1. What is Battery Runtime?

Battery runtime is the duration a battery can power a device before needing recharge. It depends on the battery's capacity, the current draw of the device, and the battery's efficiency.

2. How Does the Calculator Work?

The calculator uses the battery runtime equation:

Where:

• Battery Capacity — Total charge stored in the battery (Amp-hours)
• Efficiency — Ratio of usable energy (typically 0.7-0.9)
• Discharge Current — Current drawn by the device (Amps)

Explanation: The equation calculates how long a battery can sustain a given current draw, accounting for energy losses.

3. Importance of Runtime Calculation

Details: Accurate runtime estimation helps in system design, backup power planning, and ensuring uninterrupted operation of critical devices.

4. Using the Calculator

Tips: Enter battery capacity in Ah, efficiency as decimal (0-1), and discharge current in A. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What's typical battery efficiency?
A: Lead-acid batteries: 80-85%, Lithium-ion: 90-95%. Actual efficiency depends on temperature and discharge rate.

Q2: How does temperature affect runtime?
A: Cold temperatures reduce battery capacity and efficiency, decreasing runtime.

Q3: Should I use nominal or actual capacity?
A: Use manufacturer's rated capacity for new batteries. For aged batteries, use 70-80% of nominal capacity.

Q4: What if my current varies?
A: For variable loads, calculate runtime for each current level and sum the durations.

Q5: Does this work for battery banks?
A: Yes, sum capacities for parallel batteries. For series, use single battery capacity but higher voltage.