Updated: Dec 9, 2025 | Source: 2023-2027 Question Pool | Topic: G6A
G6A01G6A

What is the minimum allowable discharge voltage for maximum life of a standard 12-volt lead-acid battery?

Deep Dive: G6A01

The correct answer is C: 10.5 volts. The minimum allowable discharge voltage for maximum life of a standard 12-volt lead-acid battery is 10.5 volts. Discharging below 10.5V damages the battery and reduces its life. For amateur radio operators, this is critical for battery maintenance. Understanding this helps preserve battery life.

Why Other Answers Are Wrong

Option A (6 volts): Incorrect. 6 volts is way too low - that would severely damage the battery. 6V is half the nominal voltage, which would destroy the battery. Option B (8.5 volts): Incorrect. 8.5 volts is too low - that would still damage the battery. 10.5V is the minimum for maximum life. Option D (12 volts): Incorrect. 12 volts is the nominal voltage, not the minimum discharge voltage. Batteries can discharge below 12V without damage.

Exam Tip

12V lead-acid minimum discharge = 10.5 volts. Think '1'2V battery = '1'0.5V minimum. Discharging below 10.5V damages battery and reduces life. Not 6V, not 8.5V, not 12V - just 10.5V for maximum life.

Memory Aid

12V lead-acid minimum discharge = 10.5 volts. Think '1'2V battery = '1'0.5V minimum. Discharging below 10.5V damages battery and reduces life. Critical for battery maintenance.

Real-World Example

You use a 12-volt lead-acid battery for portable operation. You monitor the voltage and stop using it when it reaches 10.5 volts. Discharging below 10.5V causes sulfation and reduces battery life. Keeping discharge above 10.5V maximizes battery life.

Source & Coverage

Question Pool: 2023-2027 Question Pool

Subelement: G6A

Reference: 2023-2027 Question Pool · G6 - Circuit Components

Key Concepts

Lead-acid battery Discharge voltage 10.5 volts Battery life

Verified Content

Question from the official FCC General Class pool. Explanation reviewed by licensed amateur radio operators and mapped to the G6A topic.