What is the battery model for the Audi A3 car key?
2 Answers
The battery model is CR2032. It is a lithium manganese dioxide battery, named according to the IEC standard. The breakdown is 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 it were square, F would be used instead. 20 - Indicates the battery diameter is 20mm. 32 - Represents the battery height of 3.2mm. The nominal voltage is 3.0V, the endpoint voltage is 2.0V, and the rated capacity is approximately 200mAh. CR2032 batteries typically last around 5 years. However, if the manufacturer's production standards are low or quality control is poor, the lifespan can be significantly shortened. Domestic top-tier brands generally guarantee this lifespan. If used in a sealed, room-temperature, and moisture-free environment, the lifespan can extend further to 8 or even 10 years. The usage time of a car remote key battery is closely related to the frequency of use—the more frequently it is used, the shorter the lifespan. If the remote key battery dies, the mechanical key can still be used to unlock and start the vehicle. Car remote keys use button cell 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 car remote batteries. The battery voltage is 3V, while most car key batteries operate at 9V, so all three batteries must be replaced at once. Examples include Honda, Toyota, Volkswagen, and Mazda. CR2016 specifications: 20mm diameter, 1.6mm thickness. Button-type CR2025 battery: Its usage rate is much lower than CR2016, but some car keys still use it. It is thicker than the CR2016 and has a relatively higher storage capacity. CR2025 specifications: 20mm diameter, 2.5mm thickness. This type of battery is also commonly used in audio remotes. Button-type CR2032 battery: Its thickness is double that of the CR2016. The 3V-CR2032 lithium manganese battery follows a lithium-manganese dioxide structure. The positive electrode material is chemically stable manganese dioxide, the negative electrode is metallic lithium, and the electrolyte is a lithium battery solution. The main components of the electrolyte are dimethoxyethane, propylene carbonate, and lithium perchlorate. Its shape resembles a button, hence it is also called a button lithium battery or lithium-manganese button cell.
As a long-time owner of an old Audi A3, the key fob battery tends to run out after prolonged use, and from my experience, the CR2032 model is the most common. I remember when the car was new, the key battery lasted almost two years before needing replacement. I bought a Panasonic CR2032 at Carrefour supermarket for just 5 yuan. Replacing it yourself is very simple: use a small key ring to pry open the back cover—don’t use excessive force—remove the old battery, and install the new CR2032 with the positive side facing up. After installation, test whether the unlock button lights up. I recommend checking the battery every two years. Although you can still use the mechanical key to open the door when the battery dies, it can be quite inconvenient during hot summer days or rainy weather. I usually keep a few spare CR2032 batteries in the glove box. I’ve checked online, and this type of battery typically lasts 1.5 to 2 years, though good usage habits can extend its lifespan a bit.
