Ford Explores more accurate EV range calculations

[jmueller065]

Now this could be interesting:

Ford Explores more accurate method for predicting EV range

 

[unplugged]

Here is a perfect example of how the range can completely fail. I drove the FFE from Murietta, CA to Palm Springs this last weekend. I took a route that brought me through the mountains and down to Palm Desert. My range to begin with gave me negative 7 miles for the 87 mile trip. Not to worry, because I had charging station alternatives. I calculated the mountain road peak by using Google Earth and set a waypoint at that location. This was 50 miles of gradual 3,000 feet up-slope, so I figured I could at least go 50 miles on a full charge. Then, I would have 4,000+ feet of downhill to recharge the battery.

My manual calculation was frighteningly close, but I knew exactly when the downhill began, so I didn't worry when the remaining miles showed 6 close to the peak. Once I started downhill, the craziness began. Eventually, I showed 558 miles of range remaining when I got to the bottom. I made it to the hotel with the EV station with 17 miles left. I think it was more like 10, but it was a comfortable amount. My regen braking showed 156 miles. Unfortunately, the MFM website threw out my record. (Why doesn't it do that for those EV mileage record holders at 250 miles?) It took days for the range to fix itself. When I got in the car the next day, my range showed 185 or so.

From then on, I noticed that steep mountain driving would doom the range calculation. Fortunately, I have become pretty adept at using the battery indicator alone and can usually ignore the estimate.

The lesson here is that mountain or hilly driving will destroy any semblance of reality for the range estimate. Flat constant speed is about the only way to get an accurate identity of what range you truly will get.

 

[v_traveller]

I deal with this inaccuracy every day since my commute involves a couple of significant (1000ft+) freeway elevation gains and losses, thankfully they all even out after a round trip to about 80 miles of range.

Just did a really quick patent search, I think we might be stuck with inaccuracies for a while, thanks to at least one individual that laid a specific claim to range calculators that use "external" sensor data (i.e. GPS, weather info, time of day, speed limits) to determine range. Altitude, weather, traffic, and speed limit data along the planned route would result, in my opinion, to accurate range predictions.

So unless Ford bought the rights or can prove they invented this prior to the filing date of such patents, we are probably stuck with the wonderful guess-o-meter for a while.

 

[jmueller065]

Seems to me that if they would just use a rolling average of your Wh/mile for something longer--like the past week or so--then the GOM would be less prone to jumping around and more accurate to your style of driving.

Sure it wouldn't be accurate if you decided to drive 70 miles on a 25mph road when you usually drive the freeway but that really is a corner case. I think most people would be happy if it was a reasonable number that didn't jump all over the place all the time every time you drive slowly, or punch the accelerator.

Even better it would be nice to be able to pick what you want displayed on top of the battery: range to empty, percent charge remaining, kWh used, etc. Personally if it showed % to empty (much like, say, an ICE car! LOL) I'd be perfectly happy with that.