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Newbie question: 80% overnight vs morning?

Posted: Mon Apr 09, 2018 2:06 pm
by Honva
Just got a 2018 Leaf as my first EV. I have read opinion that it is better for batteries not to stay at full charge for too long. How about at 80% charge? Does it matter if everyday I charge the battery to 80% in the evening and drive the next morning? Would it be better to charge to 80% in the early morning instead? My gut feeling is probably no difference at all. Want to hear from other experienced users. Re-charge the car in the evening is more peace of mind to avoid any surprises from overnight or early morning power outage :?

Thanks in advance for any input.

Re: Newbie question: 80% overnight vs morning?

Posted: Mon Apr 09, 2018 3:40 pm
by LeftieBiker
Recharging to whatever level you need, with the charge ending soon before you leave for work, is best. If you can charge to 80% overnight, that's great. I just hope that you realize you will have to limit the charge yourself, either by unplugging it or by have it reach 80% in the morning. The newer Leafs don't have a charge to 80% feature.

Re: Newbie question: 80% overnight vs morning?

Posted: Mon Apr 09, 2018 6:35 pm
by WetEV
Honva wrote:Would it be better to charge to 80% in the early morning instead? My gut feeling is probably no difference at all. Want to hear from other experienced users. Re-charge the car in the evening is more peace of mind to avoid any surprises from overnight or early morning power outage :?


Several different points of view. From the point of view of the utility company, they would rather you charged in the night, 12AM to 4AM. That is when the grid has excess capacity, as demand is at minimum. Or in places with lots of solar, perhaps midday. Depends on the local power grid sources and loads. Evening is probably one or the worst, or the possible worst time, from a grid point of view.

From the point of view of maximizing battery life, charging right before departure, and perhaps to 100% one day a week, would be ideal. The utility company might not like that, as there is often a morning power use peak.

I don't know your power outage situtation. Or alternatives, like charging at work in the case of a power outage. So I'm not going to guess. I don't get power outages very often. When I couldn't charge at home, I charged at work.

Re: Newbie question: 80% overnight vs morning?

Posted: Mon Apr 09, 2018 7:19 pm
by Honva
Thanks for the replies.

Yes, I know that the 18 Leaf don't have the 80% option. However, this is my drive to work car which is quite consistent that I only use about 35-40% of power everyday. I just set the timer for 130 min and it will get back to about 80%. When needed, I just change the timer slightly after stopping. The 80% option is not really necessary.

My bad. When I said evening, I actually mean around 11pm. :) A time when demand is low. If it is not good to the battery, I could do 4:50-7:00 instead. Car is in garage which won't be too hot or too cold. If there are no significant difference, I would prefer to charge around 11:00 instead.

Re: Newbie question: 80% overnight vs morning?

Posted: Mon Apr 09, 2018 9:24 pm
by LeftieBiker
My bad. When I said evening, I actually mean around 11pm. :) A time when demand is low. If it is not good to the battery, I could do 4:50-7:00 instead. Car is in garage which won't be too hot or too cold. If there are no significant difference, I would prefer to charge around 11:00 instead.


We generally say that if you charge to 80% it doesn't matter if the car sits afterward. However, given the looming possibility that the 40wkh pack will have serious problems with heat, I'd say that in hot weather you should let the car cool for as long as possible. That means having it reach 80% right before you leave for work. It may also mean only charging every other day, to let the pack cool as much as possible.

Re: Newbie question: 80% overnight vs morning?

Posted: Mon Apr 09, 2018 10:09 pm
by alozzy
The OP is from Ontario, Canada. Long before Ontario summer arrives, there should be plenty of feedback from owners in hotter climates about battery temps, accelerated degredation, etc. If it was me, I wouldn't worry too much about charging to 80% ish at anytime (whenever convenient), nor about having the pack sit idle at that SOC. The jury will be out by June/July...

Re: Newbie question: 80% overnight vs morning?

Posted: Mon Apr 09, 2018 10:37 pm
by LeftieBiker
alozzy wrote:The OP is from Ontario, Canada. Long before Ontario summer arrives, there should be plenty of feedback from owners in hotter climates about battery temps, accelerated degredation, etc. If it was me, I wouldn't worry too much about charging to 80% ish at anytime (whenever convenient), nor about having the pack sit idle at that SOC. The jury will be out by June/July...


The climate in much of Ontario isn't a lot different from mine, so I'd expect some 90F days and some stretches of 80+ days and warm nights. It wouldn't take any more than that to degrade a heat-intolerant battery. As I wrote, they only need to worry in hot weather.

Re: Newbie question: 80% overnight vs morning?

Posted: Mon May 07, 2018 6:05 am
by jusgetalong
Elec car newbie here with a question on charging. We live in Fla., really hot here, but, the car is always in a garage. It is charged using an L2 charger in the same garage. We can charge anytime we want or as long or as short as we want. Guess thats what come when you retire ;) . Based on this should I charge the battery multiple short charges to reach my 80% or just one long charge to 80%. Also should I let the battery run down to 20% before charging or just top it off to *)% each time we run down some. And balancing? Can it be done on the L2 and what process to use? Great blog you guys have. :)
I ask this in reference to stretching out battery lifespan.

Re: Newbie question: 80% overnight vs morning?

Posted: Mon May 07, 2018 11:58 am
by LeftieBiker
Balancing should occur with any charging level, but only happens at 100% charge, so plan on a full charge once a month, right before you leave for a drive. You're be best trying to keep the car roughly between 25% and 75%, and planning on charging only when the pack is cool. This sounds nuts, but thanks to Nissan's "engineering" I'm planning on putting an air conditioner in my garage so I can store the car in moderate temps during heatwaves. I'll set it for about 78-80F...

Re: Newbie question: 80% overnight vs morning?

Posted: Wed May 23, 2018 6:22 pm
by GaryHere
LeftieBiker wrote:Balancing should occur with any charging level, but only happens at 100% charge, so plan on a full charge once a month, right before you leave for a drive. You're be best trying to keep the car roughly between 25% and 75%, and planning on charging only when the pack is cool. This sounds nuts, but thanks to Nissan's "engineering" I'm planning on putting an air conditioner in my garage so I can store the car in moderate temps during heatwaves. I'll set it for about 78-80F...


I had this crazy idea today to bring my 15 Leaf to a car wash that I know has very cold water and use the undercarriage wash a few times to see if it would budge my constant 6 bar battery at all.

NO. Nothing.

I think you guys mentioned to me on my other thread that it takes some time for that large mass to get affected by any temp change.

How long do you think it would take in your future AC garage setup? Or is it something preventative?

Just curious.

Thanks

G