Choosing the correct battery size for your système d'énergie solaire is essential to ensure reliable power supply, maximize efficiency, and avoid unnecessary costs. Here’s a simple guide to help you size your solar battery storage correctly.
Check your electricity bills or use an energy meter to find out how many kilowatt-hours (kWh) you consume per day.
Example: If your home uses 20 kWh/day, your battery needs to store at least this amount to cover daily needs.
How many days do you want the system to run without sunlight?
1–2 days for sunny climates
3–5 days for remote or cloudy areas
Formula:
Battery Capacity (kWh) = Daily Usage × Autonomy Days
Batteries can’t be drained completely.
Lithium-ion: 80–90% DoD
Lead-acid: 50% DoD
Adjust your capacity based on the battery type.
Losses occur in inverters and wiring. Multiply your result by 1.1–1.2 for accuracy.
Daily Usage: 20 kWh
Autonomy Days: 3
Battery Type: Lithium-ion (90% DoD)
Efficiency: 90%
Required Battery = 20 × 3 ÷ 0.9 ÷ 0.9 ≈ 74 kWh
Bluesun provides lithium-ion and LiFePO4 battery systems from 5kWh to 1MWh, perfect for residential, commercial, and off-grid projects. Our experts can size your battery based on your exact needs.
👉 Contact us for a free battery sizing consultation.
FR 
EN 
ES 
DE 
RU 
ZH 
AR 
