I have never kept the battery meter on miles of range because I don't know how they calculate the number and thus don't trust it. I keep the meter on percent SOC. So instead of watching the range vary seasonally, I watch Wh/mi of consumption vary seasonally. The capacity of the battery does not vary seasonally or with temperature, with one caveat I'll get to. You can figure out the capacity of your battery: use the trip meter, or even better the app on the v7.0 IP that resets automatically for each leg driven. Multiply miles driven for a leg by Wh/mi for the leg and divide by 1000 to get kWh consumed, and then divide by the change in % SOC between the beginning and end of the leg. So if you start to drive at 66% SOC, end at 57, drive 18.8 miles using 362 Wh/mi, which multiplies to 6.81 kWh, and divide by the .09 change in SOC, you get 76 kWh, which is what 100% capacity means for your pack (the numbers are from a drive I did yesterday). Because the SOC meter rounds to the nearest percent, the rounding errors throw off the result, so you have to average multiple legs. Measure each individual drive so the calculation isn't thrown off by vampire losses while parles.