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Re: What SOC% does each bar on Leaf dash represent ?

Posted: Wed Aug 03, 2011 10:30 am
by davewill
The only thing I know is that multiplying the dashboard mpk numbers by 21 kWh (or 17 kWh for an 80% charge) results in range numbers that match my experience. For instance, freeway driving at 60 mph, I can reliably get 4.1 mpk or so. Multiplied by 21 kWh, that results in a range of 86 miles, which pretty closely matches my experience. Multiplying by 24 kWh gives me 98 miles, a number I know I can't reach driving at 60mph.

It's all handwaving and guessing...the real number could be more or less than 21...it could even be 24 and the mpk readout is off. The only thing I care about is being able to reliably predict range. Using 21 kWh does the trick.

Re: What SOC% does each bar on Leaf dash represent ?

Posted: Wed Aug 03, 2011 9:43 pm
by garygid
Energy to fully charge might be 26 kWh, the "usable" energy stored in the battery might be 24 kWh, and the energy RECOVERED from the battery for use might be 22 kWh.

Thus, 26, 24, AND 22 might ALL be "correct".

Re: What SOC% does each bar on Leaf dash represent ?

Posted: Wed Aug 03, 2011 10:41 pm
by TonyWilliams
garygid wrote:Energy to fully charge might be 26 kWh, the "usable" energy stored in the battery might be 24 kWh, and the energy RECOVERED from the battery for use might be 22 kWh.

Thus, 26, 24, AND 22 might ALL be "correct".

I think you win the prize. Heck, we're all winners !!!

:mrgreen:

Re: What SOC% does each bar on Leaf dash represent ?

Posted: Wed Aug 03, 2011 10:50 pm
by TonyWilliams
davewill wrote: Multiplied by 21 kWh, that results in a range of 86 miles, which pretty closely matches my experience. Multiplying by 24 kWh gives me 98 miles, a number I know I can't reach driving at 60mph.
My numbers are right in line with yours, and I've taken this car down to turtle 4 times to verify them. I use 81 miles of range estimate at 60mph, and 72 miles at 80% on my latest chart. The super important numbers (to me, anyway) are when you're down to below both any fuel bars and (thankfully) Guess-O-Meter numbers, and only have the Battery warnings to judge distance. I'm very confident, now, what distance I can go.

Of course, it would help me if I had a bit more battery in the car !

It's all handwaving and guessing...the real number could be more or less than 21...it could even be 24 and the mpk readout is off. The only thing I care about is being able to reliably predict range. Using 21 kWh does the trick.
Exactly. I really don't care what the kW number is, except what I'm paying for out of the wall. What we all should care about is the range.

Re: What SOC% does each bar on Leaf dash represent ?

Posted: Thu Aug 04, 2011 6:15 pm
by pkitchen
I find all the discussion, calculations, and personal systems for estimating range fascinating and informative, but I recently discovered the best range estimate is already provided by Nissan... It's the white range circle on the Nav display!

Bear with me here. After much data gathering and observation. I've proven to my satisfaction that the following are true:

1. The only thing that really matters is how many miles you actually travel for each bar shown on the battery gauge.
2. Obviously the number of miles you get per bar varies, but you can reset the trip odo's to keep track.
3. The car is keeping track of this and uses an averaging algorithm to drive the inner white range circle display.
4. This "white circle" display is the REAL range you will get despite the other 'optimistic' figure displayed in the cluster.

So here's the deal. That 'optimistic' number on the cluster is really nothing more that what MIGHT happen and it appears on the Nav range display as the outer "gray" circle. It is the "best case" scenario whereas the inner white circle range on the NAV display is the minimum range as predicted by the ACTUAL miles you are getting per bar. In my experience it is the inner range bar that is highly accurate and easy to use and track!

Check it out for yourself and let me know if what I have observed holds true!

Re: What SOC% does each bar on Leaf dash represent ?

Posted: Fri Aug 05, 2011 11:20 am
by surfingslovak
TonyWilliams wrote:My numbers are right in line with yours, and I've taken this car down to turtle 4 times to verify them. I use 81 miles of range estimate at 60mph, and 72 miles at 80% on my latest chart. The super important numbers (to me, anyway) are when you're down to below both any fuel bars and (thankfully) Guess-O-Meter numbers, and only have the Battery warnings to judge distance. I'm very confident, now, what distance I can go.
Tony, I took some liberty with your chart. It's speculative, but I think plausible. Have a look:

Image

Re: What SOC% does each bar on Leaf dash represent ?

Posted: Sat Aug 06, 2011 1:32 am
by planet4ever
I can believe 8 miles per bar at 45 in a rural or expressway environment, but I can't get anywhere close to that on city streets if my average speed is 20. I'm probably a lousy driver, because I only got 7 miles per bar when I ran a rural 45 mph test (heat and A/C off, round trip, nearly level), but I get more like 4 miles per bar driving short trips around town with speed limits 25-35 and lots of non-timed traffic signals. (Yes, I do try to look as far ahead as possible and slow before I get to a red light.)

Ray

Re: What SOC% does each bar on Leaf dash represent ?

Posted: Sat Aug 06, 2011 1:44 am
by TonyWilliams
planet4ever wrote:I can believe 8 miles per bar at 45 in a rural or expressway environment, but I can't get anywhere close to that on city streets if my average speed is 20.

Ray, you have the answer right there. Average speed of 20 will not got good mileage. 20-45 mph averages out to 32.5 mph. But, it's not that scientific. There are just too many variables in stop light, around town driving. If you sit at lights longer, accelerate faster, let regen do 90%+ of your braking, etc.

The steady speeds are much easier to predict. Check out this post where I compared the actual numbers with the chart predictions.

Re: What SOC% does each bar on Leaf dash represent ?

Posted: Sat Aug 06, 2011 2:02 am
by TonyWilliams
surfingslovak wrote: Tony, I took some liberty with your chart. It's speculative, but I think plausible. Have a look:

Awesome. Why isn't 281 valued at 100% ?

As to the total usable kW, it would be handy. My trip today averaged 52mph, and 4.4miles/kWh.

If I can go 96 miles at 50mph, and 4.4kWh leaves us with 21.8 usable battery. I'm not even sure if this usable is static. For instance, if I'm really working the battery hard, is it less efficient (meaning a higher percentage of energy is lost as heat?).

The 81 mile range at 60mph is 3.7 miles/kW/h at 21.8 usable. I think I'm a couple miles short on absolute range, however.

This will all get more difficult as the batteries age.

Re: What SOC% does each bar on Leaf dash represent ?

Posted: Sat Aug 06, 2011 10:40 am
by evnow
I've updated the OP with the chart for the new firmware. I made the chart a month are so back, and I somehow thought I had updated the chart. Apparently not.

ps : Ok, I did update the chart - but not in this thread !

http://www.mynissanleaf.com/viewtopic.p ... 72#p109272