Formula
The reserve is a share of the range you do not plan to use:
miles = kWh × miles per kWh × (1 − reserve)
The charging cost page prices a distance. This page answers how far the pack can go. A health and buffer adjustment is the EV battery page.
Assumptions
- The capacity is already the usable figure.
- Efficiency stays constant.
- The reserve is a percent of range, not a time of day.
Worked example
75 kWh at 3.5 miles per kWh, keeping a 10% reserve, gives a range of 236.25 mi.
Input definitions
- Usable capacity
- Kilowatt-hours you are willing to spend. Use the EV battery page if you still need to apply health and a buffer.
- Reserve
- The percent of range left unused.
Limitations
Cold weather, speed, and hills change miles per kilowatt-hour. This is not a route planner.
Questions
What if the pack is not new?
Reduce the kilowatt-hours first. The EV battery page multiplies nameplate capacity by health and a buffer.
Why keep a reserve?
So the estimate does not end at an empty pack. Ten percent leaves a tenth of the range unused.