If you’re a Hyundai owner, you rely on your key fob daily to access and secure your vehicle. Like any electronic device, the key fob is powered by a battery, and eventually, you’ll need to replace it. Understanding what kind of battery your Hyundai key fob takes is crucial for ensuring you can easily replace it when the time comes. This guide will provide you with all the essential information you need to know about Hyundai key fob batteries, ensuring you’re never caught off guard by a dead fob.
Hyundai key fobs typically use coin cell batteries, also known as button batteries. The most common types are CR2032 and CR2025 3V lithium batteries. These batteries are small, circular, and flat, resembling a button, hence the name. While both CR2032 and CR2025 batteries are 3V and 20mm in diameter, they differ slightly in thickness. The CR2032 is 3.2mm thick, while the CR2025 is 2.5mm thick. Generally, Hyundai key fobs are designed to use CR2032 batteries, which offer a slightly longer lifespan due to their greater capacity. However, in some cases, a CR2025 might also be compatible. It is always best to check your Hyundai owner’s manual or the markings inside your key fob to confirm the exact battery type required for your specific model.
Alt text: Close-up of the battery compartment inside a Hyundai key fob, highlighting the battery orientation markings.
One important point to remember when replacing your Hyundai key fob battery is the battery orientation. Before removing the old battery, carefully note the position of the positive (+) and negative (-) terminals. Some Hyundai owner’s manuals have been known to have errors in their diagrams, so relying solely on the manual might be misleading. A common mistake is inserting the battery with the positive side facing up, as indicated in some manuals, which will prevent the key fob from working. The correct orientation is usually with the negative (-) side facing upwards. If you’re unsure, take a picture of the battery orientation before removing the old one to ensure you insert the new battery correctly. Incorrect orientation won’t damage the fob, but it simply won’t function.
Alt text: A CR2032 3V lithium battery, the common type used in Hyundai key fobs, shown with voltage and chemical composition clearly visible.
Regarding battery life, you can typically expect a Hyundai key fob battery to last around 2 to 3 years. However, this lifespan can be influenced by several factors. “Smart” or proximity key fobs, which allow for features like keyless entry, puddle lights, and automatic trunk opening when you are nearby, tend to drain batteries faster. This is because these fobs are constantly transmitting a low-power radio frequency (RF) signal to communicate with your vehicle, even when you are not actively pressing any buttons. This continuous “proximity power” signal is what allows your car to detect your presence and enable those convenient features. When you press a button on the fob, the RF power increases, extending the range for functions like locking and unlocking from a distance. Non-proximity key fobs, on the other hand, generally have longer battery life because they only use RF power when a button is pressed.
Another factor that can impact key fob battery life, and even your car battery, is parasitic drain. If you routinely store your smart key fob too close to your vehicle, for example, inside your house near the garage, the constant communication between the fob and the car can keep the car’s system “awake.” This continuous activity creates a parasitic draw that can drain both your car battery and your key fob battery prematurely. To avoid this, it’s advisable to store your key fob at a distance from your vehicle when you are at home, ideally outside of the vehicle’s reception range.
Finally, when testing your key fob battery with a voltmeter, be aware that a fresh CR2032 or CR2025 battery should measure around 3.3VDC, not just the 3VDC marked on the battery. If your voltmeter reading is below 3VDC, even if it’s “about” 3VDC, the battery is likely depleted and needs replacement. Keeping these points in mind will help you maintain your Hyundai key fob and ensure it’s always ready when you need it.
