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Battery Life Formula:
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The battery life calculation estimates how long a battery will last based on its capacity (mAh) and the current draw (mA) of the device it powers. This helps in selecting appropriate batteries for electronic devices.
The calculator uses the battery life equation:
Where:
Explanation: The equation divides the total charge capacity of the battery by the rate at which charge is being used to determine how many hours the battery will last.
Details: Accurate battery life estimation is crucial for designing electronic devices, planning power requirements, and ensuring devices can operate for their intended duration without frequent recharging or battery replacement.
Tips: Enter battery capacity in mAh and current draw in mA. Both values must be positive numbers. The result shows estimated battery life in hours.
Q1: Is this calculation accurate for all battery types?
A: This provides a theoretical maximum. Real-world results vary due to factors like battery age, temperature, discharge rate effects, and circuit efficiency.
Q2: How does voltage factor into this calculation?
A: This simple calculation assumes constant voltage. For more precise calculations, power (mWh) should be considered when voltages differ between battery and device.
Q3: What's a typical mAh range for common batteries?
A: AA batteries: 1000-3000mAh, smartphone batteries: 2000-5000mAh, laptop batteries: 4000-10000mAh.
Q4: How does battery discharge rate affect the calculation?
A: High discharge rates often reduce effective capacity (especially for alkaline batteries), while lithium batteries maintain capacity better at higher currents.
Q5: Can this be used for battery packs in series/parallel?
A: For parallel packs, sum the mAh. For series packs, mAh stays the same but voltage increases. The calculation still works if the device draws the same current at the higher voltage.