Also in: Disaster Response and Recovery
Battery Runtime
Hours of runtime from Ah, voltage, depth of discharge, and load (optional Peukert).
Example
You enter
- Battery capacity (Ah) 100
- System voltage (V) 12
- Depth of discharge (%) 80
- Load (W) 120
- Peukert exponent k (1 if unknown) 1
You get
- Runtime (hours) 8 hr
- Runtime (minutes) 480 min
- Usable energy 960 Wh
Checked against published worked examples from: SmartGauge Electronics.
Details, formula, and sources
Formula or tableRuntime = (battery_Wh × inverter_efficiency × depth_of_discharge) / load_W. Coulombic adjustments via Peukert exponent for lead-acid only.
Source and editionBattery-chemistry physical facts; manufacturer datasheets by name.
Free accessDatasheets free on each manufacturer site.
What governsEstimate. AHJ and licensed electrician govern. Verify against the NEC edition adopted in your jurisdiction.
API field namesamp_hours, system_V, dod_percent, load_W, peukert_k, hours, minutes, usable_Wh
- Inverter efficiency 100% (DC / ideal) unless user supplies; enter ~90% for an AC load through an inverterengineering practice
- DoD limit user-supplied depth of discharge (default 100%); typical practice is 80% LFP / 50% lead-acidmanufacturer typical