A battery tester is a compact and easy-to-use device designed to quickly check the charge level and overall condition of different types of batteries. It supports common battery sizes such as AA, AAA, C, D, 9V, and button cells, making it ideal for household, office, and workshop use. By simply placing the battery in the tester, users can instantly see whether it is good, low, or needs replacement, helping prevent device failures and wasted time. Durable and portable in design, a battery tester provides accurate readings without the need for complex setup, ensuring reliable performance and convenience for everyday battery management.