Battery Life Estimator (UAV)

Predict remaining flight time under current load and wind using a simple empirical model you can calibrate from 5–10 past flights.

What it does

• Calibrate a model from your flight logs (payload, speed, wind, flight time).
• Estimate total flight time for a given payload & airspeed.
• Estimate remaining time based on current pack voltage (via a LiPo voltage→SOC curve).

Model (MVP)

We fit a linear model on the inverse of total flight time (minutes):

1 / T ≈ b0 + b1 * payload_kg + b2 * v_air^2

where v_air = ground_speed_mps + headwind_mps (tailwind is negative).

Then we estimate remaining time as:

T_remaining ≈ T_total * SOC(voltage_per_cell)

SOC is mapped from an industry-typical LiPo 3.3–4.2 V per cell curve (see code).

This is deliberately simple, fast, and explainable. You can later add more features (temperature, altitude, prop type) or non-linear terms.

Quick start

1. Put your flights into a CSV with columns:

   • flight_time_min – total flight time (minutes)
   • payload_kg
   • ground_speed_mps
   • headwind_mps – positive=headwind, negative=tailwind

2. Calibrate and save a model:

python battery_life_estimator.py calibrate --csv example_flights.csv --out model.json

3. Estimate total flight time for a new config:

python battery_life_estimator.py estimate-total --model model.json   --payload-kg 0.6 --ground-speed-mps 10 --headwind-mps 2

4. Estimate remaining time using current voltage (per-cell):

python battery_life_estimator.py estimate-remaining --model model.json   --payload-kg 0.6 --ground-speed-mps 10 --headwind-mps 2   --voltage-per-cell 3.85

Example data

See example_flights.csv for a fake-but-plausible dataset to test the pipeline.

Notes

• Voltage→SOC mapping uses a smoothed interpolation of typical LiPo discharge (4.20V=100%, ~3.50V≈20%, 3.30V≈0%). Always set your own conservative landing threshold.
• The model assumes steady-state cruise. Hover-heavy profiles or aggressive maneuvers will deviate.
• For quads, v_air^2 works well as a first-order proxy; for fixed-wing you may want lift/drag terms and throttle% if available.

License

MIT