BT189 UltraSmall Battery Tester Ultra compact and portable: designed in an ultracompact size for easy carrying during travel, allowing you to test batteries anywhere without hassle. A practical tool for home and outdoor use. Versatile compatibility: tests nonrechargeable batteries such as 9V, AA, AAA, and button cells. Not suitable for measuring rechargeable batteries. Clear LCD display: digital readout provides quick, accurate voltage and capacity readings, helping you assess battery health and avoid unexpected power loss. Power bank detection: easily determine whether a connected device is a power bank, helping you manage power sources in critical moments. Simple, reliable performance: straightforward operation with no complicated setup, giving you fast results you can trust. Use scenarios At home: verify batteries in remotes, wall clocks, and toys to know when replacement is needed. On the go or outdoors: carry the BT189 to check spare batteries for flashlights, cameras, or radios and decide if replacements are required. In travel or work environments: quickly identify if a device is a power bank and ensure you have reliable power sources for essential equipment.