INTERACTIVE TOOL // BACKUP POWER
Backup Power Calculator
Battery marketing talks in watt-hours. Your blackout happens in devices, hours and priorities. Add the loads you actually intend to run and turn them into a realistic energy target.
SCENARIO: Grid operators have isolated automated control systems after a suspected hostile AI incident. Restoration has no reliable timetable. Every percentage point on every battery now has a job.
Build your power load
Your power result
Add the devices you actually need during an outage, then calculate.
The calculation in plain English
Energy is estimated as device watts multiplied by hours of use multiplied by quantity. The calculator totals those watt-hours for one day, multiplies by the number of days you entered, then divides by your selected system efficiency. That final step accounts for losses in the battery, inverter and conversion process. It is deliberately a planning estimate rather than a promise of exact runtime.
For example, a 12-watt router used for eight hours consumes roughly 96 watt-hours. A 60-watt laptop used for three hours consumes about 180 watt-hours. Add phones, lights and a radio and the total can climb quickly. The useful lesson is often not “buy a bigger battery”; it is “run fewer things for less time.”
Capacity is not the same as power
A battery can have enough stored energy in watt-hours but still be unable to run a high-power appliance. Inverter output is measured in watts and must handle the loads operating at the same time, including start-up surges for some motors and compressors. This calculator shows an indicative “all listed loads at once” wattage with 25% headroom, but you must still check the continuous and surge ratings published by the equipment manufacturer.
Do not use this generic calculator to size backup for life-sustaining medical equipment. If someone depends on powered medical equipment, make a continuity plan with the clinical team and equipment supplier. UK Prepare explicitly recommends doing this before a power cut and keeping backup batteries charged where supplied.
AI doomsday scenario: ration the electrons
In the fictional endgame, the first night feels deceptively manageable. Phones are charged. The fridge is cold. A power station hums in the corner. Then the outage continues. Every always-on device becomes a leak. The router draws power even when the internet upstream is dead. A laptop burns an hour of battery displaying conflicting news. Someone plugs in a kettle and discovers the inverter cannot support it.
That is why the tool focuses on load discipline. Communications, safe lighting and essential equipment usually deserve priority over comfort loads. A smaller battery used intelligently can outperform a larger one that spends the first night powering everything as if the grid were coming back at breakfast.
How to make the estimate useful
Read the labels on your actual devices or use a plug-in power meter rather than trusting generic internet figures. Many devices vary dramatically with brightness, load, temperature and charging state. Put conservative values into the tool, then test your real backup system before an emergency. Run the devices, time the discharge and compare the result with the estimate.
Also plan charging. A battery is only a buffer unless you have a safe way to replenish it. Solar can extend endurance, but output varies with panel size, weather, season, orientation and daylight. Generators introduce fuel, ventilation and carbon-monoxide hazards and must never be used indoors or in an enclosed space. The safest plan is one you have physically tested under normal conditions.
Continue from here
Build this topic into a wider plan, then see how the same dependency could fail in an AI-collapse scenario.