Battery Sizing Calculator
Calculate the optimal battery bank capacity for your off-grid or backup system based on your daily loads and autonomy requirements.
Daily Loads
System Parameters
Backup duration without solar
Max recommended discharge
Battery bank voltage
Results
Enter your loads and click calculate to see results
How to Use This Calculator
1. List Your Loads
Add each appliance you want to power, with its wattage and daily hours of use. Check appliance labels or use a kill-a-watt meter for accurate readings.
2. Set Autonomy Days
Choose how many days of backup you need without solar charging. 1-2 days is typical for grid-tie backup; 3-5 days for off-grid.
3. Choose Battery Type
Lead acid batteries should only be discharged to 50%. LiFePO4 batteries can safely discharge to 80-90% for more usable capacity.
4. Select System Voltage
48V is standard for most residential systems. 12V and 24V are common for smaller off-grid or RV applications.
Need help sizing your battery bank?
Our team can review your loads and recommend the right solution.