Keywords: lead-acid battery capacity calculation, home solar battery sizing, battery Ah calculation, energy storage system design
Introduction
Incorrect battery capacity sizing is one of the most common mistakes in residential energy storage system design. Oversizing wastes budget, while undersizing leads to frequent deep discharges and shortened battery life.
1. Daily Energy Consumption Assessment
Calculate total daily load consumption in watt-hours (Wh), considering:
- Lighting
- Refrigeration
- Communication devices
- Essential appliances
2. Backup Days Requirement
Determine how many days of autonomy the system must support during grid outages or low solar production.
3. Adjust for Lead-Acid Characteristics
Unlike lithium batteries, lead-acid batteries should not be discharged fully. Typically:
- Recommended DoD: 50%
- System efficiency factor: 0.8
4. Sample Capacity Formula
Battery Capacity (Ah) =
(Daily Load × Backup Days) ÷ (System Voltage × DoD × Efficiency)
Conclusion
Accurate capacity calculation protects lead-acid batteries from overuse, significantly extending service life and reducing replacement costs.
