Commute range, SOC

My Nissan Leaf Forum

Help Support My Nissan Leaf Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

tbleakne

Well-known member
Leaf Supporting Member
Joined
Jul 28, 2010
Messages
988
Location
Claremont, CA
mwalsh said:
LakeLeaf said:
Nice video - thanks.

Thank you!

Last part. And now I'm off to bed:

[youtube]http://www.youtube.com/watch?v=ng0dgWXYbeY[/youtube]
Your 3rd video gets you to your office with about 60 miles remaining. I believe you started from home with 105 miles showing, and you said your commute was about 31 mi each way. 105-60 = 45, so about 14 miles went "missing." I am anxious to hear how many miles were showing when you returned home. You said you were going to check what Carwings showed. Is there reason to believe it might be more accurate ?

Your daily commute is going to be a pretty serious test for this car. After you have a week or two of commutes to gain confidence, and assuming the weather permits an absence of climate control, you might want to try starting out with slightly less than 100% charge to be as gentle as possible on the battery. The advice I have heard seems to suggest keeping the battery centered around 50-55% SOC is optimum.
 
tbleakne said:
You said you were going to check what Carwings showed. Is there reason to believe it might be more accurate ?

You can't see the SOC with the car's gauges, but it is on Carwings.
 
tbleakne said:
Your 3rd video gets you to your office with about 60 miles remaining. I believe you started from home with 105 miles showing, and you said your commute was about 31 mi each way. 105-60 = 45, so about 14 miles went "missing."
Miles are an estimate. They change according to how the car is driven. You can consume 60 miles worth of energy while driving 40. That is how you would get 20 miles missing.
 
LEAFfan said:
tbleakne said:
You said you were going to check what Carwings showed. Is there reason to believe it might be more accurate ?

You can't see the SOC with the car's gauges, but it is on Carwings.

I am now convinced that the % SOC in carwings is simply the number of bars showing in the car, multiplied by approx 8.3. It's NOT precise down to 1% and not any more accurate than what the bars tell you. Note that in carwings the % is shown next to a display of the 12 bars. If you watch the car charge via carwings by refreshing at the appropriate times, you'll see the number simply jumps from one multiple to the next, along with each bar. (similarly, the remaining time to charge is only shown to the nearest 30 minutes, it doesn't adjust minute by minute). For example just now I watched my SOC go directly from 67 to 75 all at once. I think you're only ever going to see percentages of 92, 83, 75, 67, 50, 42, 33, 25 etc..
 
tbleakne said:
Your 3rd video gets you to your office with about 60 miles remaining. I believe you started from home with 105 miles showing, and you said your commute was about 31 mi each way. 105-60 = 45, so about 14 miles went "missing." I am anxious to hear how many miles were showing when you returned home. You said you were going to check what Carwings showed. Is there reason to believe it might be more accurate ?

Your daily commute is going to be a pretty serious test for this car. After you have a week or two of commutes to gain confidence, and assuming the weather permits an absence of climate control, you might want to try starting out with slightly less than 100% charge to be as gentle as possible on the battery. The advice I have heard seems to suggest keeping the battery centered around 50-55% SOC is optimum.

30.5 miles each way for a drive of 61 miles r/t.

There were 31 miles remaining that night when I got home. I actually did better with respect to the miles remaining matching what I used going home, but that was probably down to moderate traffic forcing me to keep my maximum speed down and into more regen. What I intended to check through Carwings was SOC as a percentage, but that night I never got to it.

The next day was actually a more consistent drive - I stayed on the cruise control @ 65mph the entire way (except for the 3-4 miles on surface streets) I started out with only 99 miles that morning, but arrived at work with 57 miles showing. So 42 miles "used" and 11.5 "missing".

Coming home that night I left with 56 miles (lost a mile by allowing a coworker to just roll the car forward a couple of feet) and arrived with 27 miles showing. So 29 miles used to drive the 30.5 distance. This was in heavy stop-and-go traffic most of the way.

I also used 9 bars in the car and dipped into the 10th about 2 miles from home.

I haven't figured out yet why miles go missing on the way to work and not on the way home. It could be the freeway speed thing - I've yet to be able to drive home at freeway speeds due to typically heavier traffic on the drive home - or it could be a cold pack thing.

Today I actually join the 80% club (see other thread). I'm charged to 83% right now, with 10 bars showing in the car. I should get home after just dipping into the final red bar, so long as I can keep my average consumption of ~4mpkWh going.

This is what (I think) I've learned so far:

Each bar is worth 1.67kWh (12 divided by 20 - the last 4kWh are under the last red bar as reserve).
Each bar has been worth ~6.6 miles to me (assuming the ~4mpkWh). Call it 6.5 to make addition easier.
 
garygid said:
The service manual contains a description of how the "fuel/SOC" meters operate.

However, they appear to be based upon SOC estimates, not exact values.

But this is the same with all lithium ion batteries it is my understanding - there is no way to know EXACTLY what the stat of charge is... you need to estimate it.
 
mwalsh said:
Today I actually join the 80% club (see other thread). I'm charged to 83% right now, with 10 bars showing in the car. I should get home after just dipping into the final red bar, so long as I can keep my average consumption of ~4mpkWh going.

This is what (I think) I've learned so far:

Each bar is worth 1.67kWh (12 divided by 20 - the last 4kWh are under the last red bar as reserve).
Each bar has been worth ~6.6 miles to me (assuming the ~4mpkWh). Call it 6.5 to make addition easier.
I wish you the best, Mike, but here's my "gloom and doom" prediction:
  • The "battery low" warning will come on 5-10 miles before you get home
  • Climate control may be cut back shortly before you arrive, but that is iffy.
  • You won't experience turtle mode, but if you drove another five miles you would.
  • You are going to have a fair amount of range anxiety, and resolve never to try 80% again.
  • Tonight or tomorrow morning we are going to see a very different statement from you as to what you think you have learned about the bars.
 
planet4ever said:
  • The "battery low" warning will come on 5-10 miles before you get home
  • Climate control may be cut back shortly before you arrive, but that is iffy.
  • You won't experience turtle mode, but if you drove another five miles you would.
  • You are going to have a fair amount of range anxiety, and resolve never to try 80% again.
  • Tonight or tomorrow morning we are going to see a very different statement from you as to what you think you have learned about the bars.

You clearly aren't following my 80% club thread. :D

I have 50% charge and 48 miles of range remaining at the half-way point. I have 4 white bars left and, since I'm getting 6.8-7.1 miles per bar I will probably end up just dipping into the first red. That's my prediction anyhow.
 
mwalsh said:
You clearly aren't following my 80% club thread. :D

I have 50% charge and 48 miles of range remaining at the half-way point. I have 4 white bars left and, since I'm getting 6.8-7.1 miles per bar I will probably end up just dipping into the first red. That's my prediction anyhow.
It's true that I posted my gloomy prediction before I saw your post in the other thread about having 50% left, and I was surprised when I saw that. But I think the "Low battery" warning will come on several miles before you drop down to a single bar. I also think that if you did drop to zero bars you would be in turtle mode. Therein lies the major difference in our hypotheses. You apparently think all the low battery part is after you get to zero bars. We will soon know for sure.
 
planet4ever said:
It's true that I posted my gloomy prediction before I saw your post in the other thread about having 50% left, and I was surprised when I saw that. But I think the "Low battery" warning will come on several miles before you drop down to a single bar. I also think that if you did drop to zero bars you would be in turtle mode. Therein lies the major difference in our hypotheses. You apparently think all the low battery part is after you get to zero bars. We will soon know for sure.

We didn't bet a pizza or anything, did we? 'Cause I don't like giving up my pizza! Check in on the 80% club thread in a little while. Bottom line....I don't wanna be in the 80% Club. :lol:
 
cdub said:
garygid said:
The service manual contains a description of how the "fuel/SOC" meters operate.

However, they appear to be based upon SOC estimates, not exact values.

But this is the same with all lithium ion batteries it is my understanding - there is no way to know EXACTLY what the stat of charge is... you need to estimate it.

This has been covered in the 80% Club thread. There are a number of different cell types/chemistries in the lithium family. Some have flat charge/discharge curves that make it nearly impossible to know the exact state of charge based on cell voltage (like LiFePO4) and there are other types that have sloped charge/discharge curves that make is very easy to know an accurate state of charge based on voltage alone - like the Leaf's LiMn2O4.
http://www.mynissanleaf.com/viewtopic.php?p=50645#p50645
http://www.mynissanleaf.com/viewtopic.php?p=2670#p2670

Yes - the Leaf can use its combination of voltage sensing and current sensing and cell internal resistance and cell degradation logging to know the SOC very accurately. ;)
 
sorry if this been discussed elsewhere, but isn't deep discharge (down to last few miles) worse for battery than 100% charge?
 
Define "deep discharge". If you run down well past the "Low Battery" warning to the point that the miles remaining estimate disappears and is replaced by dashes, the battery is still probably not more than 85% discharged in terms of total capacity.
 
Stunt822 said:
sorry if this been discussed elsewhere, but isn't deep discharge (down to last few miles) worse for battery than 100% charge?


deep discharge in real life is not worse simply because it would be hard to obtain. turtle mode which slows discharge rate from the battery would kick in well before the point where battery longevity due to discharge would come into play.

so the answer to your question is technically yes, but you would have to be in turtle mode for a while. i guess the real question is how far in turtle mode can you go before you risk damage?

will the car just shut down before that point? i guess its possible if you push it enough
 
DaveinOlyWA said:
Stunt822 said:
sorry if this been discussed elsewhere, but isn't deep discharge (down to last few miles) worse for battery than 100% charge?


deep discharge in real life is not worse simply because it would be hard to obtain. turtle mode which slows discharge rate from the battery would kick in well before the point where battery longevity due to discharge would come into play.

so the answer to your question is technically yes, but you would have to be in turtle mode for a while. i guess the real question is how far in turtle mode can you go before you risk damage?

will the car just shut down before that point? i guess its possible if you push it enough
The car will not let us discharge either the entire pack or any single cell below the the 'consumer minimum' capacity. If any cell's voltage rises above or falls below the limits, the car sets a 'hard' error code and enters a 'no drive, no charge' mode. At that point it's flat-bed time.

There is a voltage buffer slightly inside those 'no-go' voltages where the car will simply stop moving (or stop charging) - this is what happens when one keeps driving thru Turtle - the car will just give it all it's got and shut down - just like an ICE that runs out of gas.

Even at this point we're not over-discharging the pack or risking damage - because the energy use is still managed by the battery management computer. The car simply will not let us damage the battery.
 
I think we can modify the question. Let us assume Nissan has reserved top 5 and bottom 5%. So we are talking about 95% to 5%. (it is possible this is the origin of the 95% capacity statement ?)

So, from here - is it worse to hit the 5% regularly or the 95% regularly ?
 
5% would definitely be "worse" but how bad would it be?

if its significantly bad, then Nissan probably does not allow it.

if its only bad if abused long term or iow, only "slightly" bad, then that would be the warning that happens after the creep mode after the initial warning to recharge.

either way, it is not an issue i will lose sleep over since i am charging to the "100%" level even if i expect to do my 20 miles that day.
 
Back
Top