Determine the ideal battery bank size for your solar energy system with our user-friendly calculator. Input your daily power consumption, desired backup duration, battery type, and system voltage to receive accurate capacity recommendations tailored to your needs. Whether you're considering lead-acid, lithium, or LiFePO₄ batteries, our tool simplifies the process, ensuring optimal performance and efficiency for your renewable energy setup.
Solar Battery Bank Calculator
Calculation Results
Solar Battery Calculator Instruction
1. Input Parameters Specification
| Input Field | Description | Unit | Required |
|---|---|---|---|
| Daily Energy Consumption | Average daily electricity usage | kWh | Yes |
| Backup Hours Required | Duration of autonomous operation | Hours | Yes |
| Peak Power Demand | Maximum instantaneous power load | kW | Yes |
| Battery Type | Determines Depth of Discharge (DOD) | - | Yes |
| System Voltage | DC system operating voltage | Volts (V) | Yes |
| Inverter Efficiency | Power conversion efficiency | % | Yes |
| Solar Panel Size | Solar array capacity (optional) | kW | No |
2. Calculation Process
Core Formulas
1. Hourly Energy Consumption:
Hourly Usage (kWh) = Daily Consumption / 24
2. Total Energy Requirement:
Total Energy = Hourly Usage × Backup Hours
3. Battery Capacity:
Battery (Ah) = (Total Energy × 1000) / (DOD × Efficiency × Voltage)
4. Inverter Sizing:
Inverter (kW) = Peak Power × 1.2
5. Solar Charging Time (optional):
Charge Hours = Total Energy / (Solar Size × Efficiency)
3. Practical Example
Sample Inputs
- Daily Consumption: 25 kWh
- Backup Hours: 36 hours
- Peak Power: 7.5 kW
- Battery: Li-Ion (DOD=0.8)
- Voltage: 48V
- Inverter Efficiency: 92%
- Solar Panel: 5 kW
Calculation Steps
- Hourly Usage: 25/24 = 1.042 kWh
- Total Energy: 1.042 × 36 = 37.5 kWh
- Battery Capacity: (37.5×1000)/(0.8×0.92×48) = 1,118 Ah
- Inverter Size: 7.5 × 1.2 = 9 kW
- Charging Time: 37.5/(5×0.92) = 8.15 hours
4. Engineering Notes
Critical Considerations
- Add 15-20% capacity buffer for battery aging
- Temperature derating factors:
- +35°C: ×0.9 capacity
- -10°C: ×0.75 capacity
- Inverter surge capacity should exceed motor starting loads
- Solar charging assumes 4-5 peak sun hours daily
Once you know your ideal battery bank size, the next step is choosing the right unit. BSLBATT manufactures LiFePO4 solar batteries from 5 kWh to 30 kWh with 90% depth of discharge and 6,000+ cycle life. Explore the BSLBATT 5kWh Battery, BSLBATT 10kWh Battery, BSLBATT 15kWh Battery as a popular starting point for whole-home solar storage.