Have you ever replaced the battery in your BMW key fob, only to find it still stubbornly refuses to work? You’re not alone. Many BMW owners encounter this frustrating issue, even after installing fresh, seemingly compatible batteries. One BMW driver recently shared their perplexing experience, highlighting a common yet often overlooked solution that could save you hundreds of dollars and a trip to the dealership.
The Battery Replacement Dilemma: When New Isn’t Always Better
The story begins with a familiar scenario: a BMW key fob throwing an error message, signaling it might be time for a battery change. Armed with new Sony CR2032 batteries, purchased just months prior and reading a healthy 3.1 volts on a multimeter, our driver confidently swapped out the old battery. Frustration quickly set in – the key fob remained unresponsive. Even a second, unopened battery of the same type failed to bring the key fob back to life.
A BMW key fob with its battery compartment open, highlighting the CR2032 battery type, in a context discussing troubleshooting key fob battery issues.
BMW Dealership or Bust? Exploring Costly Options
Facing a non-functional key fob despite battery replacements, the next logical step seemed to be a visit to the BMW dealership. The service advisor presented a tiered approach, starting with trying a genuine BMW CR2032 battery for $9. If that failed, a $458 diagnostic on the remote was proposed, potentially followed by a $650 key fob replacement – in addition to the diagnostic fee! Alternatively, skipping the diagnostic and going straight to a new remote for $650 was also on the table. Suddenly, a simple battery issue could escalate to a $1100 problem. The prospect of a $485 aftermarket key fob from Bimmertech (https://www.bimmer-tech.net/category-bmw-key-fob) started to look considerably more appealing.
The $9 Solution: Sometimes, Brand Matters
Before committing to expensive diagnostics or replacements, our driver decided to try the $9 BMW-branded CR2032 battery. To their surprise, and relief, it worked instantly! Talking to the parts department, they discovered this wasn’t an isolated incident. The parts specialist mentioned seeing customers encounter this exact problem – aftermarket batteries failing despite being new – at least once a month. It turns out, despite reading the correct voltage, the aftermarket batteries were the culprit. The original battery, even when reading a lower 2.9 volts, had still been functional. Further testing revealed even more inconsistencies: another new Sony battery, reading 3.0v, surprisingly worked, while the initial 3.1v battery inexplicably dropped to 2.7v after being removed.
