BackupHours

About this app

What BackupHours does

When the power goes out, the only question that matters is: how long until the fridge dies? BackupHours answers it in seconds. BackupHours is an offline runtime planner for anyone with a home battery, solar setup, EV with vehicle-to-home, or a fuel generator. Instead of vague marketing numbers like "backup for your home," you build a real list of YOUR appliances and circuits — fridge, chest freezer, well pump, sump pump, CPAP, router, space heater, medical devices — each with its wattage and how many hours a day it actually runs. BackupHours then calculates exactly how many hours (or days) your stored energy will carry that load, accounting for inverter efficiency and battery depth-of-discharge. The magic is load-shedding. Tag each circuit as Critical, Important, or Optional, then watch your runtime stretch as you shed the optional loads. See at a glance that running everything gives you 9 hours, but dropping the space heater and dryer buys you three full days on just the essentials. Build outage scenarios ahead of time — a 12-hour storm, a 3-day grid failure — so the plan is already made before you ever need it. Model any energy source: a 13.5 kWh home battery, a stackable solar-plus-storage system, a 77 kWh EV battery feeding the house through V2H, or a 4,000-watt generator with a known fuel burn rate. Generators get fuel-aware runtime so you know how many gallons stand between you and a dead fridge. Solar users can add a daily recharge estimate to model multi-day off-grid resilience. Because an outage is exactly when the internet is gone, BackupHours is built offline-first. No account, no login, no cloud, no subscription nagging you during an emergency. Everything you enter lives on this device. Open the app in a blackout and your whole plan is right there, instantly. BackupHours is for the people who plan ahead. Maybe you live where the grid is shaky, where wildfire shutoffs or hurricane season are a yearly reality, or where you just installed a shiny new battery and want to know what it can really do. Maybe you rely on a CPAP, a fridge full of insulin, a sump pump that keeps the basement dry, or a well pump that is the only thing standing between you and no running water. For you, "how many hours" is not a hobby question — it is a safety question, and a vague spec sheet will not cut it. The setup takes a few minutes once, and then it is done forever. Add your circuits, pick your priorities, save a scenario or two, and the plan lives quietly on your phone until the day you need it. No syncing, no re-downloading, no subscription that expires at the worst possible moment. Whether you just installed a battery, drive an EV that can power your home, or keep a generator in the garage for hurricane season, BackupHours turns specs on a box into a number you can actually act on. • Runtime calculator for battery, solar, EV V2H and generator sources • Build a custom appliance and circuit list with real wattages • Load-shed prioritization: Critical, Important, Optional tiers • Generator mode with fuel-aware burn-rate runtime • Solar recharge estimate for multi-day off-grid scenarios • Saved outage scenarios you can plan before the storm • Inverter efficiency and depth-of-discharge built into the math • 100% offline, no account, no subscription, works in a blackout