This calculator estimates how long an agricultural robot can operate from its usable battery energy at a stated average electrical load. It can support field scheduling, charging-station planning, battery-swap decisions, and comparisons between operating modes before a deployment plan is finalized.
Runtime depends on average power, not only battery nameplate capacity. Traction on soft soil or slopes, implements, pumps, compute hardware, environmental controls, communications, and other auxiliary loads can materially change consumption. The reserve input leaves part of the battery unused rather than assuming a full discharge to zero. The result is an energy-balance estimate under steady average conditions; battery age, temperature, power spikes, inverter efficiency, state-of-charge calibration, and manufacturer protection limits can cause actual runtime to differ. For planning, use measured average power from representative field work whenever available.
Battery and power assumptions
kWh
kW
%
kW
Result
—
estimated operating runtime
Energy available for operation—
Total average power—
Runtime in minutes—
1. Enter usable battery energy Use the battery energy available to the system in kilowatt-hours, preferably after manufacturer limits rather than raw cell capacity.
2. Enter average operating power Use the average kilowatt draw for driving and the primary task under representative conditions.
3. Set a battery reserve Enter the percentage of battery energy you intend to leave unused before charging or swapping.
4. Add auxiliary load Include additional average electrical loads not already captured in the operating-power figure.
5. Review runtime Compare hours, minutes, usable energy, and total average power in the result panel.
Usable operating energy = Battery energy × (1 − Reserve %)
Total average power = Average operating power + Auxiliary load
Runtime (hours) = Usable operating energy ÷ Total average power
Kilowatt-hours divided by kilowatts gives hours. The model assumes the entered power values represent a stable average over the operating period.
What the result means
The main result estimates operating hours before the selected reserve threshold is reached.
High-load implements, difficult terrain, temperature, and battery degradation can reduce actual runtime, so operational plans often include a conservative buffer.
Given:
Usable battery energy: 22 kWh
Average operating power: 3.6 kW
Battery reserve: 20%
Auxiliary load: 0.6 kW
Calculation:
Operating energy = 22 × (1 − 0.20) = 17.6 kWh. Total power = 3.6 + 0.6 = 4.2 kW. Runtime = 17.6 ÷ 4.2 = 4.1905 hours.
Result: About 4.19 hours, or 251 minutes.
Interpretation: The robot would be expected to reach the 20% reserve after a little over four hours if average load stays near 4.2 kW.
Should I enter nameplate battery capacity or usable capacity?
Use usable energy if it is known. If you only have nameplate capacity, make sure the reserve and any manufacturer-imposed state-of-charge limits are represented conservatively.
Does the reserve percentage represent battery left at shutdown?
Yes. A 20% reserve means the calculation allocates only 80% of the entered battery energy to the operating period.
Why does terrain affect battery runtime?
Soft ground, slopes, mud, and frequent acceleration can raise traction power. When average power rises, the same battery energy is consumed in less time.
Can auxiliary power be left at zero?
Yes, if your average operating-power measurement already includes all meaningful electrical loads. Otherwise enter the separate average load for pumps, sensors, compute equipment, or attachments.
Does this predict battery life over years?
No. This calculator estimates runtime per charge. Long-term battery aging depends on chemistry, cycle depth, temperature, charge rate, storage state of charge, and other factors not modeled here.