1. What is Battery Backup Time?

The battery backup time is the duration a 150Ah battery can power your solar system load before needing recharge. It depends on battery voltage, system efficiency, and power consumption.

2. How Does the Calculator Work?

The calculator uses the backup time formula:

Where:

• 150 Ah — Battery capacity
• Battery Voltage — Typically 12V, 24V, or 48V for solar systems
• Efficiency — System efficiency factor (typically 0.85-0.95)
• Load — Total power consumption in watts

Explanation: The formula converts battery capacity (Ah) to energy (Wh) considering voltage, then divides by load after accounting for system losses.

3. Importance of Backup Time Calculation

Details: Knowing backup time helps design solar systems, ensure sufficient power during outages, and properly size battery banks for your needs.

4. Using the Calculator

Tips: Enter battery voltage (typically 12V, 24V, or 48V), efficiency (0.85 for lead-acid, 0.95 for lithium), and load in watts. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What's typical efficiency for lead-acid vs lithium batteries?
A: Lead-acid typically 85-90%, lithium 90-95% due to lower internal resistance.

Q2: Does depth of discharge affect backup time?
A: Yes, this calculation assumes 100% discharge. For longer battery life, reduce calculated time by your preferred DoD (e.g., multiply by 0.5 for 50% DoD).

Q3: How does battery age affect backup time?
A: As batteries age, their actual capacity decreases, reducing backup time. Consider multiplying by 0.8 for older batteries.

Q4: Can I use this for multiple batteries?
A: For parallel batteries, multiply backup time by number of batteries. For series, use the increased voltage but same Ah.

Q5: What's the impact of temperature?
A: Cold reduces battery capacity. Below freezing, capacity can drop 20-50% depending on battery type.