Battery Runtime & Life Cycle Calculator (LiFePO4, AGM, UPS)
Calculate battery discharge runtime, usable watt-hours, and lifecycle longevity under inverter loads.
Input Parameters
e.g. 100Ah 12V lithium deep-cycle battery
12V, 24V, or 48V battery bank
e.g. 60W portable 12V fridge, 150W TV/lighting, 1000W microwave
DC to 240V AC pure sine wave inverters operate at 85% to 92% efficiency
Calculation Results
Visual Growth Breakdown
Formula & How Battery Runtime & Life Cycle Calculator (LiFePO4, AGM, UPS) Works
Battery runtime is a function of total stored energy (Watt-hours = Amp-hours × Volts) multiplied by the allowable Depth of Discharge (DoD). Lead-acid batteries must not be discharged below 50% DoD to prevent permanent sulfation damage, whereas LiFePO4 lithium batteries safely deliver 85–90% of their rated capacity across thousands of cycles.
- Enter Battery Capacity Rating (Ah) (Ah): Input your target parameter value.
- Enter Nominal Battery Voltage (V) (Volts): Input your target parameter value.
- Enter Continuous Load (Watts) (W): Input your target parameter value.
- Enter Battery Chemistry Type: Input your target parameter value.
- Enter Inverter Efficiency (%) (%): Input your target parameter value.
- Apply Formula: Calculate using
Usable Wh = (Ah × V) × DoD% | Total Load = Watts ÷ Inverter Eff | Runtime = Usable Wh ÷ Total Load. - Review Results: View exact computed answers, metrics, and worked mathematical proofs.
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Frequently Asked Questions (FAQs)
How long will a 100Ah 12V battery run a 200W load?
A 100Ah 12V LiFePO4 battery (90% DoD = 1,080 Wh usable) running a 200W AC load through a 90% efficient inverter (222W draw) will run for approximately 4.8 to 5.0 hours. An AGM battery (50% DoD = 600 Wh usable) will last only ~2.7 hours.
Why does lead-acid AGM last shorter than Lithium LiFePO4?
Lead-acid batteries suffer from Peukert's Law (capacity drops drastically under heavy loads) and cannot be discharged past 50% without shortening their lifespan. Lithium batteries maintain stable voltage output down to 90% discharge.
Authoritative Standards & Verified Reference Citations
Calculations and mathematical logic on this page are grounded in published statutory rules, regulatory standards, and official government data published by the following bodies:
Australian Standards including AS/NZS 3000 (Wiring Rules), AS 3600 (Concrete Structures), and AS 4100 (Steel Structures).
Accreditation and technical guidelines for civil, structural, mechanical, and electrical engineering.
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