Review on Dlyfull LCD Battery Tester - Universal Checker For AA AAA C D 9V CR2032 CR123A & More, 2X AAA Batteries Included by Danny Porter

Using the 2 battery testers I already have, I couldn't reliably tell whether some button batteries were worth keeping or needed to be replaced. I decided to buy a different one and ordered this one. It is AMAZING. It seemed odd to put a battery in a battery tester in order for it to work, but that point aside it does a fantastic job. No matter what the household battery may be, this will accurately test it and give you a great read out to know exactly how strong it is. These might wind up in stockings this year for the holidays!