@TimothyHW3 I'm confused.... if I take the range displayed and divide it by the percent battery remaining, I get the same number as when I actually charge to 100%
As far as I can tell, Stats uses three digits of precision for the % internally when projecting the full range. So from that perspective it seems like this method would be reasonably accurate. Assuming Stats is using the “right” calculation for SoC of course.
This projection/extrapolation method for full miles has better accuracy the higher the SoC %. That is one issue with that method. But as long as you only pay close attention to the number when your charge is above 50%, the precision error won’t be inflated too much. Once your rated miles drop below 100, for example, you only have two significant figures, so you can only say what your 100% range is within 10 miles or so.
Other than that, this method is pretty much equivalent to reading back the “fullkWh” from SMT or whatever.
However, with all of these methods, without charging to 100%, you are susceptible to BMS “confusion.” The BMS might be inaccurate in its estimate of what “fullkWh” is until you charge to 100%. There is not a way to know until you get to 100%.
Even if you do that, it may still be inaccurate until you discharge the battery to near 0% and then recharge it. How much error there could be there, I do not know. I only routinely discharge to 5-10% or so and I’ve never seen any significant adjustments after doing that.
As you say, I too have always found the projections of miles to be fairly accurate, and once you know the vehicle charging constant you can always calculate what a CAN bus reader would tell you within about 0.5%, without actually having one. The CAN bus reader doesn’t provide significant additional information on battery capacity - though it does provide a lot of other information of course. Just saying you don’t need one to be able to say what your fullkWh is - the screen in your car effectively tells you that. Can see that earlier in this thread, where we were able to figure out your battery capacity and your approximate buffer size before you received your CAN bus reader.