电池储能容量选型计算器
使用电池储能容量选型计算器精确确定最佳电池系统规格。根据日均用电量、峰值负荷和放电深度，计算所需的kWh容量和电池数量，优化储能投资。
Required Battery Capacity
83.3 kWh
Required Battery Capacity vs Daily Energy Usage
公式
Sizing Battery Storage for Solar
Battery storage bridges the gap between solar generation and energy use, especially overnight or during cloudy days.
Formula
Required Capacity = (Daily Usage x Autonomy Days) / DoD / Round-Trip Efficiency
Depth of Discharge (DoD) is the fraction of the battery you can actually use without damaging it. Lithium-ion batteries typically allow 80-90% DoD, while lead-acid batteries are limited to 50%.
计算示例
A home uses 30 kWh/day and wants 2 days of autonomy with 80% DoD and 90% efficiency.
- 01Energy needed = 30 x 2 = 60 kWh
- 02Account for efficiency = 60 / 0.90 = 66.7 kWh usable
- 03Account for DoD = 66.7 / 0.80 = 83.3 kWh total capacity
常见问题
What is depth of discharge?
DoD is the percentage of battery capacity you can use. A 10 kWh battery with 80% DoD provides 8 kWh of usable energy. Deeper discharge shortens battery life.
How many days of autonomy do I need?
For grid-tied systems, 1 day is common for backup. Off-grid systems typically need 2-3 days to cover cloudy periods.
Lithium vs lead-acid batteries?
Lithium-ion batteries offer 80-90% DoD, 90-95% efficiency, and 10+ year life. Lead-acid has 50% DoD, 80% efficiency, and 3-5 year life but costs less upfront.