Re: What SOC% does each bar on Leaf dash represent ?
Posted: Fri Sep 16, 2011 6:51 pm
Thanks, good information. This should be part of the FAQ on the Wiki.
The forum for all aspects of the Nissan Leaf
Which means if you are buyinga second hand LEAF you'll need an SOC meter to see what it registers when full.garygid wrote:Wow!
Nissan "hides" Capacity loss until 15% is lost (85% remains), and only then do they drop theb12th Capacity-Bar, making you think that you only lost 1/12th (8.3%) but you have actually lost almost TWICE that amount (15%)?
I suspect the turtle mode decision is based on individual cell voltages.LakeLeaf wrote:OK - trying to understand some of the inner workings a bit more.
So have you been able to figure out - when the car takes a particular action - e.g. going into turtle mode - does it do it based on the actual SOC number, or based on the projected range number?
The later would seem to explain some of the outlier reports we've read, but it also seems to be a strange way to take action.
My comments are based on my knowledge of laptop battery performance/operation, and my background as an electrical engineer working with microcontrollers, sometimes within laptops. (Consider researching how laptop battery controllers estimate remaining charge, i.e. "gas gauge" functions.)surfingslovak wrote: ....
What exactly is the model then? It's essentially an approximate SOC point to kWh mapping. The mapping itself is speculative, but it seems to be be in alignment with other observations voiced on this forum and with the data gleaned from the few and far between comments from Nissan. I also found some very helpful information on the Tesla owners forum, and I believe that the Leaf is much closer to the Roadster in terms of charging protocols and battery care than we think or Nissan has admitted.
But back to the model. SOC 281 is not valued at 100%, because it very likely does not represent 100% pack capacity. It's the full available charge, which is less than 24kWh for the sake of battery longevity. The mapping I'm proposing assumes 320 SOC points representing 24kWh. Each point would be 0.075kWh or 75Wh. There is a silent reserve on both ends. It's likely 20 points below zero, that's what's left in the pack when the Leaf stops dead after turtle. There are another 19 points above 281 to make it full 320 SOC points. I took this metric and added pack SOC % and kWh estimates to your chart.
Try a 100% charge cycle....GregH wrote:Ha! No! You're absolutely right.. I even started a separate thread... I want my 281! Lately the lowest I've seen is 271# and the highest 274#. The all time highest I've seen on my car was 280# but that was a while ago... The car is nearing 2000 miles and 3 months and rarely spends much time over 80% (or 225#) or under 20% (or ~50#)TonyWilliams wrote:Your car shouldn't get the same SOC number all the time. Do you ALWAYS get 272 on a full charge?
(other) Gary, that's one for the 'most obscure Leaf facts - way out there' thread.garygid wrote:As the LEAF's Battery Pack loses Capacity over time, at perhaps 16% loss only 11 of the 12 small Capacity-Bars will be lit.
However, when you "fill" the Pack (a 100% charge) apparently the LEAF will still display 12 fuel-Bars, as if to say that your SMALLER fuel tank is FULL.
However, then each fuel-Bar will represent LESS energy than it did when the Pack was new. Personally, I think that this choice, if it is indeed what the LEAF does, is a very misleading choice!!!
From this, we assume the "gid" value will still read about 281 when 100% full. We have not found the "capacity" value in the CAN data, but we see the "Fuel-Bars" (0-12) count, and a related 12-value that is likely to be the Capacity-Bars.
I have a rule of thumb I use to determine where in a bar I am, and have been quite successful in predicting a bar going out within a few hundred yards!!EVDRIVER wrote:An 8% variance could be eight miles or more depending, not exactly a useful scale. If one was not watching and the bar just shifted one would not know if the bar were about to go down any minute or had just gone down making the estimation even more difficult.
Thanks! That's a useful tip! I will assume this applies only to "like new" batteries.JPWhite wrote:Then I do a quick mental calculation, each bar takes approx 1 1/2 hours to replenish at 120v, the gauge indicates time to recharge at both 240v and 120v. So if 4 bars are extinguished, that would translate to 6 hours at 120v. When the estimate reaches 6 1/2 hours I know that I have consumed some of the next bar and that it will extinguish fairly soon.
So the basic formula is # bars X 1.5 hours + 30 minutes. Once this point is reached for the 120v recharge estimate the bar will go out in about 1/2 mile.
The first bar seems to be a special case, it will extinguish shortly after the estimate reaches 50 minutes to recharge at 120v.