It can be incredibly frustrating: you replace the battery in your BMW key fob, thinking it’s a simple fix, only to find it still doesn’t work. You might even be on your second or third fresh battery, just like the author of the original post, and still facing a non-responsive key fob. If you’re searching for a Replacement Bmw Key Fob because of this issue, you might want to hold off for a moment and consider this surprisingly common problem.
Many BMW owners have encountered a similar situation where brand new, seemingly standard CR2032 batteries fail to power their key fobs. In the original poster’s case, they tried multiple new Sony CR2032 batteries, purchased recently and reading over 3 volts on a multimeter, all to no avail. Imagine the frustration of thinking you’ve solved the problem with a simple battery swap, only to be met with continued failure!
The BMW Dealer Dilemma: Expensive Options
Facing a non-working key fob, the next logical step might seem to be a visit to the BMW dealership. However, as the original post highlights, this can quickly become an expensive endeavor. The BMW San Francisco service advisor presented the author with options that were less than ideal:
These options presented a hefty bill, ranging from $660 to a staggering $1100! Suddenly, the idea of a simple battery replacement is a distant memory, replaced by the looming cost of a potentially unnecessary replacement BMW key fob and expensive diagnostics. The author even considered a Bimmertech key fob as a potentially more affordable alternative at $485, highlighting the desire to avoid the dealer’s high prices.
The Unexpected Solution: The BMW Battery
In a moment of perhaps slightly desperate experimentation, and on the advice of the parts department, the author tried a BMW branded CR2032 battery, costing just $9. And surprisingly, it worked! After struggling with multiple aftermarket batteries that seemed perfectly fine, the official BMW battery was the key (pun intended) to resolving the issue.
The parts specialist at the dealership revealed a crucial piece of information: this is a common occurrence. He stated that he sees customers coming in at least once a month with the same problem – new, non-BMW batteries failing to work in their key fobs, while the BMW battery solves the issue instantly.
Voltage Readings and Battery Mysteries
The situation becomes even more perplexing when considering battery voltage. The original battery, which was still partially working, read 2.9 volts. The new Sony batteries, which failed to work initially, read 3.1 volts. Interestingly, one of the Sony batteries that initially failed later worked, but its voltage had dropped to 2.7 volts!
This experience suggests that voltage alone might not be the only factor determining a CR2032 battery’s compatibility with a BMW key fob. There might be subtle differences in internal resistance, current delivery, or other factors that make BMW key fobs particularly sensitive to battery brand.
Key Takeaway: Try a BMW Battery First
Before you jump to conclusions and assume you need a costly replacement BMW key fob, or expensive diagnostic services, take a page from this experience. Invest the $9 in a BMW branded CR2032 battery. It might seem counterintuitive, especially if you have new batteries already, but it could save you hundreds of dollars and a lot of frustration.
While the logic behind why some aftermarket CR2032 batteries fail while the BMW battery works remains unclear, the anecdotal evidence is strong. If your BMW key fob is unresponsive after a battery change, before considering a replacement BMW key fob, make the surprisingly simple and affordable move of trying a battery specifically from BMW. It could be the only “replacement” you actually need!
