1. What is Battery Run Time?

Battery run time is the duration a battery can power a device before needing recharge. For 12V batteries, it depends on the battery's capacity (in amp-hours) and the power consumption of the connected load (in watts).

2. How Does the Calculator Work?

The calculator uses the following equation:

Where:

• Battery Capacity — The energy storage capacity of the battery in amp-hours (Ah)
• 12V — The nominal voltage of the battery
• Load Power — The power consumption of the connected device in watts (W)

Explanation: The equation calculates how long a 12V battery can sustain a given power load based on its capacity.

3. Importance of Run Time Calculation

Details: Accurate run time estimation is crucial for designing power systems, emergency backup planning, and ensuring continuous operation of critical devices.

4. Using the Calculator

Tips: Enter battery capacity in Ah and load power in W. All values must be positive numbers for accurate calculation.

5. Frequently Asked Questions (FAQ)

Q1: Is this calculation accurate for all 12V batteries?
A: This provides an estimate. Actual run time may vary based on battery age, temperature, discharge rate, and other factors.

Q2: What's the difference between Ah and Wh?
A: Ah (amp-hours) measures charge capacity, while Wh (watt-hours) measures energy capacity. For 12V batteries, Wh = Ah × 12.

Q3: How does battery type affect run time?
A: Different battery chemistries (lead-acid, Li-ion, etc.) have different discharge characteristics and depth-of-discharge limits.

Q4: Why does run time decrease with higher loads?
A: Higher loads cause higher current draw, which can reduce battery capacity due to the Peukert effect (especially in lead-acid batteries).

Q5: Should I derate the calculated run time?
A: For critical applications, it's wise to use 70-80% of calculated run time to account for inefficiencies and battery aging.