Should I charge to 80% daily?

[djjazzy]

So I'm reading set charge to 80% vs 100% to extend battery capacity life. Would it be better to charge every day to 80% vs going all the way to 100%? If I charge to 100%, I can make 2 RT's to work with out charging. So that is an every other day charge. If I only charge to 80%, I'll need to hit the charger every day at work for 8 hrs or less to get it to 80% at 120V. What will be best for my batteries, I want to keep the car as long as possible. Purchased, not leased.

 

[surfingslovak]

So I'm reading set charge to 80% vs 100% to extend battery capacity life. Would it be better to charge every day to 80% vs going all the way to 100%? If I charge to 100%, I can make 2 RT's to work with out charging. So that is an every other day charge. If I only charge to 80%, I'll need to hit the charger every day at work for 8 hrs or less to get it to 80% at 120V. What will be best for my batteries, I want to keep the car as long as possible. Purchased, not leased.

Welcome! Where do you live approximately and where is the car parked during the day? While the 80% charging recommendation is sound, many found from experience that the ZIP code and covered parking can have as much, if not more impact on battery life. That said, I would not be concerned to charge to 100%, if you don't let it sit fully charged for a long time. Since your commute is fairly short, and the battery probably does not discharge very much on the way there, I would advise against leaving the car nearly fully charged all day, and possibly exposed to the sun. If it means that you would limit the charge to 80% on most days, then that could be advantageous.

 

[LeftieBiker]

If you can charge every day to 80%, that's probably better - especially if two round trips will bring it below 20%.

 

[djjazzy]

I live in SF and commute daily to San Bruno, 14 OW or 28RT, plus some stops on the way home. I figure 30 miles average daily. Now I can charge for 8.5 hours at work on 1200V. On days that I'm at work longer, I can sometimes get the car to 98%. The car is outside in the sun while being charged, but day time temps rarely ever get over 80 degrees during the summer. If some how get charged to nearly 100 percent, I'd drive home and should use 15-20% depending on route and traffic. Using this senario, I don't need to charge at home, and return to work the next day, and the battery level is about 65%. I still don't charge, and complete another RT back to home and work the next day, and battery level is then at 25-28%. I'll charge as long as I can, sometimes reaching 70-80%. But if I stay at work longer, I can get it to almost 100%.

So should I charge daily to 80% at work, or charge to 100% whenever I can, so I can skip a charge day. I may try to see if an 80% charge at work will get me 2 RT's back to work, without having to charge at home.

 

[djjazzy]

I live in SF and commute daily to San Bruno, 14 OW or 28RT, plus some stops on the way home. I figure 30 miles average daily. I can charge for 8.5 hours at work on 120V. On days that I'm at work longer, I can sometimes get the car to 98%. The car is outside in the sun while being charged, but day time temps rarely ever get over 80 degrees during the summer. If some how get charged to nearly 100 percent, I'd drive home and should use 15-20% depending on route and traffic. Using this senario, I don't need to charge at home, and return to work the next day, and the battery level is about 65%. I still don't charge, and complete another RT back to home and work the next day, and battery level is then down to 25-28%. I'll charge as long as I can, sometimes reaching 70-80%. But if I stay at work longer, I can get it to almost 100%.

So should I charge daily at work to 80%, or charge to 100% whenever I can, so I can skip a charge day. I may try to see if an 80% charge at work will get me 2 RT's back to work, without having to charge at home. Just trying to avoid charging at home since work is supplying the 120V. :lol:

 

[Stoaty]

So should I charge daily to 80% at work, or charge to 100% whenever I can, so I can skip a charge day. I may try to see if an 80% charge at work will get me 2 RT's back to work, without having to charge at home.

Charge daily to 80% at work. Lower depth of discharge (DOD) is better for the battery. How much difference it will make, no one knows. See also:

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

 

[mwalsh]

Use the 120v at work, but avoid the 1200v. :shock:

 

[Valdemar]

If you leased just charge to 100% and don't worry about a thing. In any case, if you leave work shortly before or after the car reaches 100% you'll be fine. It is letting the car sit at high SOC % for prolonged periods of time that causes accelerated degradation, even more so at high ambient temperatures.

 

[johnrhansen]

let's see... It looks like you use 30-40% charge daily, and when you charge at work, you ought to get about a 50% gain. If It was me, I'd only charge to 80 percent, and only plug in when the charge gets below 40. (either at home or at work) Whether you lease or not, I think it's a good idea to try to preserve the battery as best you can, after all there was an environmental cost incurred in producing the battery, and in producing it's replacement when the time comes. I've heard the battery should not sit long above 80 percent, or even better 60 percent.

 

[pkulak]

Whether you lease or not, I think it's a good idea to try to preserve the battery as best you can, after all there was an environmental cost incurred in producing the battery, and in producing it's replacement when the time comes.

Plus, you never know if you'll want to buy at the end of your lease. If you trash the battery, you'll pretty much have no choice.

 

[ebill3]

Leased or owned, I would charge to 80% at work every work day, and 80% at home on non-work days.

EDIT: No, I'm not a policeman, but it isn't considered nice to have two threads running with the same question or discussion.

http://www.mynissanleaf.com/viewtopic.php?f=4&t=14481

 

[surfingslovak]

Charge daily to 80% at work. Lower depth of discharge (DOD) is better for the battery. How much difference it will make, no one knows.

Yes, agreed. Also, consider yourself lucky that both your residence and place of employment are in a relatively cool and breezy part of the Bay Area, which get fair amount of fog in the summer. This reduces solar loading and helps keep the pack cool most of the time.

 

[djjazzy]

Attn moderators, sorry for the double post , you can close out this thread.

For all others who want to view or chime in go here:

http://www.mynissanleaf.com/viewtopic.php?f=27&t=14491

 

[surfingslovak]

EDIT: No, I'm not a policeman, but it isn't considered nice to have two threads running with the same question or discussion.

Thank you, Mr. Thread Police. Now the OP wants to have the other discussion shut down. I wrote a fair bit in response to his question there, and I'm not sure how I should feel about that thread being thrown out. I guess the advice we give on this forum is worth what we charge for it. Nothing? :shock:

 

[djjazzy]

Thanks for all the suggestions, just trying to find out what would be the best long range plan for my everyday commute. I purchased the Leaf, so I'd want it to have good capacity beyond 3 years for sure.
Sounds like charging to 80% is a step in the right direction. What's the rule of thumb regarding charging to 100%?
I'm hearing, " don't let it stay long at 100%" does that really mean, after the car reaches 100%, it's not recommended to let it sit for days at 100%, especially in hot temperatures. Or is it, "don't let it sit for more than a few hours in hot temperatures".

If I do charge to nearly 100% on long days at work, I'd be driving it home that evening and it would be down to about 80% when I reach home. Then going back to work in the am should bring me to 60-65%. Would most of you recharge to 80% at work? or skip the charge, and run the Leaf back home, and back to work the next day, ( level should be about 25% ) then charge it up close to 80%.

Looks like RTs home to work are running about 35% of battery usage.

 

[RonDawg]

Even if a 100% charge will let you skip a charging day, I would not recommend doing so. Especially since you will be charging at work primarily, you never know if the outlet at work suddenly stops working, or becomes blocked in, or some jerk unplugs you early in the workday, and now you may not have enough juice to get home because you failed to charge the previous day.

I would say charge everyday to 80%. If the above scenario happens, you can still charge at home. Another benefit is that by not charging to 100%, you will have regen braking available to you at all times which helps prolong the life of your friction brakes.

 

[surfingslovak]

As mentioned in the other thread, which you decided to shut down, I think given your commute you should charge to 80%.

That said, please don't expect 80% charging to be hugely beneficial. It will help, but we don't know how much. There was a case of someone leaving their LEAF sitting at 100% for a month in Phoenix last year. Although she was one of the first to report the loss of a capacity bar, others followed soon thereafter. There were religious 80% chargers in the group that followed, and this particular battery care practice did not seem make all that much difference for them.

Even if someone pointed out that Phoenix was a special case, which it likely was, the LEAF owner community has collectively not been able to determine just how much 80% charging helps extend battery life in the field. While this is a good and sound recommendation, please don't get your hopes up, and assume that this might help add two or three years to your battery life, because it won't. While it's a good practice, it won't have that much effect. In terms of your other question, here is what Stoaty wrote on the wiki. I would recommend reading his battery capacity article there in its entirety, if you can:

Technically, lithium battery calendar life is a function of 4 variables:

Mean temperature
Standard deviation of temperature
Mean state of charge (SOC)
Standard deviation of SOC

Also, the following battery care practices Dan Myggen wrote for Tesla Roadster owners might be of interest. This was the starting point for several of us.

Tesla Roadster Battery Care

 

[planet4ever]

The only downside to charging at work every day is the trouble of getting the cable out and plugging it in, unplugging it and putting it back in the car. If you are worried about the number of cycles, don't be. The battery experts tell us that a cycle is all the way down and all the way back up. If you charge from 30% to 80% that's half a cycle.

Personally, I'm a creature of habit. Anything I don't do every day is something I'm likely to forget when I really need it. If you're using 35-40% per day, I'd say charge every day to 80%. If you were using only 20-25% per day, then charging to 80% every other day would make sense, because it would keep the battery closer to half full. As for charging to 100%, I do that only when I need to to get to the next point where I will be staying long enough for charging to be reasonable.

Ray

 

[DaveEV]

MOD NOTE: Duplicate threads merged.

 

[ebill3]

EDIT: No, I'm not a policeman, but it isn't considered nice to have two threads running with the same question or discussion.

Thank you, Mr. Thread Police. Now the OP wants to have the other discussion shut down. I wrote a fair bit in response to his question there, and I'm not sure how I should feel about that thread being thrown out. I guess the advice we give on this forum is worth what we charge for it. Nothing? :shock:

Well, shucks, sorry I rained on your parade, but it looks like the mod has taken care of it.
Peace.