What is the battery model for the CX4 key?
2 Answers
The battery model is CR2025. It is a lithium manganese dioxide battery, named according to the IEC standard. Details are as follows: C - Indicates a chemical battery system with lithium metal as the negative electrode and manganese dioxide as the positive electrode; R - Indicates the battery shape is cylindrical (if square, F is used instead); 20 - Indicates the battery diameter is 20mm; 25 - Indicates the battery height is 2.5mm. The nominal voltage is 3.0V, endpoint voltage is 2.0V, and rated capacity ranges from 140-170mAh. CR2025 typically has a lifespan of 5 years. However, poor manufacturing standards or quality control can significantly shorten this lifespan. Domestic first-tier brand batteries can generally guarantee this lifespan. Under ideal conditions (sealed, room temperature, no moisture interference, etc.), the lifespan can extend to 8 years or even 10 years. The usage time of a vehicle remote key battery is closely related to usage frequency—higher frequency leads to shorter battery life. If the remote key battery is dead, the mechanical key can be used directly to unlock and start the vehicle. Car remote keys use button batteries, primarily three types: CR2016, CR2025, and CR2032. The specific model used for each vehicle can be found in the user manual for replacement. Button-type CR2016 battery: This is one of the most commonly used remote key batteries. The battery voltage is 3V, and most car key batteries operate at 9V, so three batteries need replacement each time. Examples include Honda, Toyota, Volkswagen, Mazda, etc. CR2016 specifications: battery diameter is 20mm, thickness is 1.6mm. Button-type CR2025 battery: Its usage rate is much lower than CR2016, but some car keys still use it. It is thicker than CR2016 but has a relatively higher storage capacity. CR2025 specifications: battery diameter is 20mm, thickness is 2.5mm. This type of battery is also commonly used in audio remotes. Button-type CR2032 battery: The voltage is also 3V, but the capacity is around 200mAh, making it twice as thick as CR2016. The 3V-CR2032 lithium manganese battery has a lithium-manganese dioxide structure. The positive electrode material is chemically stable manganese dioxide, the negative electrode is lithium metal, and the electrolyte is a lithium battery solution. The main components of the electrolyte are ethylene glycol dimethyl ether, propylene carbonate, and lithium perchlorate. Its shape resembles a button, hence the name button lithium battery or lithium manganese button battery. Button-type CR2450 battery: Compared to the other three, it is thicker and larger, with a diameter of 24.5mm and a height of 5.0mm. The rated current for CR2450 is 0.2mA, mainly used in low-power electronic products. Generally, these batteries can provide an output current of 0.001mA to 5mA, with continuous output up to 15mA and pulse output up to 30mA, meeting the requirements for light emission, sound, and RF output in most small electronic devices.
As a CX-4 owner, I replaced the key battery myself last month. The battery model is CR2032 lithium-manganese, which is that small round button cell commonly available in electronics stores or supermarkets for about 8 yuan each. The replacement process is quite simple: first gently pry open the gap on the back of the key with a thin tool or small screwdriver, remove the old battery after opening the cover, paying attention to the polarity markings to avoid incorrect installation. After inserting the new battery, press the cover firmly to complete. I recommend replacing it every two years, as the battery lifespan is approximately 18 to 24 months, shorter for frequent users. Keeping a spare battery in the glove box is practical - if the remote fails, you can fix it yourself to avoid inconvenience. Also, avoid exposing the key to water or high temperatures to prevent premature battery depletion.
