug in and repeat the process. Charging for 2.5 hours on L1 should put you at 45% state of charge and provide 10 miles of range until 30%.

Antronx... You really are precise!!

In high school, were you a Chemistry major and an expert with measuring with a "graduated cylinder"?

Just teasing.. great prescription for this driver..

peace..

AntronX said:

Keep your Leaf in 76F air conditioned garage at around 35% SOC. That would be great for battery longevity. To make the battery last even longer I would park it overnight in a freezer.

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Good idea: I'll air condition our Las Vegas garage. That should only cost two or three times the price of replacing the Leaf's battery pack!

But I'll be much more comfortable while I'm in there doing all the maintenance work the Leaf needs.

Hey, wait a minute!

powersurge said:

In high school, were you a Chemistry major and an expert with measuring with a "graduated cylinder"?

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Guilty as charged

commasense said:

Good idea: I'll air condition our Las Vegas garage. That should only cost two or three times the price of replacing the Leaf's battery pack!

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It would cost less than $100 in electricity per summer if you divert some of central AC air to the floor of the garage. I would insulate the garage door to reduce heat loss and air leaks. But really, if you only need this car do provide 10 - 20 miles per day, the battery should last you over 10 years as is. Just avoid charging it above 3.9 volts per cell or above 50% state of charge and it should last longer. Leafspy would help keeping watch on battery voltage. Look into installing 30A 240V L2 charger, at it would greatly improve usability of the car. A 30 minute charge on 6.6kW would give you 11 miles of added range, great for unexpected trips while keeping the Leaf at low stage of charge.

Hi there,

is it okay to use the Ignition ON while charging Nissan Leaf, for longer times.

Or it is a safety or fire concern?

Or it will degrade battery?

with Thanks
NOLTH

Hey Everyone, about a week ago I took delivery of our first EV. A 2013 S. Instead of starting a new thread I thought I would bump this up to see if there was any new information regarding this topic. I will have roughly a 10 mile or less round trip daily commute. What I have been doing every night is just plugging in to 110 and let it turn off at 80%. Every morning this has me at around 72 miles or so on the guessing MPG-E gauge.

Just like everyone else the goal is the longevity of the battery. My OBD II adapter arrives today so I can see exactly what Leaf Spy Pro says. The car shows 11 out of 12 bars still. I hope to drive this a few years then let it be my daughters first car. In our small town driving to work/school makes about a 7-9 mile round trip.

The convenience of nightly plugging in and letting it shut off at 80% works out well. I just wanted to get feedback if this was actually hurting anything.

Thank you for the feedback.

commasense said:

Although your experiences and opinions are welcome, I'd prefer authoritative sources of scientific/empirical data, if possible.

Thanks.

Click to expand...

As a 2013 owner myself, set it for 80% mode and call it one and done. I did not baby my 2013 and you see from my leaf spy history in my signature that it still performed great despite the massive degrading and abuse I did to it.

KenpoLeaf said:

I will have roughly a 10 mile or less round trip daily commute. What I have been doing every night is just plugging in to 110 and let it turn off at 80%. Every morning this has me at around 72 miles or so on the guessing MPG-E gauge.

Just like everyone else the goal is the longevity of the battery. My OBD II adapter arrives today so I can see exactly what Leaf Spy Pro says. The car shows 11 out of 12 bars still. I hope to drive this a few years then let it be my daughters first car. In our small town driving to work/school makes about a 7-9 mile round trip.

The convenience of nightly plugging in and letting it shut off at 80% works out well. I just wanted to get feedback if this was actually hurting anything.

Thank you for the feedback.

Click to expand...

Car is 10 years old, and has lost 15% to 20% with 11 capacity bars showing.

Loss isn't linear, close enough for a guess, in another 10 years you would be down 30% to 40%. The car would still be usable. Maybe in 20 years from now the resistance would increase to the point where acceleration, hill climbing and such would be impaired enough to make the car unsafe to drive. That will likely happen before the range gets too short to do the 10 mile round trip to work/school.

I truly doubt if you or your daughter will care in 20 years.

You might be able to do somewhat better, but would be a bother. Lowering the average SOC from 70% to 50% would reduce calendar capacity loss and might give you another 5 to 10 years. But that would require a charge to stop at 60%, which isn't easy.