Suggestions on how to maintain battery life in hot weather

[cash4solar]

I feel for those that have lost a capacity bar prematurely but, now maybe we should try to focus on ways to prevent, as much as possible, losing more battery life prematurely. I would love to hear any suggestions. I live in Albuqerque where the temp. gets close to 100 frequently in the summer but cools down to the 60's at night.

I am far from an expert but, I am wondering if hypermiling, putting the car in Neutral going downhill, could help? I know that Nissan warns against doing this because of the possibliity of your brakes overheating but, I intermittently use eco mode to slow the vehicle down (instead of the brakes) and then go back into neutral to maintain speed. I also park my car outside at night to cool the car off as much as possible. Will this help?

I have heard we should discharge shallowly, charge to 80% or less and avoid the quick charge but, I was wondering how long after we drive the car should we wait before charging it again and, how soon after we charge the car should we wait to drive it?

I love my Leaf and am really hoping to drive it into the ground. Which BTW, reminds me of another question. I only drive 15 miles round trip to work. At what point, in terms of bars and or % of capacity left, will I become unable to make a 15 to 20 mile trip? Assuming I am going flat at 45 mph. I am relatively new Leaf owner so, forgive my ignorance.

So many questions, I know. Thanks to all who take the time to reply. I appreciate all the info. on this site, past and present.

 

[LTLFTcomposite]

What about a car cover?

 

[TimLee]

With 80% charging, and full non-depleted battery capacity, the battery has at least 70 mile range. More than that at 45 mph.
So with only a 20 mile round trip commute, the LEAF should be usable for your commute for a long time. Probably greater than 100,000 miles on the vehicle, at least 5 to 8 years of use.
But experience with the degradation rate of the LEAF batteries is very limited.
Keeping battery in the 20% to 80% charge range is probably best for limiting capacity degradation.
Other factor is heat.
If battery temperature is still normal, I don't think that waiting to charge is necessary.

 

[cash4solar]

But what is "normal"? My Battery temp has consistently been reading 6 bars. I know 7 is still considered normal but, some of the Arizona users reported being in that range most of the time.

I would like to drive the car at least 128 K. That is what I am shooting for anyway. Thanks.

 

[Stanton]

But what is "normal"? My Battery temp has consistently been reading 6 bars. I know 7 is still considered normal but, some of the Arizona users reported being in that range most of the time.

If you're always (even mostly) @6TB, you have nothing to worry about; that means you NEVER cross over the 100 degree threshold. The reason 7TB (consistently) is a concern is you may be approaching the 125 degree threshold, which is bad long-term.
Bottom line: your range requirement is so small and your night-time temps are so mild, I don't think you have anything to worry about.

 

[GaslessInSeattle]

as has been said, we have little hard data to go on. If you are only driving 15 miles a day, I'd cycle the battery more towards the middle of the pack. if I were you I would charge the car to 50%/5 bars on a daily basis and run an experiment through the summer. We know that there seems to be little difference in battery decline between those who are charging to 80% vs 100% in hot climates. I have a feeling that 80% in hot whether is still high enough for rapid decline. Everything I've read suggests that 30-50% SOC is the happy place for Li-ion and I suspect there will be an appreciable difference in decline in hot climates for packs kept at a low SOC... and it's time to find out! We'd all appreciate it if you were willing to give this a try and keep good records of range/capacity.

 

[abasile]

Does your battery temp get down to five bars overnight? If so, when does it go back up to six bars?

If I had a 20 mile roundtrip commute and wanted to be super gentle with the battery, I would probably charge to about 60-65% (seven or eight bars), assuming you'd get home with at least 35% (three bars). This still leaves plenty of margin for sidetrips as needed.

I wouldn't bother shifting into neutral. I'd avoid jackrabbit starts and apply power steadily and gently. Lower power levels generate far less heat when driving.

 

[KJD]

I feel for those that have lost a capacity bar prematurely but, now maybe we should try to focus on ways to prevent, as much as possible, losing more battery life prematurely. I would love to hear any suggestions. I live in Albuqerque where the temp. gets close to 100 frequently in the summer but cools down to the 60's at night.

I am far from an expert but, I am wondering if hypermiling, putting the car in Neutral going downhill, could help? I know that Nissan warns against doing this because of the possibliity of your brakes overheating but, I intermittently use eco mode to slow the vehicle down (instead of the brakes) and then go back into neutral to maintain speed. I also park my car outside at night to cool the car off as much as possible. Will this help?.

Parking where it is cool is a good thing. 60's at night is good for this car.

When it is over a 100 then I try avoid hard driving. Low amperage draw keeps the heat low.

I like to see the regen going down hills and I never put it in neutral downhill. The regen will help you avoid deep discharges.

I have heard we should discharge shallowly, charge to 80% or less and avoid the quick charge but, I was wondering how long after we drive the car should we wait before charging it again and, how soon after we charge the car should we wait to drive it?

Most of the time I only charge to 80% and the timer is set to finish just before morning commute. Leave the start time blank on the charge timer.

I love my Leaf and am really hoping to drive it into the ground. Which BTW, reminds me of another question. I only drive 15 miles round trip to work. At what point, in terms of bars and or % of capacity left, will I become unable to make a 15 to 20 mile trip? Assuming I am going flat at 45 mph. I am relatively new Leaf owner so, forgive my ignorance.

My commute is also short. I try and not use the top 2 bars or the bottom 2 bars. However if I need the max range I have no problem charging to 100% and then driving away.

The Leaf can do 80 miles on a full charge, so you would have to loose 3/4 of the pack to get down to 20 mile range.

 

[jspearman]

But what is "normal"? My Battery temp has consistently been reading 6 bars. I know 7 is still considered normal but, some of the Arizona users reported being in that range most of the time.

I would like to drive the car at least 128 K. That is what I am shooting for anyway. Thanks.

I've been sitting on 7 bars for a while now and haven't seen anything less. Parking outside would be of limited value, since it's 10:30pm in Phoenix right now and still 97 degrees, not to mention that my Blink charger isn't outside. It only gets more brutal until September, so I am fully anticipating a second bar loss by then. The only solution would be to air-condition my garage while charging, but that's not feasible for several reasons.

I think all stopgap measures are of very limited value at this point. It's very clear to me that the only solution for Phoenix is a true TMS. I have to believe Nissan is working on this as we speak.

 

[mark13]

No, hypermiling or putting the car in neutral while driving down hill will not help..I avg 6.0 M/KWH and still lost 2 bars..Keep the battery-pack as cool as posiible doing the summer,110 degree heat will kill it....

I feel for those that have lost a capacity bar prematurely but, now maybe we should try to focus on ways to prevent, as much as possible, losing more battery life prematurely. I would love to hear any suggestions. I live in Albuqerque where the temp. gets close to 100 frequently in the summer but cools down to the 60's at night.

I am far from an expert but, I am wondering if hypermiling, putting the car in Neutral going downhill, could help? I know that Nissan warns against doing this because of the possibliity of your brakes overheating but, I intermittently use eco mode to slow the vehicle down (instead of the brakes) and then go back into neutral to maintain speed. I also park my car outside at night to cool the car off as much as possible. Will this help?

I have heard we should discharge shallowly, charge to 80% or less and avoid the quick charge but, I was wondering how long after we drive the car should we wait before charging it again and, how soon after we charge the car should we wait to drive it?

I love my Leaf and am really hoping to drive it into the ground. Which BTW, reminds me of another question. I only drive 15 miles round trip to work. At what point, in terms of bars and or % of capacity left, will I become unable to make a 15 to 20 mile trip? Assuming I am going flat at 45 mph. I am relatively new Leaf owner so, forgive my ignorance.

So many questions, I know. Thanks to all who take the time to reply. I appreciate all the info. on this site, past and present.

 

[Nekota]

I'm thinking that adding some reflective insulation to the bottom 'fiber panel' of the car could be helpful for reducing heating from the pavement. However if the battery is getting heat from flowing air then this would be of limited value. The temperature data from TickTock http://www.mynissanleaf.com/viewtopic.php?f=30&t=9314&start=0 clearly shows a shift to cooler temperatures at 6AM and heating at 6PM. I suspect the air temperature 1 foot off the pavement at 6 AM was in the high 80s and the temperature at 6PM would have increased to 110 would explain these thermal patterns.

If it is the air flow then a diverter (possibly temperature controlled) would direct the hot air away from the battery cavity to reduce heating and toward the battery for cooling.

Heating from the cabin could be reduced by using the windshield shades and rolling down the windows an inch to provide hot air escape. Of course parking in the shade is even more helpful if it's available.

 

[jspearman]

Perhaps I will fill up the floorboards of my car with ice before my wife leaves for work and before I begin charging at night It's either that or I get a portable air-conditioner mounted on a trailer and install a J1772 plug on the unit. This could work. I should submit this scenario to Nissan Customer Service, to add to their arsenal of brilliant suggestions for ailing Phoenix Leaf owners.

I really need to laugh at this situation to keep my sanity.

 

[cash4solar]

Here are a couple suggestions to help keep your car a little cooler. How about if people painted their roofs with a reflective white paint? That lowers the temp in the garage by 10 to 20 degrees and could help keep the battery a little cooler. Also, for those of you with Solar Panels, how about placing them on the roof right above the garage. The panels will offer some insulation form the sun.

I accidentally misrepresented my usage of the Leaf in my last post. My commute is only 15 miles and I asked about capacity loss as it relates to that commute because I was hoping I could use the car even as the capacity went way down however, currently I am not using it just for my commute. My wife also uses it for her 36 mile round trip commute so, I don't think my data would help anyone.

Hypermiling alone I know will not solve the problem, however, I have to believe it could help. When I hypermile and am cafeful driving my 15 mile commute, the dash usually tells me I have a 50 minute charge to get to 80%. When I don't hypermile, the dash tells me I need to charge the car for an hour and 30 minutes. I haven't measuered the real times but, I know it is longer when I don't hypermile. Which brings me to this, How much does charging the battery actually heat the battery pack? Does anyone know?

As far as leaving your car outside, I still plan to do so because, as I understand it, the battery pack takes time to react to the temperature around it. That is why they say in the manuel not to expose the battery to extreme heat for more than 24 hours. So, if I lived in Phoenix, and I knew the low for the night was going to be in the mid to upper 80s, as it has been, I would definately leave the leaf outside. Perhaps it could cut the temp a few degress and perhaps, that few degrees could keep the battery alive a little longer.

Finally, let me say this, I don't think we know yet how 5 bars, 6 bars of even 7 bars will degregate the battery. We are still learning. For that reason, I think it is important to keep the battery temp as low as we can during hot weather because, at this point, I don't think we know what we are dealing with. Six months from now people with 6 bars could be losing capacity also. Better safe than sorry. I park under a tree almost every day for that reason.

Good luck everyone and keep the suggestions coming, please.

 

[cash4solar]

Today was my last day of Hypermiling. I won't be doing that anymore. Too many crazy drivers make this practice unsafe so, I can not recommend it to anyone. I was hoping to make the batteries last a little longer but, it just is not worth it. Not to mention the fact that it is probably harder on your gear box. Good luck to everyone.

 

[EricBayArea]

HHow about if people painted their roofs with a reflective white paint? That lowers the temp in the garage by 10 to 20 degrees and could help keep the battery a little cooler.

Others on this forum have pointed out that car color does not matter (much). You may see a very slight difference in cabin temperature but by and large, the difference is negligible. And besides, the larger issue is radiant heat off of the asphalt/ground since when you are parked, there is no air flowing from the cabin into the battery compartment - it is all coming from the ground where it has been baking.

Reading this article, when it is around 100 degrees in Las Vegas, the concrete sidewalk may be 127 degrees and the black asphalt may be 147 degrees. Assuming you are parked above asphalt you have 147 degrees of radiant heat rising in the direction of your batteries. The heat in your car will increase to around 130+ if left alone in 100 degree weather.

Best bet would be to create a small pool base that you can park over and fill it with water when you get home. That way you don't have the 127-147 degree heat radiating up. Also, I would think that if you can spare the electricity and you are running errands, leave the AC running to keep cool air flowing to the batteries. Or as someone has suggested, paint parking spaces white

 

[DaveinOlyWA]

if it can be managed i would never charge over say 60% and if you drive 15 miles a day, that is what i would do. but how often do you have unexpected errands within the Leaf's range that might be say 40 or 50 miles RT? not being able to drive the Leaf in those situations would be criminal in my situation since that is the purpose i got mine.

i have never used the 80% charging setting choosing to manually charge to a level i felt i would need which means some days not charging at all to charging just a few hours. i simply set an alarm on my cell based on how far to charge.

now, up until the past 4 months i rarely charged to 100% in order to help preserve my capacity and that has probably proven to be a baseless concern in my situation.

i got pretty adept at being able to charge to 90-95% when i needed it (of available capacity) regularly hitting 260 GID doing so because was guesstimating that charge rates would start to slow making my efficiency lower (already only charging at 12 amp on EVSE mod)

but right now, i am at 220 GID and expect to do about 50 miles of mixed driving today so probably be around 50-70 when i park it keeping in mind that is only a stone's throw from LB (around 46-49 if you are interested) and most would probably want more of a cushion but this 50 miles will be 4 different errands spread out between 1 pm and 11 pm (fireworks thingy...normally hibernating waaay before then!)

but if something else comes up, opportunity charging around town can be had in 20-45 minute bursts plus a 10 minute pit stop at the DCFC is not out of the question

anyway i have wandered around the block on this topic...sorry for that. bad habit i know and i keep planning to address that issue :?

but in your modest needs, i think you have little to worry about. just keep the pack SOC lower.