Automotive Electronics Practice Test

Technician A says that distilled or clean drinking water should be added to a battery when the electrolyte level is low. Technician B says that fresh electrolyte (solution of acid and water) should be added. Which technician is correct?

1. Technician A only

2. Technician B only

3. Both Technicians A and B

4. Neither Technician A nor B

The correct answer is: Technician A only

Adding distilled or clean drinking water to a battery with a low electrolyte level is appropriate because it helps maintain the proper electrolyte concentration and prevents the battery from being overfilled with a more concentrated solution. In lead-acid batteries, as the battery discharges and charges, water can evaporate, causing the electrolyte level to drop. Adding water restores this level, ensuring the battery functions correctly and the plates remain submerged to prevent damage. In contrast, adding fresh electrolyte, which is a solution of acid and water, could disturb the balance of the existing electrolyte within the battery. When adding fresh electrolyte, especially if done incorrectly or without knowing the current concentration, it can lead to overconcentration or increased acidity, both of which may result in damage or reduce the lifespan of the battery. Therefore, Technician A is correct in suggesting that distilled or clean drinking water is the appropriate solution when the electrolyte level is low in a battery.