{"@context":"https://schema.org","@type":"Dataset","name":"HikingSpecs Physics Engine — Formula v1.0","version":"1.0.0","description":"Forensic physics model for outdoor wearable battery performance. Computes effective capacity (C_eff) under real-world thermal, wind, display, GPS-sampling, and battery-aging conditions. Reveals the Reality Gap between manufacturer marketing claims and physics-derived expected runtime.","license":"https://creativecommons.org/licenses/by/4.0/","creator":{"@type":"Organization","name":"HikingSpecs Lab","url":"https://hikingspecs.com"},"datePublished":"2026-05-10","keywords":["outdoor watch battery life","GPS watch cold weather performance","smartwatch battery degradation","Reality Gap","forensic physics","hiking watch comparison"],"measurementTechnique":"Physics-based modeling using calibrated chemistry, GPS-mode, display, and convective-cooling coefficients. Inputs validated against manufacturer datasheets and independent measured drain tests.","variableMeasured":[{"@type":"PropertyValue","name":"C_eff_mwh","description":"Effective battery capacity at scenario end, in milliwatt-hours."},{"@type":"PropertyValue","name":"reality_gap_pct","description":"Percentage difference between manufacturer-claimed GPS hours and physics-derived blackout ETA."},{"@type":"PropertyValue","name":"blackout_eta_h","description":"Hours from t=0 until C_eff reaches zero under the specified scenario."},{"@type":"PropertyValue","name":"T_case_c","description":"Effective case temperature at the battery cell, accounting for material-dependent convective cooling."},{"@type":"PropertyValue","name":"alpha_cycle","description":"Battery aging coefficient as a function of charge cycles and chemistry."}],"formula":{"expression":"C_eff = (C_nom · α_cycle · e^(-k · (T_ref - T_case))) - (Δt · (P_idle + P_gps + P_disp_adj + P_backlight))","components":{"C_nom":"Nominal battery capacity in mWh","α_cycle":"1 - (rate · n_cycles), floored at 0.60","k":"Chemistry-specific thermal exponent","T_ref":"Chemistry reference temperature in °C","T_case":"Case temperature: T_BODY + (T_amb - T_BODY) · coupling, where coupling = β/2 + (1 - β/2) · √(v/v_ref)","Δt":"Scenario duration in hours","P_idle":"Device baseline power in mW","P_gps":"GPS-mode-dependent power in mW","P_disp_adj":"Display power adjusted for sunlight (>50,000 LUX) per display type","P_backlight":"Backlight contribution averaged over duration"}},"constants":{"T_BODY_C":33,"V_REF_MS":10,"SUNLIGHT_LUX_THRESHOLD":50000,"CRITICAL_GAP_PCT":20,"MARGINAL_GAP_PCT":10,"ALPHA_CYCLE_FLOOR":0.6},"coefficients":"Per-chemistry thermal exponents (k), per-material case-cooling factors (β), per-mode GPS power draw, and per-display penalties are calibrated against datasheets and validated against independent field measurements. Specific values are proprietary. See /methodology for a worked validation (model within ~5% of independent field data).","riskClassification":{"SAFE":"reality_gap_pct <= 10","MARGINAL":"10 < reality_gap_pct <= 20","CRITICAL_FAILURE_RISK":"reality_gap_pct > 20"},"reproducibility":{"audit_hash":"SHA-256 of canonical(formula_version + dossier_id + scenario)","canonicalization":"JSON with sorted keys at every depth, no whitespace","guarantee":"Identical (formula_version, dossier_id, scenario) tuples produce byte-identical audit_hash and numerical outputs."},"citation":"HikingSpecs Lab. (2026). Forensic Physics Model for Outdoor Wearable Battery Performance, v1.0. https://hikingspecs.com/formula/v1.0"}