Autonomous Mobile Robot Battery Runtime Calculator
The Autonomous Mobile Robot Battery Runtime Calculator estimates how long an AMR can operate from a battery before reaching a planned reserve level. It uses rated battery energy, average electrical power draw, a reserve percentage, and an overall usable-energy efficiency factor to estimate practical operating hours between charges or battery swaps.
The calculator is useful for early shift planning, charger sizing discussions, and comparisons between battery or duty-cycle assumptions. Average power draw should represent the robot’s typical mix of travel, payload handling, onboard computing, sensors, and idle states rather than only a motor’s peak rating. The reserve setting keeps a portion of rated energy unused, while the efficiency input can represent conversion losses and other reductions between rated battery capacity and energy actually available to the robot. Real runtime can change with payload, speed, floor conditions, temperature, battery age, route profile, accessory loads, and battery-management limits, so measured fleet data should replace estimates when available.
Battery and load inputs
kWh
kW
%
%
Result
—
Estimated operating runtime
Usable battery energy—
Energy held in reserve—
Estimated minutes—
1. Enter rated battery capacity Use the battery pack’s energy capacity in kilowatt-hours.
2. Set average robot power draw Use an average kilowatt load across the operating cycle rather than a short-duration peak.
3. Choose a reserve level Enter the percentage of rated battery capacity you plan not to use during normal operation.
4. Apply usable-energy efficiency Use this factor to account for conversion losses and practical energy that may not be fully available.
5. Review runtime Compare the estimated hours with shift length, charging windows, and operating requirements.
Runtime hours = [Battery capacity × (1 − Reserve) × Usable-energy efficiency] ÷ Average power draw
Reserve and efficiency are entered as percentages and converted to decimals. Battery capacity in kWh divided by power in kW produces time in hours.
The formula assumes average power draw remains representative over the modeled operating period and does not model changing battery voltage or state-dependent power use.
What the result means
The main result estimates operating hours available before the planned reserve is reached under the stated average load.
For production planning, validate the estimate against measured discharge data because payload, traffic, temperature, battery health, and route conditions can materially change runtime.
The robot is expected to operate for about 4 hours 56 minutes before reaching the planned reserve, assuming the average load remains representative.
Why use average power instead of peak power?
Peak power may occur only during acceleration, lifting, or another short event. Runtime depends on energy consumed over time, so a duty-cycle average is usually the more useful input.
What does the reserve percentage represent?
It is the portion of rated battery energy intentionally left unused in normal planning. A reserve can protect operational margin and avoid scheduling a robot to run all the way to zero indicated charge.
Can I use amp-hours instead of kilowatt-hours?
Not directly with this formula. Amp-hours must be converted to energy using the battery voltage and the appropriate electrical assumptions before entering kWh.
Why might an older battery run for less time?
Battery aging can reduce usable capacity and increase losses. Lower the effective capacity or efficiency input if measured battery health indicates less energy is available than the nameplate rating.
Does this estimate include charging time?
No. It estimates discharge runtime only. Charger power, charging curve, queueing, and the chosen state-of-charge window determine how long the robot must remain at a charger.