Gardner Bender GBT-500A Analog Battery Tester, Batteries 1.5V to 22.5V, Easy-to-Read Indicator, Includes Test LeadsCategory: Car Battery PartsThis tester couldn't be better! In just seconds you'll know if that battery you found in the junk drawer, basement or garage still has a charge or needs to be tossed. No outside power source needed; simply touch either the positive or negative side of battery to the corresponding contact point on the tester face and then touch the correct test lead to opposite side of battery. The scale indicates a weak battery when the needle drops with an easy-to-read selector switch and color coded "Good/Replace" indicator. Extra-features include positive and negative contact posts on the front of the tester making 9V battery checks quick and easy and a button cell retainer with press-down test button that holds the cell in place while testing. Because this unit measures the voltage by applying an appropriate load, rather than just testing the "open cell" voltage you get a more accurate result. Tests: 1.5V Button cells, 1.5V AAA, N, AA, C, D cells, 1.25V Nickel-Cadmium rechargeable cells, 3V Lithium cells, 6V Lantern and photo light meter cells, 9V Rectangular, 12V, 15V Photo cells, and 22.5V Photo and lantern cells with Voltage Rating of 1.5V to 22.5V. Unit includes the test leads and offers a 1 year warranty. Bottom line, if you use batteries (and who doesn't?), you should own one of these testers.