Research — Illustrative (draft, unvalidated)
Charge/discharge cycle on a timeline
The battery starts full, discharges to the floor you choose, then recharges. Scrub the cursor along the timeline: the top chart is power (discharge above zero, charge below), the lower chart is state of charge, and the bar underneath is what the round trip loses. Durations are the harness's energy-over-power results, capped at the C-rate limit.
Power and state of charge against time, one full cycle
Example battery
Time into the cycle
Discharge down to
C-rate
Depth of discharge
Round-trip efficiency
Cycle status
Durations
Applied power
Round-trip loss
How the check read it
Client-side port:the logic and table in this page are a TypeScript port of the harness function, checked against values exported from the Python tests. Not a live API call. Module maturity, quoted from the harness repo: “Draft/unreviewed as of 2026-08-12 — no human domain-expert (power/storage systems engineer) has reviewed this code” (KICKOFF.md); VALIDATION.md calls its own pre-review “not a human SME sign-off.” The README says the functions are validated against the Tesla Powerwall 2 and Megapack 2 XL datasheets: the Megapack's 4-Hour and 2-Hour durations come out at exactly 4.00 h and 2.00 h, and the Powerwall usable-energy case is correct but trivial (100% depth of discharge of the usable figure). Example batteries are read from the harness's standards/ files; the Megapack datasheet publishes no depth of discharge, so 100% is assumed there. The straight lines between the harness's state-of-charge readings reflect constant power, which is this page's drawing choice.Real functions this maps to:
calculate_discharge_duration, calculate_charge_duration, calculate_state_of_charge, calculate_round_trip_efficiency_loss, calculate_usable_energy, calculate_c_rate_power_limit.Not modeled: degradation or cycle-life fade, thermal derating, temperature effects on the rated numbers, voltage sag at high C-rate, taper or constant-voltage charging (power is flat for the whole leg), dispatch economics or EMS scheduling, and inverter kVA limits. The round-trip loss is reported for the recharge energy but is not applied to the stored energy or the durations, because the harness functions do not do that either.See also:Charge/discharge cycle, auto demo · Battery dispatch, interactive