Direct dial display: The measurement plate and pointer show the result clearly, making it easy to read the battery status at a glance. Simple operation: Easy to use from the first try; just insert the battery and pay attention to correct polarity. No power required: Does not need an external power source to test; quickly determine if a 1.5V AA battery, AA battery, or 9V square battery is sufficient. Homefriendly tester: A compact battery capacity tester well suited for household use; tells you whether the battery is good. Compatibility and performance: Designed to work with common battery types and provide a straightforward indication of battery condition. Practical use scenarios: Check batteries for remote controls, wireless keyboards, and game controllers. Test batteries in wall clocks, toys, and flashlights. Quick preuse check for emergency lighting and portable devices before trips.