Batteries
Intermediate
Sizing Your Battery Bank
How to size a battery bank for off-grid or backup use, including depth-of-discharge considerations and lithium vs. lead-acid choices.
20 min read
Basic electrical knowledge
Daily Energy Needs
Start with your daily kWh consumption. Multiply by 1.3 to account for inverter and wiring losses. This is how much energy your battery bank must hold (before depth-of-discharge limits).
Depth of Discharge
Lead-acid batteries should not be discharged past 50%. Lithium batteries can typically go to 80-100%. Divide your needed capacity by the allowable DoD to get the rated capacity.
Voltage Matters
Higher system voltages (24V/48V) use thinner wire and are more efficient for larger systems. Choose an inverter and MPPT charge controller that match your chosen bank voltage.