Maplin Mercury Universal Analogue Battery Tester for AA, AAA, C, D, 9V PP3 & Coin Button Cells Maplin Universal Analogue Battery Tester for AA, AAA, C, D, 9V PP3 & Coin Button Cells Handy, compact battery tester with an easy-to-read analogue display. Suitable for testing most household batteries and button cells. Measures the batteries under load to accurately indicate charge status Suitable for testing AA, AAA, C, D and 9V PP3 batteries and button cells Easy to read analog display needle indicates "good" (green), "low" (yellow), and "replace/recharge" (red)