Eight Tips to Extend Battery Life of Your Electric Car

[thankyouOB]

so, now I have two issues and questions for my friends here:
--i can use trickle or L2 at work. does it matter for battery health. I park for 8 hours and either mode will get me to 80% for the trip home.
I can use L2 and not charge at home but that would run my battery down to 2 bars when I get to work.
--i have always used the start and end times, so I charge beginning when I plug in, and charge the vast majority of times to 80%.
would battery life be extended if I begin to use just the end timer, so I dont hold the battery at 80% for several hours on work days?

thanks for any comments.

 

[LEAFfan]

I would use the 120V/trickle so it will free up the L2s for others that may need to use those. Leaving the car at 80% for the day is good. Even leaving it at 100% for a few hours isn't going to hurt either.

_________________
OCT Wall to Wheels (according to the Blink): 5.6m/kW h
LEAF Dash: 6.4m/kW h w/o HVAC
Lifetime Platinum Driver
#1 Average Energy Economy (m/kW h) for Oct. in the Region and the U.S.
4.8 kW DC PVs ($ .91/W fully installed)/ Dec., 2010

 

[thankyouOB]

there are a dozen blinks and I am the only Leaf or Volt, at the moment.

 

[gbarry42]

Our battery experts have pointed out before that charging a 24kWh battery at a 2.8 kW rate is very close to a 10% rate. Anything less than this is considered a trickle charge. Choosing between L1 or L2 has no effect on the battery at these low levels.

 

[KJD]

there are a dozen blinks and I am the only Leaf or Volt, at the moment.

In that case I would use the level 2 and not worry about it.

From the original article.

The Nissan LEAF has 12 “fuel bars” that tell you the charge level of the batteries. Just like you were taught to keep your hands on the wheel at 10 and 2, it is a good idea to keep your LEAF’s charge level within 10 and 2 bars of charge.

This in my view is the most important rule to follow. People on this forum seem very concerned about only charging to 80% SOC and then in the same breath talk about running the car to turtle. This seems wrong to me.

A deep discharge is also hard on the battery and should be avoided, just the same as you should avoid charging to 100% SOC and leaving it that way for an extended period of time. Anyhow I like the 10 and 2 rule outlined here.

KJD

 

[Herm]

A deep discharge is also hard on the battery and should be avoided, just the same as you should avoid charging to 100% SOC and leaving it that way for an extended period of time. Anyhow I like the 10 and 2 rule outlined here.

That is the ultraconservative way of managing the battery.

10 bars to no bars is probably ok, there is still quite a bit of charge left in the battery.. charging to 100% is ok if you dont keep it there for a prolonged time. A couple of hours should be fine.

a deep discharge is not that bad unless you reverse the polarity on a cell, but the BMS should stop you before that happens.. it does heat up the cell more than normal but that is ok since the car will soon stop for a long recharge, giving it a chance to cool off. The weakest cell in a series configuration will reach zero voltage first and then go below, a star trek polarity reversal.. the cell will be severely damaged when this happens and may not recover. It will take some time for the BMS to rebalance the pack.

High voltage just breaks down the electrolyte (that will change with advancing tech and different compositions).. I guess that break down is accelerated by high temperature also and time at that state, its sort of a electrolysis or plating process, I cant recall now.

 

[planet4ever]

Anyhow I like the 10 and 2 rule outlined here.

I agree with Herm -- that's too conservative. You may think you are using 8 bars out of 12, but in fact that rule limits you to just over one half of the usable battery capacity. If you want to balance avoiding both the top end and bottom end, consider using 80% to the first Low Battery warning. That will be a bit more than 2/3 of the battery capacity. I have no qualms about going above 80% occasionally, or below LBW occasionally. I prefer not to go below the second, Very Low Battery warning, though I have done it a number of times. I have only gone to Turtle once, and that was intentional. I hope not to do it again.

Ray

 

[dsr302]

From a 80% starting charge, my drive to work ends up with a 47% charge when I arrive there. I plan to recharge using the L2 at work to bring it back to 80%, so I plan to stay within the sweet-spot-range.

However, the L2 at work is in the blazing mid-south sun here in West Tenn where summer time temps exceed 100 degrees frequently. How bad will this be for my battery life if I am charging to 80% while at work?

 

[planet4ever]

From a 80% starting charge, my drive to work ends up with a 47% charge when I arrive there.

Just out of curiosity, how do you know you have a 47% charge when you get there? Please don't tell us it's because you see a big 47 on your dashboard.

Ray

 

[TomT]

Assuming that you have Gary's SOC meter and thus know these percentages for real, I'd not bother charging at work since it is of no real value to battery life. In fact, it may actually even be detrimental... You'd arrive home at over 20% charge which is just fine.

From a 80% starting charge, my drive to work ends up with a 47% charge when I arrive there. I plan to recharge using the L2 at work to bring it back to 80%, so I plan to stay within the sweet-spot-range.

 

[Stoaty]

Assuming that you have Gary's SOC meter and thus know these percentages for real, I'd not bother charging at work since it is of no real value to battery life. In fact, it may actually even be detrimental... You'd arrive home at over 20% charge which is just fine.

Agreed. If your car has to sit in the hot summer sun (like mine does), 50% SOC is the ideal level of charge during that time. I would recommend against charging at work if you want to prolong the life of your battery.

 

[KJD]

Anyhow I like the 10 and 2 rule outlined here.

I agree with Herm -- that's too conservative. You may think you are using 8 bars out of 12, but in fact that rule limits you to just over one half of the usable battery capacity. If you want to balance avoiding both the top end and bottom end, consider using 80% to the first Low Battery warning. That will be a bit more than 2/3 of the battery capacity. I have no qualms about going above 80% occasionally, or below LBW occasionally. I prefer not to go below the second, Very Low Battery warning, though I have done it a number of times. I have only gone to Turtle once, and that was intentional. I hope not to do it again.
Ray

Yes you are correct the 10 and 2 rule is very conservative. My daily commute is less than 20 miles a day so it is pretty easy for me to stay in this area. There have been times that I have charged to 100% but not very often. Same goes for using the last 2 bars. Once in a while buy not very often.

Some people are driving 60 miles to work one way without any problem. Others have already lost the top capacity bar.

When we have had these cars on the road for about 5 years then we will start to find out what works and what does not work well.

Right now it is a lot of guess work. Long term being conservative, might make the pack last longer. Time will tell.

 

[AndyH]

<snip>

When we have had these cars on the road for about 5 years then we will start to find out what works and what does not work well.

Right now it is a lot of guess work. Long term being conservative, might make the pack last longer. Time will tell.

Time may tell, but it's likely that we won't be able to pull any meaningful info from the various practices if for no other reason than cells degrade due to time as well. We have too many variables and skill levels. That's why standardized, controlled testing is so important - and why most info acquired on the road is useless.

 

[Herm]

Time may tell, but it's likely that we won't be able to pull any meaningful info from the various practices if for no other reason than cells degrade due to time as well. We have too many variables and skill levels. That's why standardized, controlled testing is so important - and why most info acquired on the road is useless.

Nissan will have tweaked the chemistry of the batteries within 5 years, throwing all this perfectly good data out the window

It may turn out that the high temps at Phoenix may just overwhelm other aging factors such as time or SOC state...

 

[dsr302]

From a 80% starting charge, my drive to work ends up with a 47% charge when I arrive there.

Just out of curiosity, how do you know you have a 47% charge when you get there? Please don't tell us it's because you see a big 47 on your dashboard.

Ray

Yeah, I was looking at the big 47 staring at me on the dash.....so no, I don't know if the 47% is real, since it is from the GOM....these were test runs using the dealer demo until my Leaf arrives and I definitely don't have a Gid meter set up on it. I really was basing my 47 from the fact that my drive to work is almost all freeway chewing up the electrons with little to no regenerative braking to reclaim the energy so it seemed reasonable at the time.

I like the idea of this number being understated and that I could have effectively more that the big 47 was showing.....plus, I like the idea of not charging at work to pro-long the battery life, especially to off-set sitting in the heat. The battery life issue is concerning.....

 

[davewill]

... Please don't tell us it's because you see a big 47 on your dashboard.

Ray

Yeah, I was looking at the big 47 staring at me on the dash.....so no, I don't know if the 47% is real, since it is from the GOM....

He told you not to tell us that. The "big" number, AKA GOM, is not a % of battery but a guess as to how many miles you have left until the battery is empty. It's worse than useless for any discussion of how much battery you've used since it's weighted to whatever kind of driving you've been doing recently...plus a liberal amount of bad fortune-telling. You want to watch the bars unless you have one of the third party meters.

 

[UkrainianKozak]

Did I miss something?
I don't get why it is bad...
I drive to work, I know that I leave by 5PM, so I set the timer to charge to 80% by 4PM, when I'm home The battery is around 50-60% SOC, where it sits from ~6PM to 8AM at ideal SOC the most possible time.
So the car would spend at most 1 hour per day at 80%, while spending most of the time at ideal SOC.
If I would charge at home, the car would be at ideal SOC only for 8 hours, compared at 14 hours if I charge at work, so to me charging at work seems better...

Assuming that you have Gary's SOC meter and thus know these percentages for real, I'd not bother charging at work since it is of no real value to battery life. In fact, it may actually even be detrimental... You'd arrive home at over 20% charge which is just fine.

Agreed. If your car has to sit in the hot summer sun (like mine does), 50% SOC is the ideal level of charge during that time. I would recommend against charging at work if you want to prolong the life of your battery.