Subelement I: Power Sources— Topic 60: Batteries-1
Question 3-60I3
Element 3 (GROL)What capacity in amperes does a storage battery need to be in order to operate a 50 watt transmitter for 6 hours? Assume a continuous transmitter load of 70% of the key-locked demand of 40 A, and an emergency light load of 1.5 A.
Explanation
To determine the required battery capacity, first calculate the total current draw. The transmitter's continuous load is 70% of its key-locked demand: 0.70 * 40 A = 28 A.
Next, add the emergency light load to find the total current: 28 A (transmitter) + 1.5 A (lights) = 29.5 A.
Finally, multiply the total current by the operating time to find the required ampere-hour (Ah) capacity: 29.5 A * 6 hours = 177 Ah. This calculation ensures the battery can supply the combined power needs for the specified duration, a crucial consideration for emergency or portable amateur radio operations.
Therefore, a 177 ampere-hour battery is needed.
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