en
0

Shopping Cart

closeCart
€0.00

How Long Does a Car Key Battery Last? Can You Use a CR2025 Instead of a CR2032?

  • /
  • Blog
  • /
  • How Long Does a Car Key Battery Last? Can You Use a CR2025 Instead of a CR2032?
Post Name
23.06.2025

When was the last time you thought about the battery inside your car key? For most drivers, the answer is probably never—until the key suddenly stops working. A car key battery is a small but essential part of modern driving. It powers keyless entry, remote locking, and in many cases, keyless ignition systems. When the battery fails, it can leave you locked out of your car or stranded in inconvenient situations.

Understanding how long a car key battery typically lasts and knowing when and how to replace it can save you time, money, and unnecessary frustration. In this detailed guide, you will learn how long a typical car key battery lasts, what factors shorten its life, the most common signs that your battery needs replacement, and whether you can substitute a CR2025 for a CR2032 battery in your car key fob.

How Long Does a Car Key Battery Last?

The average car key battery lasts between two to four years. However, the actual lifespan of your key battery depends on several factors, including how often you use the key, whether your car uses a proximity key system, the type of battery installed, the climate where you live, and the quality of the battery brand.

If your car has a keyless entry system or keyless ignition that constantly communicates with your vehicle when nearby, your battery may drain more quickly. Frequent use—such as multiple lock and unlock cycles each day—also leads to faster battery depletion.

What Can Shorten the Life of Your Car Key Battery?

Frequent Use: Keys that are used many times per day will naturally consume more battery power.

Keyless Proximity Systems: Smart keys that communicate continuously with the vehicle tend to use more energy.

Extreme Temperatures: Exposure to both heat and cold can degrade battery performance and lifespan.

Low-Quality Batteries: Cheap, no-name batteries often have a shorter life and can fail unexpectedly.

Many drivers wait for their key to stop working before replacing the battery, but it is recommended to replace it proactively every one to two years to avoid surprise failures, especially before long trips or the winter season.

Signs That Your Car Key Battery Is Failing

Your car key usually gives warning signs before the battery completely dies. Knowing these symptoms can help you avoid being caught in an inconvenient situation.

Reduced Range: You may need to stand closer to your car for the key to work properly.

Delayed Response: The car may not immediately lock or unlock when you press the button.

Intermittent Operation: Sometimes the key works, sometimes it does not.

Dashboard Alerts: Some vehicles display a "low key battery" warning on the dashboard.

Complete Failure: If ignored, the key will eventually stop working entirely.

If you notice any of these warning signs, it is best to replace the battery immediately to ensure continuous, reliable operation.

When Should You Change Your Car Key Battery?

The best time to change your car key battery is before it fully fails. Most experts recommend replacing the battery every two years as preventive maintenance. You should also replace the battery immediately if you notice that your key’s range has reduced or if it sometimes stops working without warning.

Seasonal changes also play a role. During winter, cold temperatures can reduce battery performance significantly, which is why it is wise to replace your battery before the onset of cold weather. Additionally, if you are planning a long trip or vacation, it is a good idea to install a new battery beforehand to avoid potential inconvenience.

Can You Use a CR2025 Instead of a CR2032 Battery in a Car Key?

One of the most common questions drivers ask is whether a CR2025 battery can be used as a substitute for a CR2032 in a car key fob. Although the two batteries are similar in many ways, there are critical differences to consider.

CR2025 vs. CR2032: What Is the Difference?

Both the CR2025 and CR2032 batteries are 3-volt lithium coin cells and have the same diameter of 20 millimeters. However, their thickness and capacity differ.

FeatureCR2025CR2032
Diameter20 mm20 mm
Thickness2.5 mm3.2 mm
Voltage3 volts3 volts
CapacityApproximately 150 mAhApproximately 220 mAh

 

The CR2032 is thicker and has a higher energy capacity, meaning it will typically last longer than a CR2025 in the same device.

Can a CR2025 Fit in a CR2032 Slot?

Technically, a CR2025 can physically fit into a car key fob designed for a CR2032 battery because they have the same diameter. However, because the CR2025 is thinner, it may not make stable contact with the battery terminals inside the key.

Some people attempt to compensate for the thinner battery by adding a small piece of paper, cardboard, or aluminum foil to hold it in place. Although this may temporarily restore functionality in an emergency, it is not a reliable or recommended solution for long-term use.

Should You Use a CR2025 Instead of a CR2032?

The short answer is that using a CR2025 in place of a CR2032 is acceptable as a temporary, emergency solution but is not advisable as a permanent fix. Using the incorrect battery size can lead to poor contact, inconsistent performance, and a much shorter operating life.

Risks of Using the Wrong Battery:

Unstable contact may cause the key to work intermittently.

Lower battery capacity means the key will require more frequent battery replacements.

A loose battery inside the fob can shift during handling, potentially damaging the internal components.

For long-term reliability and to protect your car key from unnecessary wear, it is always best to use the exact battery size specified for your key fob.

Where to Buy the Right Car Key Battery

If you are looking for a high-quality CR2032 battery for your car key, Mr Key offers reliable options from trusted brands such as Panasonic. Choosing a premium battery will ensure your key functions properly for as long as possible and reduces the risk of sudden failure.

Mr Key also provides a wide range of car key shells, key fobs, and accessories compatible with popular brands like Peugeot, Citroën, Nissan, Suzuki, Fiat, Ford, and more. Whether you need to replace the battery, the shell, or the entire key, Mr Key can help you find the right product at an affordable price.

You can browse the full selection in the Mr Key online store and get the parts you need delivered directly to your door.

Car key batteries are often forgotten until they stop working, but with proper care and timely replacement, you can avoid the inconvenience of being locked out or dealing with a non-functional key. Understanding how long a car key battery typically lasts and knowing the signs of failure can help you stay ahead of the problem.

While a CR2025 battery can sometimes be used in an emergency, the CR2032 is the correct and recommended option for most car key fobs due to its longer life and better fit. Using the right battery size ensures that your key works reliably, protects your key's internal components, and provides peace of mind.

Regularly check your key, replace the battery proactively, and always use the correct parts for the best performance. When you need a new battery or key shell, Mr Key is your trusted partner for fast, easy, and affordable car key repairs.

Related Posts

5 Common Car Key Problems and Easy Fixes to Get You Back on the Road
03.07.2024

5 Common Car Key Problems and Easy Fixes to Get You Back on the Road

Losing or encountering issues with your car key can feel like a nightmare, especially when you’re in a hurry. From unresponsive key fobs to stuck keys, these problems are more common than you might think. The good news? Most of these issues have simple, affordable fixes that you can address quickly. This guide will help you identify common car key problems and provide solutions to get you back on track without breaking the bank. 1. Key Won’t Turn in the Ignition Why It Happens: When your car key refuses to turn, it’s often due to a worn-out key, a damaged ignition cylinder, or a locked steering wheel. How to Fix It: Check the Steering Wheel: If the wheel is locked, try gently turning the steering wheel left and right while turning the key in the ignition. Inspect the Key: A bent or worn-out key can cause alignment issues. Try a spare key if you have one. Lubricate the Ignition: Use a small amount of graphite lubricant (avoid oil-based products) to loosen the ignition cylinder. If All Else Fails: Consult a professional to replace the key or ignition lock. Tip: Avoid forcing the key, as this could damage the ignition further. 2. Car Key Fob Isn’t Responding Why It Happens: Modern key fobs are convenient, but they rely on batteries and electronic components that can fail. A dead battery is the most common culprit. How to Fix It: Replace the Battery: Open your key fob (usually with a small screwdriver) and swap out the old battery for a fresh one. Most fobs use coin-shaped batteries like CR2032. Reprogram the Key Fob: If changing the battery doesn’t work, your fob may need reprogramming. Follow your car manual’s instructions or consult a professional locksmith. Check for Damage: Inspect the buttons and internal components for signs of wear or moisture. Tip: Always keep a spare battery on hand to avoid unexpected key fob failures. 3. Key Stuck in the Ignition Why It Happens: This issue often stems from a locked transmission, dirt in the ignition, or a worn-out key that doesn’t align properly. How to Fix It: Ensure the Car Is in Park: For automatic cars, check that the gear shifter is fully in the “Park” position. Clean the Ignition: Use compressed air to remove dirt or debris from the keyhole. Jiggle the Key: Gently wiggle the key while applying light pressure to help free it. Inspect for Damage: If the key is bent, avoid forcing it. A professional can help safely extract it. Tip: If the problem persists, you may need to replace the ignition cylinder or key to prevent further damage. 4. Worn or Damaged Car Key Why It Happens: Over time, constant use can wear down the grooves on your key, making it difficult to start the car or open the doors. How to Fix It: Get a Duplicate Key: If your key is showing wear, have a duplicate made while it still works. Replace the Key: A locksmith can create a new key based on your car’s lock or key code. Upgrade to a Modern Key: If you’re using an older mechanical key, consider upgrading to a transponder key or key fob for added convenience and security. Tip: Don’t wait until your key stops working entirely. Replacing a worn key early can save you time and stress. 5. Key Fob Signal Interference Why It Happens: Sometimes, your car key fob may not respond due to signal interference from nearby electronics or a faulty antenna. How to Fix It: Move Away from Interference: Check for other devices nearby, such as Wi-Fi routers or radios, which may disrupt the signal. Inspect the Fob: Ensure the key fob’s battery is working and the buttons are functional. Reset the Key Fob: Follow your car manual’s instructions to reset or resynchronize the fob. Test the Car’s Receiver: If the problem persists, there may be an issue with your car’s signal receiver. Tip: Parking in a location free from electronic interference can help diagnose if this is the root cause. Preventing Car Key Problems: Simple Tips Taking care of your car key now can save you from bigger headaches later. Here are some quick maintenance tips: Keep Keys Clean: Avoid exposing keys to water, dirt, or chemicals. Store Spare Keys Safely: Always have a backup key in a secure and accessible place. Replace Batteries Regularly: Change key fob batteries annually to prevent unexpected failures. Inspect Your Keys: If you notice wear, cracks, or loose buttons, address the issue early. Why Addressing Car Key Problems Early Saves You Money Ignoring small car key problems can lead to more expensive repairs down the road. For example: A damaged ignition can cost far more to replace than addressing a stuck key early. Reprogramming a lost or broken key fob is more costly than simply replacing a battery. Getting a duplicate key before the original breaks ensures you’re not left stranded. By staying proactive, you can keep your car keys functioning smoothly without spending a fortune.

Here’s 1 Crazy Mistake 40% of Car Owners Make
13.09.2024

Here’s 1 Crazy Mistake 40% of Car Owners Make

When it comes to car ownership, most of us are pretty diligent. We make sure our insurance is up to date, change the oil like clockwork, and even rotate our tires to avoid any wear and tear. But there’s one crucial aspect that many car owners overlook: having a spare key . It seems like a small detail, right? Yet, nearly 40% of car owners don’t have a backup key for their vehicle. And that’s a huge risk. Why? Because losing your only car key can cause a headache you’re not prepared for—and it’s a lot more common than you might think. The Hidden Dangers of Only Having One Car Key It’s easy to get comfortable with just one key. After all, it’s always in your pocket, bag, or hanging on your keychain. But life happens. Keys get lost, misplaced, or even stolen, and when that happens, you’re looking at a nightmare scenario. Here’s why: Costly Lockouts : Lose your key, and you’re locked out of your car, stranded until you can get help. Calling a tow truck or emergency locksmith is not only frustrating but can cost you hundreds of dollars. Inconvenient Delays : Have an important meeting? Picking the kids up from school? With only one key, losing it means your entire day—or week—grinds to a halt. Damaged Key, No Backup : Keys wear down over time, and if you only have one, a damaged key could lead to ignition problems. Suddenly, your car won’t start, and now you’re stuck paying for both a repair and a replacement. Security Risk : Lost keys are more than just a hassle—they’re a potential security threat. If your key falls into the wrong hands, your vehicle becomes vulnerable. The Pricey Locksmith Option Once you’re locked out or your key is lost, your options become limited—and expensive. Going to a local locksmith is one route, but here’s what you’re facing: High Prices : Traditional locksmiths can charge anywhere from €150 to €400 just to cut and program a new car key. Depending on your car model, it could be even more. Inconvenient : Many locksmiths don’t work around your schedule, and waiting for them to arrive or driving to their location takes time you don’t have. The Smart, Affordable Solution: Mr-Key.com Fortunately, there’s an easier and much more affordable option— Mr-Key.com . Instead of paying top dollar and wasting time, here’s how you can get a spare key in just a few simple steps: Take a Picture : Simply snap a photo of your existing key. Send It to Us : Upload the picture to Mr-Key.com using our secure service. Get Your Key Delivered : We’ll cut a perfect match and deliver it right to your door at a fraction of the cost of a traditional locksmith. Don’t Wait for a Crisis—Get Your Spare Key Now! Why risk being locked out or paying hundreds when you can have peace of mind for less? Visit Mr-Key.com today and get a spare car key cut from just a picture. It’s quick, it’s easy, and it’s affordable. Don’t be part of the 40% that gambles with just one key—protect your car and your schedule with Mr-Key.com!

How to Locate Your Key Code for a Replacement
20.08.2024

How to Locate Your Key Code for a Replacement

Losing a key can be a hassle, but the process of getting a replacement becomes much easier if you can locate the key code. The key code is a unique combination of letters and numbers that identifies the specific cut and type of your key. This code is essential for accurately replicating a new key, whether it’s for your car, house, or another type of lock. This guide will help you understand where to find your key code and what steps you can take if the code isn’t easily accessible. Why the Key Code is Important The key code is essentially a blueprint for your key. It tells a locksmith or dealer exactly how to cut a new key that will work with your lock. Without this code, creating a replacement key can be a trial-and-error process, which can be time-consuming and costly. Additionally, for certain types of keys, such as those for cars with transponder chips, the key code is necessary for programming the electronic components of the key. Step 1: Inspect Your Key and Lock The first and most straightforward step is to inspect your key and lock for the key code. For many keys, especially older models, the code is engraved or stamped directly onto the key itself. This is common with car keys, where the code may be found on the metal part of the key blade. In some cases, the code might be on the plastic casing of the key, especially if it’s a newer model with electronic components. If the key itself doesn’t have the code, check the lock. The key code is sometimes inscribed on the lock’s cylinder or on a small metal plate attached to the lock. This is more common with padlocks or specialized security locks. If you’re dealing with a door lock, you might need to remove the lock from the door to inspect it closely. Step 2: Review Documentation and Original Packaging If you can’t find the key code on the key or lock, the next step is to review any documentation or packaging that came with the key. For vehicles, the key code is often provided in the owner’s manual or on a key tag that was given to you at the time of purchase. This tag is usually small and easily misplaced, so it’s worth checking any old documentation or vehicle paperwork you might have. For other types of keys, such as those for padlocks, cabinets, or office furniture, the key code might be printed on the original packaging or on warranty cards. These are often overlooked, but they can be invaluable when you need a replacement key. Step 3: Contact the Manufacturer or Dealer If the key code isn’t visible on the key, lock, or documentation, your next step should be to contact the manufacturer or dealer. Most car manufacturers, for example, keep a record of key codes based on the Vehicle Identification Number (VIN). By providing your VIN to a dealership, they can usually retrieve the key code and either cut a new key for you or give you the information needed to get one cut elsewhere. For other types of keys, such as those for cabinets or padlocks, contacting the manufacturer can also be helpful. Provide them with details about the product, such as the model number and any serial numbers, and they may be able to provide the key code or a replacement key directly. Step 4: Professional Locksmith Assistance If you’ve exhausted all other options, a professional locksmith is your best bet. Locksmiths have specialized tools and knowledge that allow them to decode locks or determine the correct key code even when it’s not visible or available through documentation. They can often cut a new key based on the lock itself, bypassing the need for the original key code entirely. Locksmiths are particularly useful if you’re dealing with older locks, unique security systems, or if the key code is no longer accessible through traditional means. They can also help with programming transponder keys for vehicles, ensuring that your new key not only fits the lock but also communicates correctly with your car’s electronic systems. Additional Tips for Key Code Location Record Key Codes: If you find your key code, make sure to record it somewhere safe. This will save you time if you need another replacement in the future. Ask About Spare Keys: If you’re contacting a dealership or manufacturer, ask if they can provide a spare key at the same time, especially if you’re prone to losing keys. Consider a Key Tracking System: For those who frequently lose keys, consider investing in a key tracking system or a digital key organizer where you can store key codes and important information. Locating your key code is a crucial step in the process of replacing a lost or broken key. By carefully inspecting your key and lock, reviewing any relevant documentation, contacting the manufacturer or dealer, or seeking help from a professional locksmith, you can ensure that your replacement key is accurate and functional. Taking these steps not only saves time and money but also provides peace of mind in knowing that you have a reliable solution for key replacement.

How Hot Weather Can Damage Your Car Key Fob – And What You Can Do About It
19.06.2025

How Hot Weather Can Damage Your Car Key Fob – And What You Can Do About It

When you think about how hot weather affects your vehicle, your first thoughts might go to the engine, the tires, or maybe even the air conditioning. But there’s one small, essential part of your daily driving routine that’s often overlooked — your car key fob. It might seem like a tough little device, but the truth is, it’s far more sensitive than it looks. If you’ve ever left your key fob on the dashboard, in a hot glove box, or even inside your pocket during a heatwave, you may have already caused damage without realizing it. Car key fobs are built with delicate electronics, plastic shells, and lithium coin batteries — all of which are vulnerable to extreme temperatures. In this article, you’ll learn how hot weather affects each part of your key fob, how to spot the early signs of damage, and most importantly, what you can do to protect it. Taking just a few simple steps can save you from the cost and inconvenience of a non-functioning remote, especially when you least expect it. The Plastic Shell: First to Feel the Heat One of the first things to suffer from heat exposure is the plastic casing that protects your key fob. While it’s designed to withstand everyday use — being dropped, tossed in a bag, or handled frequently — it’s not built to survive hours in a baking-hot car. The interior temperature of a parked vehicle can soar past 60 or even 70 degrees Celsius on a sunny day, especially if the key is sitting directly in sunlight. Over time, this level of heat can soften the plastic, causing it to warp, bend, or even split at the seams. You may start to notice that your key doesn’t close as tightly as it used to, or the buttons may feel soft and spongy instead of firm. Cracks might appear along the sides, or parts of the shell may become discolored. While this might seem like a cosmetic issue at first, it has serious implications — a compromised shell allows moisture, dust, and debris to enter the fob, putting the internal electronics at risk. If your key fob’s shell is already showing signs of wear, especially after a hot summer, it’s time to consider replacing the casing before the damage gets worse. Battery Breakdown: How Heat Drains Power Inside your key fob, there’s usually a small lithium battery — typically a CR2032 coin cell. These batteries are reliable under normal conditions, but they don’t respond well to high temperatures. In fact, exposure to extreme heat can accelerate chemical breakdown inside the battery, leading to faster discharge and a shorter overall lifespan. What’s worse, in severe cases, the battery can swell or leak, which can damage the internal components of your fob permanently. If you’ve ever noticed your key fob suddenly stops working or becomes unreliable during the summer, there’s a good chance the battery is struggling under heat stress. The signal may become weaker, you might have to press buttons multiple times, or the remote might stop responding altogether. Replacing the battery is a quick and inexpensive fix, but it’s important to recognize that battery issues are often just the first symptom of deeper heat-related problems. Internal Electronics: Silent Victims of the Heat While the shell and battery are easier to see and replace, the most serious damage often happens silently — deep inside the electronic circuit board. This board, often referred to as the platine, is responsible for all communication between your key and your vehicle. It’s a compact, delicate system of soldered connections and microchips, and unfortunately, it’s not designed to cope with repeated thermal stress. When your key fob is exposed to fluctuating high temperatures, the constant expansion and contraction of materials can loosen solder joints or weaken connections. Moisture that gets trapped inside the shell during humid summer months can accelerate corrosion, especially if the casing is already cracked or loose. The damage might not be immediate, but over time you may find that your key fob becomes unpredictable — sometimes it works, other times it doesn’t, and eventually, it might stop working completely. What You Can Do to Prevent Heat Damage The good news is that most heat-related damage to key fobs is preventable with just a little care and awareness. First, never leave your key fob inside a parked car for extended periods, especially not in direct sunlight. It’s easy to toss your keys into the cup holder or leave them on the dashboard while you run errands, but those few minutes can expose them to dangerous levels of heat. Instead, keep your keys on you or store them in a shaded, temperature-controlled area. If you’re regularly in hot environments — such as driving in warm climates or working outdoors — consider investing in a protective silicone or leather cover. These not only shield the shell from heat exposure but also provide added protection against drops and dirt. You should also make it a habit to replace your battery once a year, even if it seems to be working fine. Batteries weakened by heat can fail suddenly, and a fresh cell ensures your key fob keeps working when you need it most. Finally, if your key fob’s shell is visibly worn or loose, replace it immediately. Many online stores, including Mr Key, offer affordable replacement shells that are easy to install and give your remote a like-new feel. Don’t wait for the damage to reach the internal electronics — by then, repair options are limited and usually more expensive. Protect Your Key, Protect Your Drive Your car key fob might be small, but it plays a huge role in your daily routine. From unlocking doors to starting your engine, it’s a modern convenience we all depend on — until it stops working. And while many drivers are careful with their car’s mechanical systems, few think twice about leaving their key fob in the heat. Now that you know how much damage summer temperatures can cause, you can take the steps needed to protect your key before it’s too late. If you’re looking for high-quality key shell replacements, batteries like the CR2032, or even complete key fobs compatible with your vehicle, Mr Key has you covered. Our online shop offers trusted parts for Peugeot, Citroën, Nissan, Suzuki, Fiat, and more — all designed to help you repair and maintain your car keys quickly and affordably.

Logo
More options Accept all Reject all
This website uses cookies

We use cookies to personalise content and ads, to provide social media features and to analyse our traffic. We also share information about your use of our site with our social media, advertising and analytics partners who may combine it with other information that you’ve provided to them or that they’ve collected from your use of their services.

Chat with us