What Type of Battery Does a Car Key Use?
3 Answers
Car key batteries are typically CR2032, but other models include CR2025, CR2016, and CR1632. Here, "CR" stands for lithium battery, "20" indicates the battery diameter (20mm), and "32" refers to the battery thickness (3.2mm). Below is an introduction to car key battery models: 1. Button-type CR2016 Battery: This model is widely used in modern car key remotes and is one of the most common types. It has a voltage of 3V. Since car keys usually require 9V, all three batteries are typically replaced at once. Specifications: diameter of 20mm and thickness of 1.6mm. 2. Button-type CR2025 Battery: This model is less common than the CR2016. It is thicker but has a higher storage capacity. Specifications: diameter of 20mm and thickness of 2.5mm. This type is also often found in audio remote controls. 3. Alkaline 12V Battery: These were commonly used in early car key remotes and electric rolling shutters. They are compact, have high output voltage, and offer a longer remote control range.
I’ve replaced the battery in my car key before and found that different car models actually use different types of button batteries. The most common one is the CR2032, which is what my Toyota uses—a thin, round cell. However, my friend’s Honda uses a CR2025, and a colleague’s German car uses a CR2016. When you open the back cover of the key, you’ll see the battery model printed on the surface. It’s best to bring the old battery when buying a new one to match the model, because the CR2032 and CR2025 have the same diameter but differ in thickness by 0.7mm—using the wrong one can cause poor contact. You can find these batteries at the battery counter in supermarkets for just five yuan. Replacing it yourself is simple: just use a small screwdriver to pry open the key shell, make sure not to reverse the positive and negative terminals, and you’ll save the 80 yuan you’d otherwise spend at the dealership.
After years of working on cars, I've handled hundreds of car keys. Ninety percent of remote keys on the market use three types of button batteries: CR2032, CR2025, and CR2016. The first two digits of these model numbers represent the diameter (in millimeters), while the last two indicate the thickness (in 0.1 mm units). For example, CR2032 means a diameter of 20 mm and a thickness of 3.2 mm. When choosing a battery, always refer to the original manufacturer's model number, as different thicknesses can affect the key's circuit contact points. Use a plastic pry tool to open the casing when replacing the battery, as metal tools might scratch the contacts. Before installing the new battery, remember to clean the electrode contact strips with a cotton swab, as grease can increase resistance. If the key still doesn't work after replacing the battery, it might be due to a damaged crystal oscillator from dropping the key or the need to re-sync it with the vehicle.
