A more personalized est driving range calculation???

Since getting my Leaf about 2 wks ago I've been perturbed by the GoM number, which never really reflects my normal driving habits. When I hop into my Leaf in the morning after a full charge (I no longer do full charge, but I was initially), I'm excited to see GoM number showing 104 miles. Later in the day, this is replaced with saddness and disbelief that I really only got ~70 miles, due in large part to > 80% driving on highways. I thought for sure the GoM would adapt and show a more accurate number for the next day. But alas, no. It's as if the GoM always anticipates that I will only go 35 MPH in urban street driving.

Ok, no problem. I can adapt. I will block out the GoM number from my mind. I will put something in front of it and use a different system. After hours of reading thru expert posts (I'm sure I will need 1000's of more hours), I believe I've put together enough information to come up with a more accurate estimated driving range for me.

From what I've read from other more seasoned members, I'm sure there are many that can determine if my calculations are correct.

First off, since my battery hasn't had time to have any degradation, I will assume that
A1) 100% charge = 21 kwh
or,
A2) 80% charge = 17 kwh

If I'm not at exactly 100 or 80% charge, I need to determine how many kwh are remaining. I can look on the Estimated Charge Time display.

B) # of kwh used = 0.8 x (# of 120v hrs to charge)

C) Remaining kwh = A(1 or 2)-B

Now to convert that into how many miles I have left I look on the Navgation consule -> Menu -> Energy Info

For the past two weeks I've been avg 3.9 miles/kwh. But I'm going to be conservative and say 3.5 miles/kwh.

So then, my total miles left = C*3.5

When I apply this to the 'Battery Available Charge Gauge' (not to worried about Capacity Level Gauge since my batteries are relatively new), I get these new (and hopefully more accurate to my driving habit) values:

Range est @ 3.5 mile/kwh
Charge/Bars
100%/12 = ~74 miles

80%/10 = ~60 miles

75%/9 = ~55 miles

50%/6 = ~37 miles

25%/3 = ~18 miles

Am I on the right track? Any suggestions?

Start by reading this thread: Better (reverse) SOC meter already in the car?
Then join the conversation there.

Ray

I did read it. Should I post this under that thread instead?

Since the temps don't change much in you neighborhood, 21kWh is a good standard at 100% charge, however, be aware that it decreases significantly with colder weather... minus the energy consumed by the heater.

Have you checked out this chart?

http://www.mynissanleaf.com/viewtopic.php?p=101293#p101293" onclick="window.open(this.href);return false;

Yes, in fact I have a copy in my car. It's great for when I'm not driving. I tried to come up with some simple calculations for when I'm driving. I tried it this morning using the avg miles/keg value. After about the 5th series, it got a lot easier to mentally calculate it. My value was always lower then the GoM value. I lose some accuracy when using the 'hours to chg' value, and I don't take into consideration other factors, such as climate control, temp, incline... It appears that my calculation is really only useful for determing initial est driving range based on my anticipated miles/kwh value, and keeping my mathmatical skills sharp while driving. If that is the case then TonyWilliams range table is much more accurate. I think i'll shrink Tony's graph and laminate it.

tjbrinson said:

I lose some accuracy when using the 'hours to chg' value, and I don't take into consideration other factors, such as climate control, temp, incline...

Click to expand...

Yes, Tony's chart is best, really easy to use, especially if you are starting out. There are couple of things you could try, but both of them will require some mental math.


The simplified method leveraging the charging time display will work with reasonable accuracy if your average fuel economy is around 4 m/kWh. Your true range will be underestimated by about 10% in this scenario.

If your energy economy was closer to 5 m/kWh, then the multiplier would be 4 instead of 3 miles ( 5 m/kWh x 0.8 kWh = 4 miles ). The idea is to determine your multiplier upfront using your energy economy. It's pretty simple, but hopefully accurate enough for your needs.

Another thing to remember: if you decide to give this method a try, then use the trickle charger only to top off to a 80% or 100% charge. Don't use it for small opportunity charges in the middle of the SOC range. The charging time display could lose its point of reference, and the readouts could be off. For example, we have seen 26, 27 and 28 hours on this display because of this effect.

Remember that 25 hours should be the maximum when charging from turtle to full. Alternatively, it's 21 from turtle to 80% charge. If you follow this rule, the charging time display will be a good gauge of your SOC.