Plan AMR charging around the work, not the battery headline
Build a charger-time and robot-time budget, expose missing charging windows and agree the operating evidence before sizing an AMR deployment.
The buyer question is about replenishment
A robot can have enough battery capacity for an attractive demonstration and still lack a workable charging schedule for production. The question is not simply how long it runs. It is whether each robot can replenish the energy used by the planned work, within the available time, without taking essential transport capacity away when operations need it.
RobotAtom recommends two separate planning checks: a shared charger-time budget and a per-robot time budget. They expose different problems. Additional chargers cannot rescue a robot whose own work, charging and docking already exceed the operating window. Conversely, individually feasible robots can compete for too little shared charging capacity. Neither check replaces a time-resolved fleet simulation or a site trial.
Keep manufacturer values attached to their conditions
MiR's current MiR250 specification distinguishes active operation with maximum payload from no-payload operation and standby. It also qualifies its charging ratio as an upper-bound claim and warns that local conditions and application setup can change specifications. A headline runtime is therefore not a universal productive-time assumption. Record the exact configuration and operating conditions supplied for your project.
OTTO's charging explanation, published on 15 December 2025, describes its fleet manager sending robots to charge between jobs. Its stated charging times use a 10-to-90-percent band and differ by model. Those are manufacturer descriptions, not RobotAtom performance measurements. Do not combine a runtime from one battery band with a charging duration from another and treat the result as a proven duty cycle.
Write down one comparable set of inputs
For an initial budget, group robots with comparable duties and batteries. Define the repeated daily operating window, required productive hours per robot, productive runtime between the agreed charge limits, recharge time for that same interval, off-task travel and docking, compatible charger count and usable hours per charger. Keep battery reserve inside the agreed runtime assumption rather than applying an unexplained percentage twice.
Ask where each number comes from: a measured route, a provider estimate, a specification or an illustrative assumption. Preserve that distinction in the project brief. If charging access is restricted during a cleaning window or an area closure, reduce the available charger window. If the demand has a sharp peak, keep its timing separately; daily averages do not show whether a robot is available at that peak.
Run the two arithmetic checks
Our charging-window calculator uses a steady-state budget. Multiply fleet size by productive hours per robot, then divide by productive runtime per recharge interval. This gives average recharge equivalents. Multiply by the matching charge duration to obtain charger-hours required. Compare that with compatible chargers multiplied by usable hours per charger. The rounded-up charger count is only an arithmetic lower bound.
Then calculate time per robot: productive hours plus its recharge equivalents multiplied by charging time and off-task docking time. Compare that total with the robot's operating window. This second check matters because charger capacity and robot availability are not interchangeable. Fractional recharge equivalents are an average across repeated days; the model does not claim to schedule partial visits or simulate battery state.
An illustrative calculation—not a fleet recommendation
Suppose eight robots each need 12 productive hours in a 16-hour window. Assume six productive hours between recharge intervals, one hour to replenish that interval and ten minutes of off-task travel and docking. The fleet needs 16 average recharge equivalents and 16 charger-hours. Two chargers available for 16 hours provide 32 charger-hours. Each robot uses about 14.3 hours for work, charging and docking.
Those invented teaching inputs show no average time deficit, but do not prove the fleet can meet a real schedule. If both chargers become inaccessible together, or robots require replenishment during the same demand peak, the averages hide the constraint. The calculator deliberately reports open scheduling questions instead of a green deployment-ready score. Change the inputs to see which assumption creates the deficit.
Turn the budget into an acceptance conversation
The next step is a time-stamped operating test with the responsible provider: representative loads, the intended charge band, the busiest work window and the actual route to the charger. Record work demand, charging starts and finishes, docking delays, queue time and unmet tasks. Agree beforehand what happens when a charger is unavailable and who reviews the resulting capacity shortfall. Do not alter safety functions to achieve a timetable.
For adopters, this makes infrastructure and scheduling assumptions visible before rollout. For providers, it replaces an open-ended battery question with a workload they can engineer against. RobotAtom brings the work, constraints and acceptance evidence into the complete solution. Use the free calculator to export your assumptions, then discuss the result with your operations and delivery team. Electrical design, safe installation and final fleet sizing remain specialist engineering decisions.
Sources
Material claims were reviewed against the following primary sources. External links open the publisher's website.
This article provides general information. A robotics project still requires site-specific engineering, safety and regulatory review.