Fluctuating and erratic estimated miles range

I'm not sure if this is the behavior of all Leaf's or just my Leaf. I've found the miles available on my dashboard erratic. For example, I fully charge my Leaf at work. I start car and see 100 Miles. I start driving home (10 miles) and after a few miles the dash indicates 85 miles. I've seen this repeatedly where the miles drop by 5-10 miles after just driving a few miles (no air conditioning, no extreme weather, etc). Is this normal behavior? Thanks.

Normal. Not a good thing, but normal for the Leaf. Count your bars on the dash for a more accurate reading of remaining miles.

kevinwang1 said:

I'm not sure if this is the behavior of all Leaf's or just my Leaf. I've found the miles available on my dashboard erratic. For example, I fully charge my Leaf at work. I start car and see 100 Miles. I start driving home (10 miles) and after a few miles the dash indicates 85 miles. I've seen this repeatedly where the miles drop by 5-10 miles after just driving a few miles (no air conditioning, no extreme weather, etc). Is this normal behavior? Thanks.

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You'll find many posts on the subject. It is "normal." Ignore it. After you get a feel for your car, the terrain, and the speeds you drive, you'll live by the number of bars you have remaining and the avg. miles per kWh. It's been my experience that terrain elevation and freeway speeds are the two wildcards in the estimates.

Nissan has already tweaked the calculation in the last firmware upgrade. A lot of people feel that the change made it less accurate with a full charge and more accurate when it approaches the bottom. I expect updates to occur again after more data is collected in real world driving conditions. Welcome to the world of Leaf v1.0

kevinwang1 said:

I'm not sure if this is the behavior of all Leaf's or just my Leaf. I've found the miles available on my dashboard erratic. For example, I fully charge my Leaf at work. I start car and see 100 Miles. I start driving home (10 miles) and after a few miles the dash indicates 85 miles. I've seen this repeatedly where the miles drop by 5-10 miles after just driving a few miles (no air conditioning, no extreme weather, etc). Is this normal behavior? Thanks.

Click to expand...

Try pulling away downhill with a tailwind at 35 mph and the miles will go up. Then try 70mph up a hill or into a strong wind and watch the miles plummet. What else would you expect?

kevinwang1 said:

I'm not sure if this is the behavior of all Leaf's or just my Leaf. I've found the miles available on my dashboard erratic. For example, I fully charge my Leaf at work. I start car and see 100 Miles.

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I got the car on July 1st, so still getting used to it. For me with a full charge it shows 93 miles (without A/C). Then as I am driving it goes all over the place, but never more than 93 miles.

Forget about getting accurate estimate out of Leaf even with SOC bars. Once you start commuting you'll get a feel of the Leaf's range for your drive.

If you look at other threads on the forum, you will commonly see the "miles remaining" referred to as the Guess-O-meter. The fundamental problem is that it is based on an algorithm that projects the mileage for the remainder of your trip based on some weighted function of the mileage over the last 5 to 10 miles (we are guessing, Nissan has not divulged the actual algorithm). So it will be accurate at any point if you turn around and retrace you last 10 miles at the same speed using the same heat or air conditioning settings. How often does that happen?
Read up on other threads on how to use the bars to estimate you remaining mileage and ignore the miles remaining numbers.
there is even a handy chart to reference.

BTW, here's another, current, discussion on whether anybody has seen a "remaining range" of more than 100 miles.

kevinwang1 said:

I'm not sure if this is the behavior of all Leaf's or just my Leaf. I've found the miles available on my dashboard erratic. For example, I fully charge my Leaf at work. I start car and see 100 Miles. I start driving home (10 miles) and after a few miles the dash indicates 85 miles. I've seen this repeatedly where the miles drop by 5-10 miles after just driving a few miles (no air conditioning, no extreme weather, etc). Is this normal behavior? Thanks.

Click to expand...

From http://www.leafic.com/wiki/index.php/MY2011_Driving_Range

"Range Indicator

In place of a fuel gauge, you have a range gauge which displays an estimate of the range left in the battery. Based on user's reports, the range estimate is based heavily on your previous driving conditions. This means that if you just went 30 miles on the highway and your range says your have 20 miles left, it is estimating you have 20 highway miles left. If you then drove around town instead of the highway, you would get more than 20 miles range. While getting more range than indicated is not particularly an issue, if you drove around town first, then got on the highway, your actual range would be less than indicated when getting on the highway.

This has brought criticism from drivers with the argument that a true SOC gauge would be more useful as only the driver knows what type of driving they will be doing. Drivers would learn, just as they do with a conventional fuel gauge, how far they could go based on how much energy is truly left in the battery."

it's just not possible to create an accurate estimation of range so the car's computer is constantly recalculating based on recent performance, which will very quite a lot unless you drive on level ground, the same speed and same ambient temperature each day. Folks who have MPG estimators on their car will be familiar with how much this can all vary. With a gas car, the tank is so large, we just don't have to pay attention to range down to the last mile but if you did, you'd see the number vacillate a lot as well. My understanding also is that the computer makes it's calculations based on floating voltage, which is, at best a estimate of the amount of electricity remaining. From what I've gathered so far, measuring charge left in a battery is much different than actually getting a reading of the level of gas left in an ICE vehicle's tank, there is no way to accurately measure the true amount of electricity left in a battery on the fly. the calculator does seem to get more accurate the closer you get to the end of the charge. I believe this is true because the computer is projecting the effect of current driving habits and conditions over a shorter and shorter distance (as miles left declines).

You hear many complaints about this system, but I have to say I find it valuable in letting me know how my current and most recent driving is effecting overall efficiency, if it drops a lot, it's usually because I'm going up hill or because I'm "letting loose" a bit with the accelerator or cranking the heater. I find it a good indicator of how efficient I'm being, which is helpful when I'm going far enough between charges that I have to pay attention to range to make sure I don't run out too soon. I do not expect the range indicated at the beginning of the drive to relate closely to what I will get out of the full charge, but I find the fluctuations while I'm driving to be helpful somewhat, to motivating me to using range maximizing techniques when I need to.

g

GaslessInSeattle said:

From what I've gathered so far, measuring charge left in a battery is much different than actually getting a reading of the level of gas left in an ICE vehicle's tank, there is no way to accurately measure the true amount of electricity left in a battery on the fly.

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Its easy to measure how many kwh are left in the tank, but again its next to useless to predict the remaining range.. the computer has no idea what you will do next. When the Leaf arrives in flat states with sane hwy speeds you will have less complaints about range prediction.

kevinwang1 said:

I'm not sure if this is the behavior of all Leaf's or just my Leaf. I've found the miles available on my dashboard erratic. For example, I fully charge my Leaf at work. I start car and see 100 Miles. I start driving home (10 miles) and after a few miles the dash indicates 85 miles. I've seen this repeatedly where the miles drop by 5-10 miles after just driving a few miles (no air conditioning, no extreme weather, etc). Is this normal behavior? Thanks.

Click to expand...

Even with ideal weather conditions and not use the A/C, heat or even the fan, the terrain your driving can make a huge difference. Even if it doesn't look it to your perspection and not noticing the long gradual incline, and your dots are just a few in usage you can be holding at a range that hasn't change immediately because sometimes it takes a minute for the re-calculation to catch up and then boom, it catches up and you lost a significant amount of range. This to me seems typical for the Leaf's behavior. The calculations are never dead on. It does it's best.

GaslessInSeattle said:

You hear many complaints about this system, but I have to say I find it valuable in letting me know how my current and most recent driving is effecting overall efficiency

Click to expand...

+1

In the morning I reset the trip odometer and note the estimated range in D and in ECO, and figure I'll get something in between those numbers. By the time I get to the bottom of the hill the est range is way up but I don't count on it. By the time I get off the highway the est range is way down but I don't worry about it. Sometime later the sum of odometer plus estimated range is usually back in between my original D and ECO numbers. At the end of the day I watch the estimated range creep down as I ascend the hill, to settle usually just where the morning numbers predicted.

Check out the "Range Estimate" link in my signature: