Differences between charging 80% and 100%

[carolle]

I'm new to LEAF. I just started to use LEAF last week for 2-year lease. My usage styles are:
- Typical commute is just 15 miles/day.
- On the weekend, it could be 40-50 miles. I'm trying to use as much as I can
- Using only 120V charging. (Rented house )
- Living in Northern CA. (No snow)

My dealership simply tells me that charging 100% is good for me, because I'm leasing it. But, I'm wondering in terms of "charging electric cost".

It seems that charging from 80% to 100% takes more time than charging to 80%. Is this correct?

If so, it implies more energy is required to fully charge, which in turn means more electric cost. I'm wondering my understanding is correct or not.

If there is no difference between charging 80% and 100%, I'd love to charge 100% so that I can always LEAF whenever possible.

 

[bowthom]

Hello,
The reason it takes more time to charge from 80% to 100% is because the onboard charger is reducing the charging rate as the batteries "top up." There is no additional cost per kWh, it's just that it takes longer to put the energy in.

BUT.......time is money

So if the time is costing you then that's a different matter.

Don

P.S. They are implying that any battery degradation caused by charging to 100% is not your concern because of the short lease term. Personally I'm an 80%ter because I want my battery to last. I own my Leaf.

 

[Stoaty]

It is generally better to charge to 80% unless you need 100% to make your destination. No problems from charging to 100% when needed, provided you don't leave the Leaf at 100% for more than a couple of hours. Otherwise, leaving Leaf fully charged is not good for the battery pack and will hasten loss of capacity. See also the Wiki for detailed information on battery capacity loss (or what we think we know, anyway):

http://www.mynissanleaf.com/wiki/index.php?title=Battery_Capacity_Loss" onclick="window.open(this.href);return false;

 

[ebill3]

It seems that charging from 80% to 100% takes more time than charging to 80%. Is this correct?

If so, it implies more energy is required to fully charge, which in turn means more electric cost. I'm wondering my understanding is correct or not.

If there is no difference between charging 80% and 100%, I'd love to charge 100% so that I can always LEAF whenever possible.

Hurray for your new LEAF.

First off, you always take more power from the wall than you get back out of the battery.

Yes, going from 80% to 100% does take longer than going from 60% to 80%, because that is the way Li cells are charged - near charge termination, voltage is held constant and current tapers off. So, yes, due to inefficiencies, pumps running and such, the long term charging costs will be a bit more, but I doubt that it would be enough to offset your delight in always having a fully charged car.

 

[RegGuheert]

It seems that charging from 80% to 100% takes more time than charging to 80%. Is this correct?

Yes.

If so, it implies more energy is required to fully charge, which in turn means more electric cost. I'm wondering my understanding is correct or not.

Yes, there is a little bit more electricity used to charge to 100% because the battery management system switches in resistors to balance the cells in the pack. I don't think it is enough to be concerned with.

If there is no difference between charging 80% and 100%, I'd love to charge 100% so that I can always LEAF whenever possible.

As mentioned, it will cause more battery degradation if you leave it charge to 100% all the time. Perhaps you can charge to 80% Monday through Friday and 100% on the weekends. (But if you have an S, I'm not sure if you have that option.)

 

[RegGuheert]

The reason it takes more time to charge from 80% to 100% is because the onboard charger is reducing the charging rate as the batteries "top up."

I've never seen the charge taper on 120V. I've seen it at full power just a couple of minutes before it stops on multiple occasions.

 

[RonDawg]

There is no additional cost per kWh, it's just that it takes longer to put the energy in.

From what I've read here before, there is a bit more waste in charging on 120 volt than on 240 volt.

 

[LEAFfan]

I'm new to LEAF. I just started to use LEAF last week for 2-year lease. My usage styles are:
- Typical commute is just 15 miles/day.
- On the weekend, it could be 40-50 miles. I'm trying to use as much as I can
- Using only 120V charging. (Rented house )
- Living in Northern CA. (No snow)

My dealership simply tells me that charging 100% is good for me, because I'm leasing it. But, I'm wondering in terms of "charging electric cost".

It seems that charging from 80% to 100% takes more time than charging to 80%. Is this correct?

If so, it implies more energy is required to fully charge, which in turn means more electric cost. I'm wondering my understanding is correct or not.

If there is no difference between charging 80% and 100%, I'd love to charge 100% so that I can always LEAF whenever possible.

Carolie, here is my advice if you need or want 100%...charge to 98% instead. It doesn't take long after 80%, you will have regen braking, and there's really an unnoticeable difference between 98% and 100%.

 

[carolle]

Thank you so much for your quick and very detailed replies!

I understand much better now. My car is SV + QC option.

 

[EatsShootsandLeafs]

Yes, there is a little bit more electricity used to charge to 100% because the battery management system switches in resistors to balance the cells in the pack. I don't think it is enough to be concerned with.

Also the charging cooling system or whatever it is will continue to run...

I am leasing my Leaf with almost no intention of buying it out (but I will lease another). I still do 80% most days because it's better for the battery and I'd rather the next owner benefit from that, whoever he may be.

 

[Reddy]

Lots of info on L1 (120 V or trickle) charging here: http://www.mynissanleaf.com/viewtopic.php?f=34&t=10776&p=247635#p247635

You are perfect for just trickle charging. Don't worry about "efficiency", costs, whether to use L2 (240 V) charging, etc. With short commutes, it's not worth the worry. Also, don't worry about whether the battery is completely full (100%), partially full (80%), or even less than half full (at least during the weekday). With such a short commute and a lease, you can keep the battery just about any state of charge and it won't matter. If you are buying and want to treat the battery nice, then that's a different story (see Stoaty's guide: http://www.mynissanleaf.com/viewtopic.php?f=27&t=5508&hilit=efficiency. I've got an 8 mi RT commute and once made it there and back (35 mph city streets) on the last battery bar (or low battery warning LBW) just because I had an unexpected weekend project.

For optimum use, I would set your timers to charge from about 1-5am to 80% on the weekdays, and then from 12-8am (or so) to 100% on the weekends. You get "about" 4-5 mi of travel range for every hour of charging. Charging 4 hrs should replace your day's travel distance (15-20 mi), getting you back up to 80%. If you expect to travel 50 mi on Sat & Sun, you need "about" 10-12 hr of charging the night before. Adjust your timer for your expected needs. FYI, you'll need more time during the winter and less during the summer.

If plans change, or you need to drive more/less on a particular day, you can always push the override button and start charging immediately. A couple of warnings here: (1) you'll probably drive more because it's so enjoyable compared to a gasser. (2) Long trips or back-to-back drives longer than 50 mi need some extra planning and you may need to start charging to 100% a day or two in advance just in case (it takes 20 hrs to fully charge from empty).

 

[carolle]

Reddy, really thank you for your very detailed reply!

Yes, I'm using 80% for week days and 100% for the weekend. And, one good thing is that there are DC fast chargers (by Blink) just near by my office and my home! It was very good (very quick to 80%, though a bit longer time to 100%) and free for now!

 

[DougWantsALeaf]

Though the 2013 has only been out for 3 months, has anyone been able to validate that charging to 80% is maintaining their GIDS better?

IS there anyway I can see the GIDS without purchasing a special meter and hacking into the electrical?

 

[planet4ever]

IS there anyway I can see the GIDS without purchasing a special meter and hacking into the electrical?

Yes, you will have to buy a meter. $190 for Gary Giddings kit, or $300 fully assembled. (GIDs are named in honor of Gary.) Here is his web page: http://www.wwwsite.com/puzzles/socmeter/

But forget about hacking into the car. The meter just plugs into the OBDII port under the dash. That's the standard port that every modern car is required to provide. There are some other after-market OBD meters which can access the same information.

Ray

 

[TomT]

It will be no different than it is for the 2011 and 2012...

Though the 2013 has only been out for 3 months, has anyone been able to validate that charging to 80% is maintaining their GIDS better?