YKL WORLD Battery Tester, Digital LCD Universal Battery Checker for AA AAA C D 9V 1.5V Button Cell Batteries (Model: BT-168D) Do not need internal battery PORTABLE & PRACTICAL: Small and light weight, but effective, quickly test the voltage of your battery, display by digital. COMPATIBLE: Universal checker for most of household batteries. Check the power level of AA, AAA, C, D, 1.5V,9V and button type miniature cells. NO NEED BATTERIES TO OPERATE: Battery tester has no internal battery. It is powered by the battery being tested. IDEAL TOOL FOR HOME USE: Test if the battery is good, low, or needs to be replaced. A must buy household measuring tools. Quick test shows if the battery needs a replacement or not. 100% RISK-FREE SATISFACTION GUARANTEE: 100% money back with unsatisfaction shopping experience! (YKL World battery testers are changing packages. You may get new or old package. Please kindly make order from YKL World to avoid defective items.) 1.5V----AAA,HP6,MN2400,RO3,AA,HP7,MN1500,UM3C, HP11, MN1400, UM2,D,HP2, MN1300, UM1 and Cell Button batteries. 9V------ PP3,MN1604,6F22,006P Good: 1.5V~1.28V Low power: 1.27V~1.15V Need replace Below 1.15V(For Battery Size 1.5V) Good: 9V~7.8V Low power: 7.7V~6V Need replace Below 6V(For Battery Size 9V) You can simply test battery voltage to determine whether the capacity of the battery is low or high. It won&#039;t directly detect the battery capacity precisely Don&#039;t forget : The aa aaa Battery Tester is activated by the battery being checked .Kepp test times as short as poosible,to avoid unnecessary battery drain. If the digits did not show the check that battery is touching both contacts, otherwise the battery is completely dead.