Meritime Intelligent Drone Sim

Each band is battery-side electrical power — drivetrain losses are folded into the propulsion bands proportionally, so the stack sums to the pack draw. The dip is real: in forward flight the rotors meet undisturbed air, so induced power falls faster than body drag rises.

One flight, end to end. Climb and descent energy come off the top, your time on station is protected next, and whatever is left buys transit — which the out-and-back formula turns into a radius. Drop the airspeed to zero and the transit legs vanish, leaving a pure hover mission: the same profile, degenerated.

A bigger pack carries more energy and more weight. The worksheet holds motor current at 3.25 A regardless of mass, so it shows endurance rising in a straight line with capacity. With the feedback restored the curve bends over hard: the first 5 Ah past the fitted pack buys about 4 minutes, the next 5 buys 2, and past 30 Ah you are adding kilograms for seconds. The mathematical peak does exist, but it sits at an all-up mass this airframe cannot lift — the thrust margin runs out first, which is the constraint that should actually size the pack.

Payload is not free and it is not linear either. Every gram must be held up by the same rotors, and hover power grows as mass^1.5. The curve is steepest at the left, so the first grams are the expensive ones: on the stock build the first 100 g costs about 0.6 min, while the 100 g after 2 kg costs barely 0.2 — by then there is not much endurance left to lose. The wall on the right is thrust margin, not energy: past it the aircraft still has battery but no longer has the authority to fly safely.