Smart Fortwo Key Battery Replacement Fix & Tips

Had the same issue last week with my 2016 Smart EQ ForFour. The key fob started acting inconsistently, showing battery warnings before completely failing to unlock the doors. The problem was simply a dead key battery. Key fob batteries typically last 3-4 years, so this is normal maintenance rather than a serious issue. The battery replacement process is straightforward: 1. Look for a small notch on the key fob 2. Carefully separate the fob housing using a flat tool 3. Remove the old CR2032 battery 4. Insert new battery matching positive/negative orientation 5. Snap housing back together 6. Test all functions Important: After car key battery replacement, you might need to press the unlock button a few times to resync the fob with your car. If the key still fails after installing a fresh battery, then it could indicate a more complex issue with the keyless entry system or the fob itself. Most auto parts stores carry the correct fob battery. No specialized tools needed for this fix, unlike my previous Smart repairs.

Thanks for sharing your experience. My smart car had similar problems and I was worried about expensive repairs. Ended up being just a basic key fob battery issue like you described. Would be helpful to know what you paid for the battery replacement and if youve had any other key problems since fixing it. The CR2032 batteries I see in stores have quite different prices and Im not sure which brand to trust for my auto key. Did you need to do any special programming after changing the car key battery?

Thanks for asking about the follow-up. The key battery low warning completely disappeared after getting it fixed at the shop. The total cost was 37€ for the fob battery replacement, which included a quality CR2032 and labor. No special programming was needed after the battery replacement, the key fob worked right away with the new battery. Just had to press the unlock button once to sync it back up with the car. The keyless entry system has been working flawlessly since then. For choosing batteries, I would recommend getting the fob battery replacement done by a professional rather than trying different store brands. The peace of mind is worth the service cost, especially since a poor quality battery could fail early and leave you stranded. No other key-related issues have come up in the months since fixing the low battery warning. The key fob is working just as good as new now.

Thanks everyone for the help. I went ahead and took my car to a trusted mechanic. The key fob battery replacement cost me 42€ total. The shop used a premium battery brand and the whole service took about 15 minutes. No programming was needed, just pressed the unlock button twice and everything worked perfectly. Such a relief it wasnt a major issue with the keyless entry system. The dead key battery warning is gone and the fob works like new again. Much better experience than my last car repair. Glad I asked here first instead of worrying about expensive fixes. Will definitely keep track of when I might need the next key battery change to avoid any surprises.