JLER Universal Digital Battery Tester - For AA/AAA/C/D/9V and Mini Button Cell Small Batteries Check the power level to test all household batteries Quick test shows if a device needs a replacement battery Easy-to-read indicate the power level Test standard and rechargeable batteries: 9V, AA, AAA, C, D, 1.5V Button Type Compact design Rechargeable Batteries are typically 1.2V when fully charged versus 1.5V for normal alkaline batteri Note: Battery tester has no internal battery. It is powered by the battery being tested.