When working with lead-acid batteries, what precaution should always be taken?

When working with lead-acid batteries, maintaining proper ventilation while charging is essential due to the potential release of hydrogen gas. This gas can accumulate and create an explosive atmosphere, especially in enclosed spaces. Proper ventilation allows the hydrogen gas to dissipate safely, minimizing the risk of ignition and explosion. Charging in an area with adequate airflow helps ensure that any gases produced during the charging process do not pose a hazard.

While using gloves, keeping batteries at room temperature, and disconnecting the power supply are all relevant safety measures when handling batteries, they do not address the specific risks associated with gas emissions during the charging process. Proper ventilation directly mitigates these risks and is therefore a critical precaution to take.