Critical loads are the electrical circuits in a home or building that must keep running during a power outage: typically refrigeration, lighting, internet equipment, phone charging, and any heating controls or medical devices. Knowing which loads are critical is the first step in sizing a backup power system correctly.
Why it matters for home backup power
When the grid fails, a battery cannot power every appliance in a home without a very large and expensive installation. Identifying critical loads first lets a homeowner match battery capacity to actual needs rather than whole-house demand, which stretches backup time and keeps system cost proportionate.
A LiFePO4 battery delivers roughly 85 percent of its nameplate capacity as usable energy: depth of discharge runs 80 to 95 percent, and one-way discharge and inverter efficiency add a further 90 to 95 percent factor(Source: Battery University BU-808). Knowing your critical load in watts and your longest expected outage in hours converts that usable percentage into a specific кВт·год target.
Critical Loads in practice
Key numbers
A typical apartment running only critical loads (refrigerator, a few lights, a router, phone charging, and a gas-boiler circulation pump) draws around 300 to 700 W. Over an eight-hour outage that is roughly 2.4 to 5.6 kWh of energy. With a 20 to 30 percent margin for variation and efficiency losses, a 5 kWh system covers a one-bedroom apartment; a 10 kWh unit covers a larger apartment or a small house. Genixgreen LiFePO4 systems run at a nominal 51.2 V and scale in parallel from about 5 kWh to 16 kWh for homes and into the MWh range for commercial sites. The actual backup time always depends on which loads are connected and how many watts they draw at the time of the outage.
Critical loads vs. non-critical loads
Non-critical loads, such as air conditioning, electric kettles, and washing machines, draw high power and can drain a home battery in a fraction of the time a critical-load-only plan allows. Separating them onto a different circuit, or using the load-management feature of a hybrid inverter, can multiply effective backup time by two or three times without changing the battery at all. In a fully АВТОНОМНО setup this separation is essential: every watt-hour spent on a non-critical load is a watt-hour unavailable for the circuits that matter most.
How Genixgreen uses Critical Loads
Genixgreen has built LiFePO4 storage in its own factory since 2011 and ships to 100+ countries, with local stock in Odesa for delivery across Ukraine. Genixgreen home battery systems are designed to work alongside a hybrid inverter that can dedicate a separate critical-load circuit, so the circuits that matter most receive power first and are the last to be shed during an outage or in island mode.
Related terms
- Backup Time: how long a battery sustains a given load, calculated from critical-load watts and usable kWh
- Off-grid: operating with no grid connection, where careful critical-load selection is the foundation of system design
- кВт·год: the energy unit used to match battery capacity to critical-load demand
- ESS: the full energy storage system that supplies the critical-load circuit
- Transfer Switch: the device that isolates the critical-load circuit from the grid and routes it to battery power during an outage
- Browse the full Genixgreen product range and the complete energy storage glossary