Which device is best for checking the overall condition of a battery?

A battery load tester is specifically designed to evaluate the overall condition of a battery by applying a load and measuring its performance under that load. When a load is applied, the tester checks how the battery reacts, revealing its ability to deliver the necessary power when required. This is crucial for understanding the battery's health because a battery may show a good voltage reading when not under load, but if it cannot maintain that voltage when a load is applied, it indicates that the battery may be failing.

In contrast, a multimeter is a versatile tool that can measure voltage and current but does not put a load on the battery, which is essential for a comprehensive assessment. A clamp-on ammeter measures current flow in a wire without interruption but doesn't provide insight into battery condition. A voltage tester simply checks for the presence of voltage but does not provide detailed insights into the battery's actual capacity or health under work conditions.

Therefore, the battery load tester is the most appropriate device for assessing the overall condition of a battery, as it simulates real-world usage conditions.