Solar Battery Size Calculator
Calculate the perfect battery capacity for your solar power system
Our solar experts can design a custom system for your exact needs. Get a free consultation today!
How to Use This Calculator
- Enter your daily energy usage in kWh
- Specify how many days of backup power you need
- Select your battery type and system voltage
- Click “Calculate” to get your results
Properly sizing your solar battery bank ensures you have enough power when you need it while maximizing battery lifespan. Undersizing leads to power shortages, while oversizing increases costs unnecessarily.
Frequently Asked Questions
Depth of Discharge refers to how much of a battery’s capacity is used before recharging. For example, 50% DoD means you only use half the battery’s capacity. Lower DoD extends battery life, especially for lead-acid batteries.
Check your electricity bill for monthly kWh usage and divide by 30. Alternatively, sum the wattage of all devices you’ll power multiplied by hours used each day, then divide by 1000 to get kWh.
Higher voltage systems are more efficient for larger installations. 12V works for small systems (under 1kW), 24V for medium (1-3kW), and 48V for larger systems (3kW+). Higher voltage reduces current and allows thinner wires.
No, you should never mix different battery types (lead-acid with lithium) or even batteries of different ages/capacities in the same bank. This can cause charging imbalances and reduce performance.
Lithium batteries last 10-15 years with 4000-7000 cycles. Lead-acid lasts 3-5 years with 500-1000 cycles. Actual lifespan depends on depth of discharge, temperature, and maintenance.