1. What is Battery Backup Time?

Battery backup time refers to how long a battery system can power electrical equipment during a power outage. It depends on the battery's capacity, voltage, efficiency, and the power consumption of the connected load.

2. How Does the Calculator Work?

The calculator uses the backup time formula:

Where:

• Battery Capacity — Measured in ampere-hours (Ah)
• Battery Voltage — Nominal voltage of the battery (V)
• Efficiency — Typically 85-95% (0.85-0.95) for lead-acid batteries
• Load — Power consumption of connected devices (W)

Explanation: The formula converts battery capacity to watt-hours (by multiplying Ah × V), accounts for efficiency losses, then divides by load power to get runtime.

3. Importance of Backup Time Calculation

Details: Accurate backup time estimation is crucial for designing reliable power backup systems, ensuring critical equipment remains operational during outages.

4. Using the Calculator

Tips: Enter battery capacity in Ah, voltage in V, efficiency factor (0.85 typical for lead-acid), and load power in W. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What's typical efficiency for different battery types?
A: Lead-acid: 85-90%, Lithium-ion: 95-98%, NiMH: 80-85%.

Q2: How does battery age affect backup time?
A: As batteries age, their capacity decreases - older batteries may provide significantly less runtime than when new.

Q3: Should I derate the calculated backup time?
A: Yes, it's wise to assume 80% of calculated time for safety margin, especially with older batteries.

Q4: How does temperature affect backup time?
A: Cold temperatures reduce battery capacity, while high temperatures can increase capacity but shorten battery life.

Q5: Can I connect multiple batteries for longer backup?
A: Yes, connecting batteries in parallel increases capacity (Ah) while maintaining voltage, extending runtime proportionally.