How long the battery lasts

Choose the battery, how many, the inverter and the power of what must run without the grid — the calculator shows the hours of autonomy.

BatteryBatteries, pcsInverterLoad power, W

Roughly: fridge ≈ 150 W, router ≈ 20 W, LED lights ≈ 50 W, boiler pump ≈ 100 W, laptop ≈ 60 W, TV ≈ 100 W. Add what runs at the same time.

Battery capacity10.24 kWh

Usable energy8.29 kWh

Lasts≈ 16.6 h

Invertercarries the load (5 kW)

Open in the designer

How it is calculated

Usable energy = count × capacity × depth of discharge (DoD, from the datasheet) × inverter efficiency 0.9 (assumed). Hours = usable energy / load power. No PV recharge (night or a cloudy day). The inverter must carry the load — otherwise it shuts down.

The calculation is preliminary. A qualified engineer must check it before installation. Codes: DBN V.1.2-2:2006 (Ukraine) and the Eurocode; for other countries — snow and wind values from the national annex, entered by hand.