1 Year "Battery Check" Results

[surfingslovak]

This is how I arrived at my destination yesterday. It could not have been any closer. I knew however that my battery would hold about 20.5 kWh of usable energy these days, and my energy economy was holding fairly steady. Nevertheless, I slowed down considerably and tried to conserve energy towards the end of the trip; I knew that it will be very close. Sorry to hear that kolmstead didn't make it.


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BTW, I used the spreadsheet I mentioned in another thread to predict my range. It's fairly easy in my case, since I largely drive on flat roads with consistent energy economy numbers. The only variables are speed and ambient temperature. This is how my model looked like midway through the trip. It turned out to be quite accurate, thankfully.


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[kolmstead]

Tony, I charged to 100% yesterday afternoon and car was connected to EVSE all night. Not cold here; maybe 45 last night. Battery temp started and stayed at 5 bars today. I charged to 100% a couple of days earlier also, to help with balancing. I started preheat 20 or 25 minutes before I left. Turned off climate control before it showed any draw once I got going.

Good point about 19.5 kWh. One more kWh would have done the job for me today. I hope it got lost during preheat. I miss it!

-Karl

 

[DaveEV]

kolmstead, do you have pre-conditioning set to prefer charging or prefer hvac? Heater can easy pull 5 kW when pre-heating, so if it was running full blast for 20 minutes that would use 1.7 kWh if not plugged in, but being plugged in with 3.3 kW plug power available should only use 0.5 kWh at most.

I wonder if will limit power draw to what the plug can provide if pre-conditioning and set to prefer charging on a 100% charge...

 

[TonyWilliams]

Tony, I charged to 100% yesterday afternoon and car was connected to EVSE all night. Not cold here; maybe 45 last night. Battery temp started and stayed at 5 bars today. I charged to 100% a couple of days earlier also, to help with balancing. I started preheat 20 or 25 minutes before I left. Turned off climate control before it showed any draw once I got going.

Good point about 19.5 kWh. One more kWh would have done the job for me today. I hope it got lost during preheat. I miss it!

-Karl

Ok, the preheating may be an issue, depending on how you have that set up.

19.5kWh is a 7% hit, which to me suggests a 49F-56F degree battery. That would also show 5 temp bars above 50F. You may not think that's cold, but the battery does.

To reiterate, that single temperature bar hides a relatively big variation in battery capacity, particularly when you're pushing it!

 

[planet4ever]

19.5kWh is a 7% hit, which to me suggests a 49F-56F degree battery. That would also show 5 temp bars above 50F. You may not think that's cold, but the battery does.
To reiterate, that single temperature bar hides a relatively big variation in battery capacity, particularly when you're pushing it!

I hope this isn't too far off topic, but I looked up the way the bars relate to battery temperature in the Service Manual and the graph seemed to say that 50°F could be either 4 or 5 bars, possibly even 6. Also that 5 bars could be anything from about 28°F to 80°F :!: There was a tremendous amount of overlap, as 4 bars could be anything from about 23°F to 59°F. Am I really reading this correctly? There is a footnote which may be intended to explain this, but I can't seem to make much sense of it:

NOTE:

• Li-ion battery temperature gauge shows Li-ion battery temperature by correcting it according to the battery capacity. Consequently, the number of lighting segments of Li-ion battery temperature gauge can be different regardless of the same Li-ion battery temperature.
• This graph shows corrected temperatures. These do not agree with the CONSULT temperature shown in data monitor item “BAT TEMP”.

I understand that temperature affects battery capacity at the moment, but why would capacity affect temperature? Incidentally the descriptive text refers to the capacity involved as the "gradual capacity" which I take to mean the long-term diminishing capacity, not any short-term temperature-related capacity.

Ray

 

[TonyWilliams]

Ray, I think you are reading it correct, but that it's as crazy as so many other pieces of the puzzle.

 

[DaveinOlyWA]

those temp ranges for the battery are crazy but is indication of battery core temps. i have been on 4 battery bars for MONTHS. temps run between mid 50's to mid teens. so have to say, the battery core warms slowly and cools slowly. for the trip, the battery was likely colder than ambient temps if trip was done in day time after the Sun came out making the OAT (outside air temp) a useless measurement

 

[LEAFfan]

I started preheat 20 or 25 minutes before I left.
-Karl

There's your problem: There is no need to preheat for 20-25 minutes. That's absolutely a big waste of energy. Five to ten minutes is all that is necessary as all you want to do is make the cabin comfortable when you get in. The same thing goes for A/C. Also, any kind of strong cross or headwind will be a big drain. On a 30 mile trip I consistently got 6.0 and then one night we had a 20-25 mile crosswind, and it reduced it to 5.0 on the exact same trip. If you had no measurable wind, then it was definitely your long preheating.

 

[TonyWilliams]

There is no need to preheat for 20-25 minutes.

Certainly, that depends on the ambient temperature and one's desired comfort level. The guys in the Great White North might disagree with you! Plus, if the car is plugged in, and charging is set to priority, it shouldn't matter if the car was per-heated for the full 2 hours possible.

I am solar powered, so I'm not worried about "wasting" power to preheat. The only range issue with preheat would be using the battery at all.

I consistently got 6.0 and then one night we had a 20-25 mile crosswind, and it reduced it to 5.0 on the exact same trip.

Ya, wind can help (tailwind) or hurt (headwind). Factoring the amount of headwind or tailwind from a crosswind can be done here:

http://www.pilotoutlook.com/calculators/runway-crosswind-calculator" onclick="window.open(this.href);return false;

 

[LEAFfan]

There is no need to preheat for 20-25 minutes.

Certainly, that depends on the ambient temperature and one's desired comfort level. The guys in the Great White North might disagree with you! Plus, if the car is plugged in, and charging is set to priority, it shouldn't matter if the car was per-heated for the full 2 hours possible.

Actually, it has nothing to do with ambient temps. Preheating 5-10 minutes is plenty because you aren't trying to heat up the whole cabin, just to be comfortable when getting in. By doing it longer, just wastes time and energy whether you get it free or not and will only use more of your battery pack. Preheating uses more than 3.3kW hs and even though you are plugged in and no matter what preference, it will take the excess from your batteries. Precooling won't use any of your battery pack while plugged in, but again, you only need 5-10 minutes REGARDLESS of the ambient temp to have a comfortable cabin. So Tony, go ahead and preheat your car for two hours and see what happens instead of conjecturing and theorizing. I've already tried the longer preconditionings and all it did was lower my SOC with preheat and with precooling it made hardly any difference. After two hours, I still had to use my A/C as soon as I pulled out of our garage and it gained me nothing more than 5-10 minutes would have done.

 

[DaveinOlyWA]

I timed a preheat when it was 22°. The fan starts at low speed until the air is warmed up then speeds up. That take 5-6 minutes. After that the cart is toasty in a few minutes at most. I think anything longer than 10 minutes is a waste

 

[TonyWilliams]

There is no need to preheat for 20-25 minutes.

Certainly, that depends on the ambient temperature and one's desired comfort level. The guys in the Great White North might disagree with you! Plus, if the car is plugged in, and charging is set to priority, it shouldn't matter if the car was per-heated for the full 2 hours possible.

Actually, it has nothing to do with ambient temps. Preheating 5-10 minutes is plenty because you aren't trying to heat up the whole cabin, just to be comfortable when getting in.

I'm not sure that you even realize that you're imparting your Phoenix environment preheating experiences with every other scenario elsewhere in the world. Having grown up myself in a place that frequently hit -20F to -30F (and still the coldest recorded spot in the lower 48 states), your 5-10 minute view just_wouldn't_work. You are free to believe otherwise. Yes, LEAFfan, ambient temp matters.

Secondly, you seem to know what every other human on the planet would find adequate temperature wise in their preheated car. Let me suggest you don't, and five or ten minutes of preheat in extreme ambient temperature wouldn't get thick frost off the windshield, let alone preheat the car much.

Preheating uses more than 3.3kW hs and even though you are plugged in and no matter what preference, it will take the excess from your batteries. Precooling won't use any of your battery pack while plugged in, but again, you only need 5-10 minutes REGARDLESS of the ambient temp to have a comfortable cabin.

So, if I preheat my 70F car, it will take more than 3.3kW ? (I assumed you meant kW and not "kW hs"). Of course not, because the temp does matter.

So Tony, go ahead and preheat your car for two hours and see what happens instead of conjecturing and theorizing.

I actuall do, everyday. Thanks for once again using your super ESP and determining what others are doing.

I've already tried the longer preconditionings and all it did was lower my SOC with preheat and with precooling it made hardly any difference. After two hours, I still had to use my A/C as soon as I pulled out of our garage and it gained me nothing more than 5-10 minutes would have done.

And you can't fathom how your experiences might_not_be_the_same in Phoenix, as they might be in Edmonton or Oslo in the winter? I think your ESP needs a tune up.

 

[LEAFfan]

Read Dave's post Tony. You must be different than anyone else. I would say 22 degrees F is pretty cold. So it isn't just myself that has learned how not to waste time and energy, but you go right ahead and keep preheating for two hours, just don't recommend it to others.

 

[TonyWilliams]

Read Dave's post Tony. You must be different than anyone else. I would say 22 degrees F is pretty cold. So it isn't just myself that has learned how not to waste time and energy, but you go right ahead and keep preheating for two hours, just don't recommend it to others.

I haven't recommended any period of preheat to anybody, have I ?

I only stated that 2 hours was possible, while plugged in, and I'll add that only 15 min when not plugged in. Further, I stated that your 5-10 min of preheat doesn't fit everybody. Finally, I use two hours because I don't know what time I'll be leaving in the morning, so I just pick the maximum 2 hours. Obviously, this neither wastes my time, nor my free sun rays of energy.

I don't presume to tell somebody when they've had enough heat, as you do.

22F is plenty cold. I doubt the cabin was at the regulated 25/77F in 5 to 10 minutes.

Folks, beyond the banter here, LEAFfan makes a valid point that if your heater does draw more than 3.3kW that the charger is capable of providing, you would have a net loss of battery power. To the folks in the Great White North, let us know how that 5-10 minutes of preheat is working!

Edit: I will make a recommendation for preheating: use enough to at least get that initial power draw from the heater to a more stable range, which should at least get the liquid heater warmed up enough to not exceed that 3.3kW draw with continued preheat (while plugged in).

If you're plugged in or not, and range doesn't matter, heat all you want. If range does matter, and If you're not plugged in, I'd recommend perhaps no pre-heat or Climate Control use while underway.... brrrrrrr.

 

[EVDRIVER]

Tony, I charged to 100% yesterday afternoon and car was connected to EVSE all night. Not cold here; maybe 45 last night. Battery temp started and stayed at 5 bars today. I charged to 100% a couple of days earlier also, to help with balancing. I started preheat 20 or 25 minutes before I left. Turned off climate control before it showed any draw once I got going.

Good point about 19.5 kWh. One more kWh would have done the job for me today. I hope it got lost during preheat. I miss it!

-Karl

Why are you under the impression the pack "needs help with balancing" by charging to 100%. Do you have some detailed data that your pack is out of balance and the BMS is not functioning properly and that the engineers believed consumers would do pack balancing using their own improvised manual techniques.

 

[DaveinOlyWA]

I think my only requirement on pre heating is that it still be running when I get in the car. We may whine about the heater but it works more than well enough to keep us warm in the worst of conditions and it heats up an uninsulated area which means as soon as it goes off its right back to cold in a very short period of time. Running it longer will not "heat soak"the car

 

[TonyWilliams]

I charged to 100% a couple of days earlier also, to help with balancing.

Why are you under the impression the pack "needs help with balancing" by charging to 100%. Do you have some detailed data that your pack is out of balance and the BMS is not functioning properly and that the engineers believed consumers would do pack balancing using their own improvised manual techniques.

I don't get all that out off his simple comment. While I can't answer for him, I presume that he does not believe any of your suggestions.

Clearly, he makes no references to manual techniques. Let me ask you, under what parameters do you think the cells become balanced by the automation provided?

 

[TonyWilliams]

Running it longer will not "heat soak"the car

I know that I've "preheated" more than a few cars, long before the LEAF, in conditions far colder than 20F, and I definitely wanted the car (in extreme cold) to be "heat soaked"! I seldom did that, and usually got in a car so cold that the fan belt squealed, the plastic cracked and groaned, and didn't run too well for the first few minutes.

Granted, a gas burner takes a long time to warm up the liquid part of the heater, even with plugged in heaters for the "coolant", it still took a significant amount of time to warm up the cabin.

It's great that your system works for you.

 

[EVDRIVER]

I charged to 100% a couple of days earlier also, to help with balancing.

Why are you under the impression the pack "needs help with balancing" by charging to 100%. Do you have some detailed data that your pack is out of balance and the BMS is not functioning properly and that the engineers believed consumers would do pack balancing using their own improvised manual techniques.

I don't get all that out off his simple comment. While I can't answer for him, I presume that he does not believe any of your suggestions.

Clearly, he makes no references to manual techniques. Let me ask you, under what parameters do you think the cells become balanced by the automation provided?

He implies he needs to charge to 100% to balance the pack. Clearly Nissan has methods to balance the pack if needed. They would never leave it to owners to do this if required by charging to 100%. Many people will always charge to 80% or less so if they do for the life of the pack and balancing were actually required it would be provisioned in the software by some means. Charging to 100% does not in any way mean one is balancing a pack if it is not out of balance nor that it is ever needed. Out of curiosity I called nissan CS about this and they said "the electrons are balanced in each cell regardless of the SOC because all the modules are parallel. :lol: :lol: Those are some high voltage modules. I love how they make stuff up.

As far as preheating my car takes a long time for some reason but once it's off it looses the heat fast. The best function is to get the poor water -based system up to speed before one leaves and to heat inside surfaces that radiate cold temps to reduce wait time.

I plan to run my own battery check before I go to the dealer for my one year inspection. All the real battery data is sent to Nissan corporate without the dealer ever knowing what is included in the details.

 

[jkirkebo]

There is no need to preheat for 20-25 minutes.

Certainly, that depends on the ambient temperature and one's desired comfort level. The guys in the Great White North might disagree with you! Plus, if the car is plugged in, and charging is set to priority, it shouldn't matter if the car was per-heated for the full 2 hours possible.

Actually, it has nothing to do with ambient temps. Preheating 5-10 minutes is plenty because you aren't trying to heat up the whole cabin, just to be comfortable when getting in. By doing it longer, just wastes time and energy whether you get it free or not and will only use more of your battery pack.

It has everyting to do with ambient temps. 5 minutes won't even begin to melt the ice on the windshield, 15 minutes is minimum useful duration here now. I've had to go to 20-25 minutes after the car sat for 4 days in 4 F temperatures. And I need to heat the interior up, not just the air. If the duration is too short, I can feel the cold radiating from everything and the heater has to run full blast for a while to keep the heat up.