*Question G6A01:
What is the minimum allowable discharge voltage for maximum life of a standard 12-volt lead-acid battery?*  

*Correct Answer is  C: 10.5 volts*  

### AI Response: (may contain errors)  

For a standard 12-volt lead-acid battery, the minimum allowable discharge voltage for maximum life is 10.5 volts. Here's why:

1. **Correct Answer: 10.5 volts (Choice C)**
   - Lead-acid batteries are designed to operate within a specific voltage range to ensure longevity and efficiency. Discharging a lead-acid battery below 10.5 volts can lead to sulfation, which is a condition where lead sulfate crystals form on the battery plates. This can permanently reduce the battery's capacity and lifespan.
   - Maintaining a discharge voltage of no less than 10.5 volts helps prevent deep discharge, which is detrimental to the battery's health.

2. **Why the Other Choices are Incorrect:**
   - **6 volts (Choice A):** Discharging a 12-volt lead-acid battery to 6 volts is considered a deep discharge. This level of discharge can cause significant damage to the battery, leading to a drastic reduction in its lifespan and capacity.
   - **8.5 volts (Choice B):** While not as severe as 6 volts, discharging to 8.5 volts still constitutes a deep discharge. It can cause sulfation and other forms of damage, reducing the battery's life.
   - **12 volts (Choice D):** This is the nominal voltage of a fully charged lead-acid battery. Discharging to 12 volts means the battery is not being used at all, which is impractical for most applications. It does not represent a minimum discharge level.

**Rule of Thumb:**
- For maximum battery life, avoid discharging a lead-acid battery below 10.5 volts. This helps prevent damage and maintains the battery's capacity over time.