Range and Battery Degradation Survey. Please enter your data

Hello,

I am doing a survey of how the driving range and battery capacity of the Nissan Leaf varies over time. Please help out by entering data about one of your trips in your Leaf. All data is available from the dashboard for 2013 and newer models (2011 owners can enter 0 for SOC). I will do a statistical analysis of the data and post the results on this thread. If a valid statistical model is found, I will also post a spreadsheet which will allow you to estimate your total range in future using your driving conditions.

Take the survey here: https://docs.google.com/forms/d/1bwJgzlP9tz8DFgusqfJ1sBUL1gsaXr26THMvHwBztQI/viewform?usp=send_form" onclick="window.open(this.href);return false;

I understand a number of threads exist on this topic. I am trying to obtain quantitative data in a structured format in order to do an analysis.

Thank you for your inputs.

I believe there is a very quantitative survey (spreadsheet) and comprehensive model already completed, connected to one of those threads.

The Plug-in-America data doesn't work for you?

http://www.pluginamerica.org/surveys/batteries/" onclick="window.open(this.href);return false;

msandeep said:

Hello,

I am doing a survey of how the driving range and battery capacity of the Nissan Leaf varies over time. Please help out by entering data about one of your trips in your Leaf. All data is available from the dashboard for 2013 and newer models (2011 owners can enter 0 for SOC). I will do a statistical analysis of the data and post the results on this thread. If a valid statistical model is found, I will also post a spreadsheet which will allow you to estimate your total range in future using your driving conditions.

Take the survey here: https://docs.google.com/forms/d/1bwJgzlP9tz8DFgusqfJ1sBUL1gsaXr26THMvHwBztQI/viewform?usp=send_form" onclick="window.open(this.href);return false;

Click to expand...

I saw the responses to your post at http://www.mynissanleaf.com/viewtopic.php?p=389813#p389813" onclick="window.open(this.href);return false; and to me, you're seriously over-thinking this. I agree w/the responses there that I skimmed.

Also, the average summer temperature you want in the survey is not that helpful and not granular enough. The crazy temps in the day PLUS the very high temps into the night in Phoenix are what was baking the batteries there: http://www.mynissanleaf.com/viewtopic.php?p=215907#p215907" onclick="window.open(this.href);return false;.

As for your interest in what happens after 50K miles, it totally depends on many factors esp. temperature and calendar losses. From http://www.mynissanleaf.com/viewtopic.php?p=228326" onclick="window.open(this.href);return false;, one Phoenician lost 4 capacity bars within 29K miles in under 21 months.

TaylorSFguy at http://www.mynissanleaf.com/viewtopic.php?f=27&t=12781&p=291620&hilit=+bar#p291620" onclick="window.open(this.href);return false; stated "UPDATE: June 1 - I lost first bar last night at 78,600 miles." (in 2013) on his Leaf that was delivered May 13, 2011. He lives in a MUCH more favorable climate and he drives 130 miles/day on his Leaf, needing to charge at both ends.

From him on June 26, 2014 at http://www.mynissanleaf.com/viewtopic.php?f=31&t=16085&p=374385#p374385" onclick="window.open(this.href);return false;

today (3 years 1+months) - at just over 120,000 miles, bar 3 disappeared. GIDS were 195 this morning. Hit QC twice and it was gone.

Click to expand...

I also can't answer your survey as my commute can vary a fair amount in terms of time, length and speed, depending on when I go and leave. I also DO charge between the beginning and end of trip. I primarily charge at work w/only occasional Friday or weekend charging at home.

Close, but it doesn't have the information I am looking for - a way to estimate range on a full charge as a function of odometer reading and other conditions. It does have responses for "how do you feel range has change", and "typical round-trip distance", but I am looking for more precise data.

drees said:

The Plug-in-America data doesn't work for you?

http://www.pluginamerica.org/surveys/batteries/" onclick="window.open(this.href);return false;

Click to expand...

Besides the issue w/your only wanting average summer temps, which I've already asserted is insufficient. I don't even think cooling degree days is sufficiently granular enough either.

http://usatoday30.usatoday.com/weather/resources/askjack/waskdays.htm" onclick="window.open(this.href);return false; is an example source of info on this.

There has been some misunderstanding about what I am attempting here, so I thought I should clarify. This is essentially statistics 101, but in the context of Leaf's range. The numbers below are purely for illustrative purposes - don't take them seriously. I used the data in this thread for analysis:

http://www.mynissanleaf.com/viewtopic.php?f=31&t=13237" onclick="window.open(this.href);return false;

To build a prediction model, you pick the variable you are trying to predict, the "independent variable". You also need one or more factors which influence the independent variable, or the "dependent variables". In this example I am trying to predict the distance to turtle, so independent variable is "miles", or the trip odometer. The dependent variables are "econ" (miles/KWH) and soc_used, change in dash SOC. If you feed the numbers into a statistics software, you get something like this:


The main output here is the regression equation. I said not to take the numbers seriously, but when I plug in my typical numbers (5.0 economy, 60% soc_used), I get:

miles = -53.7 + 10.5 * 5.0 + 0.904 * 60 = 53.04
That's just about how many miles I typically do every day.

And if I had to predict how many miles I'd get on 80% charge:
miles = -53.7 + 10.5 * 5.0 + 0.904 * 80 = 71.12
That's exactly what my trip odometer + GOM says at end of the day (see my sig)

The other number to note is R-squared. A value of 97% means the model is really good, more specifically, 97% of changes in trip odometer are explained by econ and soc_used alone.

This level of accuracy is probably coincidental. Maybe the person who posted the data has similar car and driving conditions as me. In reality, the model fit and predicted numbers will be less accurate. But if we get accurate numbers for all factors influencing range, a somewhat accurate prediction model can be built.