GaslessInSeattle said:
People get discouraged from using the GOM because of the wild fluctuations at the upper end of the charge, but it gets better and better toward the end, taking into account a myriad of factors, a variety of factors I can't not accurately factor using the charts unless i'm in very consistent driving conditions.
This an interesting and astute observation. I was going to bring it up in another thread, but it might be better to expand on the topic here. Although I'm still suspicious of the GOM, for reasons I will explain later, I found it to be quite accurate when the battery gauge is between 2 and 7 bars. I would not recommend using it outside of this range.
As a positive example, please have a look at the first three images below. After much handwringing, I came up with a range estimate of 44 miles. Guess how much the GOM is showing: 41 miles. This was hardly worth all the effort! Or was it?
I did extensive testing in predictable conditions and with consistent driving, and I can attest that the GOM is not accurate at high SOC. I'm unable to offer a reasonable explanation for this behavior, since I can usually ballpark my total range more accurately using simple methods, and without having access to all the good information that's flying over the CAN bus.
Be it as it may, it looks like I will complete this test drive after approximately 90 miles. That was easy to predict, since our weather has been consistent and I've been consistently getting energy economy figures between 4.2 to 4.5 m/kWh for over a month now. I'm estimating my current available battery capacity to be 20.5 kWh, based on several metrics collected over the course of a month or so as well. And I drive on flat roads.
So how is possible then, that the GOM gave me a range estimate of 118 miles after a full charge 48 hours ago? That's 30% more than my actual will be for this charge, and it does not correlate with my last few trips either. I would consider this to be very inaccurate, and I have seen this behavior very consistently. The GOM fails to deliver on what should be an easy estimate. Wonder if others have as well?