How can you check the condition of a boat's battery?

To assess the condition of a boat's battery effectively, using a multimeter to measure voltage is essential. This tool allows you to determine the voltage level of the battery, which can indicate whether it is charged properly. A healthy, fully charged battery typically shows around 12.6 volts or more. Lower voltage readings can suggest that the battery is discharged or potentially failing.

In addition to voltage measurement, checking for physical damage is important, as any signs of corrosion, swelling, or leaking can be indicators of battery problems. Physical damage may compromise the battery's functionality and safety, so inspecting it visually is essential for a thorough evaluation.

The other options, while they may offer insights into the boat's overall functionality, do not directly address the battery's condition. Monitoring fuel efficiency or observing a battery light indicator relates more to the operational aspects of the boat rather than specifically diagnosing battery health. Measuring engine temperature is unrelated to battery assessment. Thus, the combination of voltage measurement and physical inspection through a multimeter provides the most accurate evaluation of the battery's status.