Battery runtime planner
Estimate battery runtime from entered energy and actual load assumptions. Output compatibility remains unverified.
No account. No saved profile. Inputs reset when you leave or refresh.
Estimate stored battery energy divided by average load. No battery capacity, generic fridge load, duty cycle or loss factor is preselected. Output compatibility is not verified by runtime.
Your runtime estimate
Enter the active fields to calculate. Inputs stay in this page and do not update readiness or inventory.
Assumptions, output limits and sources
- Energy capacity does not confirm that a battery can start or continuously run the appliance. Check manufacturer continuous output, starting surge and surge duration, voltage, frequency and outlet compatibility.
- Fridge running watts, duty cycle and starting surge are different. Surge is not a continuous load. Simple cycling mode does not model defrost, variable-speed compressors or extra start energy unless captured in measurements; measured daily energy is preferable.
- Assumes the entered energy budget is available at the start, no charging during use and a stable average load. Reduce entered energy for partial charge; do not deduct the same reserve twice.
- Age, temperature, load-dependent efficiency, inverter self-consumption, cutoff and actual usable capacity can change runtime. There is no universal loss percentage or real-world guarantee.
- Not certification for critical medical backup, food safety, wiring or system sizing. Runtime does not establish safe refrigeration temperature.
Conversion: Wh = Ah × nominal V, or mAh ÷ 1000 × nominal V. Average W = daily Wh ÷ 24, or running W × running fraction + off-cycle W × remaining fraction. W × hours = Wh.
Assumptions and sources
Energy capacity does not confirm that a battery can start or continuously run the appliance. Check manufacturer continuous output, starting surge and surge duration, voltage, frequency and outlet compatibility.
Fridge running watts, duty cycle and starting surge are different. Surge is not a continuous load. Simple cycling mode does not model defrost, variable-speed compressors or extra start energy unless captured in measurements; measured daily energy is preferable.
Assumes the entered energy budget is available at the start, no charging during use and a stable average load. Reduce entered energy for partial charge; do not deduct the same reserve twice.
Age, temperature, load-dependent efficiency, inverter self-consumption, cutoff and actual usable capacity can change runtime. There is no universal loss percentage or real-world guarantee.
Not certification for critical medical backup, food safety, wiring or system sizing. Runtime does not establish safe refrigeration temperature.
FAA — battery capacity conversion: https://www.faa.gov/hazmat/packsafe/airline-passengers-and-batteries
Virginia Cooperative Extension — appliance energy use: https://www.pubs.ext.vt.edu/2901/2901-9014/2901-9014.html
Goal Zero — output capacity and surge: https://help.goalzero.com/hc/en-us/articles/39082100367003-WHAT-CAN-A-YETI-POWER
Use this as a starting point
Runtime is an energy-budget estimate under your entered assumptions. It does not verify starting surge, output power, voltage or appliance safety. Refer to the planner’s source-linked assumptions and manufacturer data.
Return paths and next tools
This tool: /prepare/battery-runtime
Tools hub: /prepare
Combined overview: /prepare/household-overview
Water stocktake: /prepare/water-calculator
Food stocktake: /prepare/food-stocktake
Planning kit: /prepare/kit-builder
Battery runtime: /prepare/battery-runtime
Household plan: /prepare/household-plan
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