Home
>
Solar Storage Battery Calculator
Sizing Tool

Solar Storage Battery Calculator

Add your everyday appliances, choose how long you need backup power, and get a clear battery size estimate in seconds.

1. Add your appliances

Choose a common appliance below, or enter your own. Adjust the power, hours and quantity to match your home.

Quick add
2. Choose your backup settings

The defaults work for a typical indoor LiFePO4 setup. Change them only if your installation needs differ.

Backup timeChoose 0.5 for overnight backup, 1 for a full day, or more for longer outages.
days
Usable battery capacity90% means you plan to use up to 90% of the battery’s rated capacity.
Battery room temperatureChoose the coldest typical temperature where the battery will be installed. Cold weather can reduce usable energy.
Your battery estimate

Updates as you add appliances and change settings.

0
Daily consumption (kWh)
0
Recommended battery (kWh)

Add an appliance to see your estimated battery size.

How do I calculate what size battery I need?
Sum each appliance's watts × running hours × quantity to get daily kWh. Multiply by your autonomy days, then divide by depth of discharge (e.g. 0.9) and a low-temperature derating factor if installed below 0°C. The result is the recommended rated capacity in kWh.
Why LiFePO4 for home energy storage?
LiFePO4 chemistry delivers 6000+ cycles at 90% DoD, stable thermal behaviour without cobalt, and 10-year class service life — a lower cost per kWh stored than lead-acid or NMC over the system lifetime.
Can I expand the battery later?
Gobel home batteries support parallel expansion — rack modules scale in single-unit steps while floor-standing cabinets reach system sizes above 160 kWh. Plan busbar and inverter capacity at purchase; our engineers help size the expansion path.