Key fobs are indispensable for modern Subaru vehicles, providing convenient access and security features. A crucial component of these fobs is the battery, typically a small, coin-shaped lithium cell. Owners often wonder about the lifespan of these batteries and what factors contribute to their depletion. While there might be misconceptions about air exposure being the primary culprit, the reality is more nuanced, revolving around humidity and temperature changes. This article delves into the factors affecting the battery life of your Subaru key fob, providing insights to help you understand and potentially prolong its functionality.
It’s a common assumption that air exposure might be detrimental to lithium batteries, leading to questions about why they aren’t always hermetically sealed. If air were the main issue, then batteries like CR123, AA, and AAA, which are commonly packaged in open-air blister packs, would also suffer significantly. These batteries, often more expensive than button cells used in key fobs, are not typically sealed in airtight packaging, suggesting that direct air exposure isn’t the primary cause of degradation in this context.
The longevity of your Subaru key fob battery is more closely tied to environmental factors, particularly humidity and temperature fluctuations. Lithium coin cell batteries, like the CR2032 commonly found in key fobs, do experience self-discharge over time. This process is accelerated in environments with higher humidity levels, especially above 75%, a condition prevalent in many regions, particularly during warmer months without consistent air conditioning. Studies and tests on CR2032 batteries indicate that discharge, transient shorts, or corrosion leading to discharge are more likely to occur and intensify in such humid conditions. The repeated exposure to drastic temperature and humidity changes that key fobs endure within vehicles likely contributes significantly to the early depletion of their batteries.
Manufacturers often guarantee a shelf life for these batteries, sometimes up to 10 years, and some are even double-sealed for extended storage. However, it’s important to differentiate between shelf life and the operational life once the battery is in use within your Subaru key fob. While packaging might offer protection during storage, the real-world conditions of daily use expose the battery to temperature variations and humidity.
Furthermore, the packaging of button cell batteries has evolved significantly, particularly concerning child safety. Modern child-resistant packaging is primarily a safety measure to prevent accidental ingestion by children, driven by safety standards and regulations. While effective for safety, this packaging is not fundamentally designed to enhance battery preservation from environmental factors like humidity. The shift towards more secure packaging was significantly influenced by industry leaders prioritizing child safety, prompting competitors to follow suit. Despite these advancements in safety packaging, many common blister packs still prioritize cost-effectiveness, sometimes at the expense of user-friendliness when trying to access a single battery. However, upcoming regulations are expected to further standardize and enhance safety requirements for button cell battery packaging.
In conclusion, while the idea of air exposure damaging your Subaru key fob battery might seem plausible, humidity and temperature changes are the more significant culprits affecting battery life. Understanding these factors can help Subaru owners appreciate the typical lifespan of their key fob batteries and perhaps take steps to mitigate extreme temperature exposure where possible. When your Subaru key fob battery eventually needs replacement, knowing it usually utilizes a CR2032 battery will ensure you can easily find a replacement and keep your key fob functioning reliably.
