The battery model for Mazda CX4 key is CR1620. CR1620 is a lithium manganese dioxide battery, named according to the IEC standard. Among them: C- indicates a chemical battery system with lithium metal as the negative electrode and manganese dioxide as the positive electrode; R- indicates that the shape of the battery is cylindrical, if it is square, F is used instead; 16 indicates that the diameter of the battery is 16mm; 20 represents the height of the battery is 2.0mm. The nominal voltage is 3.0V, the endpoint voltage is 2.0V, and the rated capacity ranges from 140-170mAh. The shelf life of CR1620 is usually 5 years. If the manufacturer's production level is not high or quality control is poor, its lifespan will be greatly shortened. Domestic first-tier brand batteries can basically guarantee this lifespan. If the usage environment is ideal (sealed, room temperature, no moisture, etc.), its lifespan can be further extended to 8 years or even 10 years. Generally, replacing the car key battery only requires the following 3 steps: Step 1: Remove the mechanical key. Press the lock buckle on the side of the smart key to remove the mechanical key. Step 2: Open the battery cover. After removing the mechanical key, you can see a deep groove and a shallow groove at the top of the smart key. The deep groove is the keyhole, and the shallow groove is used to open the battery cover. Insert the mechanical key into the shallow groove and pry it outward with force to open the battery cover. After opening, you can see the button battery. Gently pry it, and the battery will come out. Step 3: Replace the new battery. Install the new battery, then reattach the battery cover and mechanical key in sequence, and the key battery replacement is completed.
