Sizing an off-grid or backup battery starts with your daily energy use, multiplied by how many days you want to run without sun, then divided by the usable depth of discharge (lithium batteries safely use ~80–90%).
Go solar
Power essentials.
Portable power station
Battery backup, ready to go.
Solar panel kit
Charge from the sun.
Affiliate links — as an Amazon Associate ABOS Digital earns from qualifying purchases.
Frequently asked questions
How do I size a solar battery?
Battery kWh = daily usage × days of autonomy ÷ depth of discharge. Add margin for cold and ageing.
What depth of discharge should I use?
About 80–90% for lithium (LiFePO4); 50% for lead-acid to protect its lifespan.