I built this because most battery runtime calculators average current and ignore impedance, which often leads to optimistic results and unexpected brownouts.

The tool separates:

Runtime (energy): analytic (Q/I or E/P) using event-based duty cycle

Brownout (voltage): SOC sweep with impedance snapshots (idle / TX / optional peak using RC²+L)

Uncertainty: Monte Carlo (capacity/DCIR/temp/aging)

For the public demo, uncertainty sampling is intentionally limited (fixed temp/age, runtime distribution from capacity/DCIR). Full uncertainty plots are available in developer mode.

Feedback welcome, especially on whether this separation matches real-world failure modes you’ve seen.