Battery Tester (2 Pack), HAOBAOBEI Universal Battery Monitor Checker for AA AAA C D 9V 1.5V Button Cell Batteries, Small Electrical Equipment Battery Life Level Testers Power Meter (Model: BT-168): Amazon.com: Electronics
Amazon.com: Amazon Basics LR44 Alkaline Button Coin Cell Battery, 1.5 Volt, Long Lasting Power, Mercury Free - Pack of 6 : Health & Household