Which is better: 80% charge daily vs 100% once weekly?

[ccoleby]

I have a new 2013 SL. Like it alot. My daily commute is 10-15 miles per day. I could get by with charging only once weekly if I do 100%. Is it better to just charge or top of my leaf daily at 80% vs letting it drop down to say 20% charge and then fully charge it just once per week to 100%?

I would think only charging 60 times per year would be better for the battery life then daily charges.

Am I right?

 

[nosuchthing]

I would charge 100% and use it up over the few days and then charge again 100% when I hit low batt warning (7-8 miles).

 

[TimLee]

What is better is letting the charge drop to around 40% and then charge back to 80%.
Charging twice a week to 80% is far better for the battery than charging once a week to 100%.
The worst thing for the battery is spending much time above 80%, or spending much time below 20%.
Staying in the 30% to 70% range is probably optimal, although Nissan hasn't shared enough detailed information on the battery and its testing to be totally certain of this.

 

[braineo]

just free range it and don't worry about it as if this car is the last one you will ever buy. If the range and the battery doesn't work for you, better to find out early and have it covered by either warranty or a class action lawsuit.

 

[ccoleby]

I've been timing it so that 100% is reached within an hour of me leaving for the day. It doesn't spend much time above 90%.

I did a test drive with another leaf from the dealership going up and down a canyon in 20-30 degree weather, making it about 78 miles round trip. It helped me get a feeling for what it could achieve and decreased my range anxiety some.

Perhaps I'll start recharging it when it hits 1/3 battery capacity.

 

[GregH]

Set the timer so it finishes 100% around the time you leave for work and plug it in every few days when the SOC drops below 30% or whatever you're comfortable with. The main thing is that you don't spend too much time at high SOCs... and park in the shade..

 

[kovalb]

Set the timer so it finishes 100% around the time you leave for work and plug it in every few days when the SOC drops below 30% or whatever you're comfortable with. The main thing is that you don't spend too much time at high SOCs... and park in the shade..

+1
Two key points.
1) It is the time at charge and temperature that affects battery life. The best condition possible is letting the battery rest at 50% SOC in cool weather.
2) Charging the battery to 100% is good. Cell balancing only occurs over 80% SOC. Cell balancing ensures the battery can hold the maximum energy possible by trickle charging each cell up to its limit.
Therefore GregH's advice is good! The battery temperature is an even greater factor so parking in the shade or garage is very helpful. The temperature of the ground can get very much hotter than the air and it then radiates to the battery. The greenhouse also raises cabin temperature which is the other source of heat to the battery when parked.

 

[planet4ever]

As others have said, the best battery life can probably be gotten by staying between 20% and 80%. If you know you aren't going to drive more than 15 miles the next day, let it drop to 4 bars before charging to 80% and you will meet that criterion. (Unless they have remapped the bars for 2013, 20% is a bit past when it drops to 1 bar.) Do charge it to 100% at least once a month for better cell balancing.

Note: The battery experts here tell us it isn't just the number of times you charge the battery but also how deep the charges are. A 'cycle' is a full charge and full discharge, not just up a ways and down a ways. The (perhaps incorrect) conclusion I have drawn is that life is somewhat affected by the sum total kWh you pour into the battery, whether you do that with fewer larger charges or more frequent smaller charges.

This is not to say that is the only factor, or even the most important factor, affecting life. Yes, time at 100% is important, and temperature while at 100% may be even more important. It is likely that time at very low charge levels is also important.

Ray

 

[DanCar]

What is better is letting the charge drop to around 40% and then charge back to 80%.
Charging twice a week to 80% is far better for the battery than charging once a week to 100%.
The worst thing for the battery is spending much time above 80%, or spending much time below 20%.
Staying in the 30% to 70% range is probably optimal, although Nissan hasn't shared enough detailed information on the battery and its testing to be totally certain of this.

+1
Also it matters where you live and speed of your drive. If you drive at 85 mph and or its hot, then it matters more. Charging to 100% is a known issue, so keep it below that if easy to do. Not mentioned as much, but leaving it near 0% will degrade the battery also.

 

[DaveEV]

What about option 3?

Manually time the charge daily so you use the middle of the pack. 10-15 miles daily - charge up to 7-8 bars every day then drive it down to 4-5 bars. With a '13 SL and 30A charger, this should only take about 30 minutes of charging every day. Maybe set a timer to charge 30min/day right before you leave and manually tweak as necessary.

That will keep the SOC in the sweet spot for storage (ideal storage SOC is generally regarded to be around 40-50%) and give you nice shallow partial cycles which is great for cycle life.

 

[Herm]

+10

what drees said

 

[surfingslovak]

+10

what drees said

Yup. If the OP is will to entertain that, this regimen will result in lower average SOC and shallow cycles. Both should be good for battery longevity. That said, ambient temperature could be an even larger contributing factor than cycling, at least early in the life of the vehicle. Keeping the pack cool, and picking covered or shaded parking spots might be a good idea as well.

 

[thankyouOB]

use the timer to charge over night to 10 bars, with the charger turning off a few hours before you leave.
an hour before u depart, start the charge to 100%

 

[TimLee]

Manually time the charge daily so you use the middle of the pack. 10-15 miles daily - charge up to 7-8 bars every day then drive it down to 4-5 bars. With a '13 SL and 30A charger, this should only take about 30 minutes of charging every day. Maybe set a timer to charge 30min/day right before you leave and manually tweak as necessary.

That will keep the SOC in the sweet spot for storage (ideal storage SOC is generally regarded to be around 40-50%) and give you nice shallow partial cycles which is great for cycle life.

+10
If the OP is willing to do this, that would be the optimal approach for extending battery life.

 

[bruce27513]

How do you know where you will need to go at lunch, after work?
Charge the car to 100% as often as you can.
I have 11,000 miles on a 2012 Leaf and charge every chance I get to 100% if I have the time.
What if you have to hurry to work or home 0r an errand, and need to use the highway.
Please don't give ICE drivers an excuse to be able to say, " I know a Leaf driver that could not go somewhere because he did not have enough range".

Please charge to 100%. That way you have the most range possible everytime you leave.

 

[DaveinOlyWA]

Neither is what i choose.
Where do u live?
Do u have shade to park at work?
Driving as soon as the charge is complete could add to heat issues.

If i were u, i would charge to 80% daily. This gives u the range for any unexpected trips AND for trips u generate...the LEAF is that much fun to drive

 

[Reddy]

I missed the OP's location. Hot? Cold? Search my name and you will see that I typically charge a couple of hours each night to keep the battery between 4-8 bars. If I were you, I would set your 80% timer to charge 3 - 4 hrs on L1 each night from 1-5am. If you use L2, then 1-1.5 hr should be sufficient. Set your CC timer for whenever you leave. Then plug in every night and get your charge (essentially the distance you consumed for the previous day's commute). If you drive more on the weekends, then adjust the second timer for more hours. When you need more, hit the override button. Thus you are grid-friendly most of the time, the battery stays in the mid-range most of the time, and you can always override to fully charge as needed. This is best for the battery. I fully charge only when I know I will be heading out of my small town, and don't leave it there very long since I'm driving immediately. More info:
http://www.mynissanleaf.com/wiki/in..._Loss#Factors_Affecting_Battery_Capacity_Loss
http://www.mynissanleaf.com/viewtopic.php?f=27&t=5508

 

[evnow]

I have a new 2013 SL. Like it alot. My daily commute is 10-15 miles per day. I could get by with charging only once weekly if I do 100%. Is it better to just charge or top of my leaf daily at 80% vs letting it drop down to say 20% charge and then fully charge it just once per week to 100%?

Are you sure you will not drive the Leaf again in the evening ? How about weekends ?

I've a similar commute - I charge every day to 80%. On days I plan to drive a lot, I charge to 100%.

My experience is that you would want to take Leaf everywhere you go, as much as possible. So, you don't want to have just 20 or 30% in the morning on any day. Better to charge to 80% daily.

BTW, did you buy ? I suggest leasing to anyone really worried about battery.

 

[BiosDude]

I've had my Leaf for a week. Leased it for 2 years on Easter Sunday. My commute is 41 miles round trip to/from work. My nearest QuickCharger to home is a 10 mile round trip (I need to find one on the way to/from work) making it about 52 miles for a commute. Since I don't know what my day is going to be, I swing by on the way home and set the charger to 90% and go get stuff for dinner inside the store. I come out and head out when it gets between 80-90%. Repeat daily. I don't own a lv2 home charger (don't plan on buying one) and have never used the lv1 charger after making sure it worked on day 1. Total cost to drive my almost 500 miles I've put on so far? $0.00. Just gotta love those free QuickChargers!

To get back to the OPs question, LifePO4 batteries don't "like" either extreme of 100% or 0%. At 100%, they can swell, heat up, leak, burst into flames, and other fun stuff. At 0% they can reverse polarity and fry your whole pack. As somebody else mentioned, rechargeable battery life is measured in "cycles". To test this, they charge the battery up to 99% and discharge it down to 1%. Repeat. Remember that "life" is an average of the tested group minus a percentage of margin. So user A may get a zillion cycles while user B gets only a jillion. My guess is that Nissan has set their chargers to max out at about 98% of true 100% battery capacity and to shut down the car around 2% to prevent users from trashing their packs and creating warranty calls. I'm also assuming that the battery manufacturer has an added margin built into their specs. There are a small portion of end-users that are extreme idiots, hence all of the amusing warning labels on everything. To further support this, I was offered a "battery degradation warranty" when I leased (I pointed out that the pack was covered for the term of the lease under the normal warranty and declined.) Nissan would not offer this unless they had set in place some safeguards on their packs. As such, I intend to charge my Leaf daily to 80-90% at a QuickCharger, take it in for the 7,500 mile check-ups (which I understand includes a pack balancing charge and is included in my lease), and enjoy the surprised look on the BMW owners when I floor it. I also base this assumption on what I know the computer industry has done for years on laptop batteries and their charging cycle.

 

[DaveinOlyWA]

My guess is that Nissan has set their chargers to max out at about 98% of true 100% battery capacity and to shut down the car around 2% to prevent users from trashing their packs and creating warranty calls.

actually 93.6%