After replaced the storage battery, release the red clip of the tool, if the tool is still beeps, it means you have replaced the battery successfully, if no voice, indicating fuse burned. Using this simple tool when replacing your car battery help you these problems. The power management system with core processor can display battery voltage (to prevent the use of low-power batteries, which cannot achieve the purpose of battery replacement without power failure); It can display current (can be used for leakage detection, and can also understand whether the car is Static current in the startup state) Battery clamp anti-reverse connection protection (red light turn on to remind you after reverse connection) Overcurrent protection (with built-in 5A fuse); Instructions for use If the digital tube does not display after the battery is clamped, please clamp the battery again If the car battery is seriously depleted, plugging in the battery replacement tool is equivalent to directly charging the car battery, and the current can reach several amperes or even dozens of amperes. Since the tool's fuse is 5A, it cause the battery replacement tool fuse to burn out and fail to reach The purpose of replacing the battery without disconnecting the power supply. The correct method is to the vehicle battery, restart it, and fully charge the battery before replacing the battery. Note: Installation guide not included, we strongly recommend you professional installation. Please check as much as possible to make sure the item is what you need. Tips: The product may be updated constantly ,Due To Different Batches, The Actual Product May Have Slight Differences Or Color Differences, Which Does Not Affect Use Colour:Photo Color Material:ABS Package Contents: 1 x Detection tool Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.