ARRL Technician Practice Exam

What is one way to recharge a 12-volt lead-acid station battery if the commercial power is out?

1. Connect the battery in parallel with a vehicle's battery and run the engine

2. Use a solar panel

3. Charge it using a standard household outlet

4. Leave it unused until power returns

The correct answer is: Connect the battery in parallel with a vehicle's battery and run the engine

Recharging a 12-volt lead-acid station battery when commercial power is unavailable can effectively be done by connecting it in parallel with a vehicle's battery and running the engine. This method is practical because the vehicle's alternator generates electricity when the engine is running, which can be used to charge both the vehicle's battery and the connected station battery simultaneously. The vehicle's electrical system is designed to output approximately 13.8 to 14.4 volts while running, which is suitable for charging a 12-volt lead-acid battery. It’s important to connect the batteries properly to avoid reverse polarity, which could damage the batteries or cause safety issues. This method provides a reliable source of power transfer from the vehicle to the station battery when grid electricity is not available. Using a solar panel is also a possible method for recharging, but it may not be as effective or efficient depending on the solar panel's size, sunlight availability, and weather conditions. This option requires more time and specific equipment that may not be available on short notice during a power outage. Charging using a standard household outlet is not feasible when there is no commercial power. Leaving the battery unused until power returns does not provide any means of recharging and merely prolongs