Power System Failures, Not Code Bugs, Are Often Behind Unstable Robot Performance

Robots that function correctly on a workbench frequently become unstable in real-world conditions, exhibiting random restarts, sensor errors, and communication failures. Engineers often blame software bugs, but the root cause is frequently the robot's power system struggling with rapidly shifting energy demands. Unlike simple electronics, robots can surge from low idle current to several amperes within milliseconds, particularly when motors accelerate, change direction, or carry heavier loads. This sudden current spike causes voltage sag — a temporary drop in battery voltage that can reset microcontrollers, disrupt sensors, and cut wireless links. Contributing factors include battery internal resistance, poor wiring connections, undersized cables, and cold temperatures, all of which worsen voltage instability under high-current conditions.