Ignoring the water lost by evaporation, some water has still to be added periodically into the battery used in an invertor or car. Why? Why this is not requried in the maintenance free batteries?

Explanation

### Step-by-Step Solution:

1. **Understanding Battery Function**: Batteries, such as those used in inverters or cars, operate through electrochemical reactions. During these reactions, water (H2O) can be consumed, leading to a decrease in the water level in the electrolyte solution.

**Hint**: Think about the chemical reactions occurring in the battery and how they might affect the components involved.

2. **Electrolysis of Water**: When the battery discharges, the water can undergo electrolysis, breaking down into hydrogen (H2) and oxygen (O2) gases. This process reduces the concentration of water in the electrolyte solution, which is crucial for maintaining the battery's efficiency.

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