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Battery Run Time Equation:
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Battery run time calculation estimates how long a lithium-ion battery can power a device before needing recharge. It's essential for planning power usage in various applications from electronics to electric vehicles.
The calculator uses the fundamental battery equation:
Where:
Explanation: This simple division gives the theoretical run time in hours, assuming constant current draw and 100% battery efficiency.
Details: Accurate run time estimation helps in selecting appropriate battery sizes for applications, planning usage patterns, and ensuring devices operate as expected without unexpected power loss.
Tips: Enter battery capacity in Ah and load current in A. Both values must be positive numbers. The result shows estimated run time in hours.
Q1: Is this calculation accurate for all lithium-ion batteries?
A: This provides theoretical maximum. Actual run time may vary due to temperature, battery age, discharge rate, and efficiency losses.
Q2: What factors affect actual battery run time?
A: Temperature, discharge rate, battery age, depth of discharge, and overall system efficiency can all impact actual performance.
Q3: How does battery voltage affect this calculation?
A: The calculation uses current (Amperes) and capacity (Ampere-hours), making it voltage-independent for time estimation.
Q4: Can I use this for battery packs in series/parallel?
A: For parallel configurations, add capacities. For series, voltage increases but capacity remains the same per this calculation.
Q5: Why might actual run time be less than calculated?
A: Battery efficiency (typically 80-90%), voltage drop under load, and protective circuit operation can reduce actual run time.