Convenient to measure: no need to waste time and energy on complicated tools. Simply attach the black wire to the negative pole of the battery and use the copper tip pen to touch the positive pole. You will get a quick and reliable reading of your battery status. Portable and comfortable: Our battery load tester has an ergonomic handle and compact size, making it easy and comfortable to carry and to use. It has a simple design that allows you to test your battery quickly and accurately. 3 ID lights: The indicator lights on the panel are your reliable guide to the battery charge level. They display three light colors (red, yellow and green) which reflect the status of your battery and charging system. Therefore, you can easily spot and resolve any issues. High Accuracy: This battery capacity tester provides accurate and reliable measurements of battery voltage and charging system health . It is equipped with a microcomputer control chip that promotes its precision. Maintain normal battery operation: undervoltage or overvoltage may cause damage or breakdown to your car. This voltage tester allows you to test the battery and motor regularly to avoid these problems. The normal working voltage of the charging system is also displayed by this voltage tester.