[bensanford]

I was repeatedly having problems with the small battery in my key fob of my F22. It seemed that every few months I would get the "low battery" warning when I got in the car and would need to replace the battery.

I think I finally found the cause of this problem. Evidently, the key fob is very picky about the brand or manufacturer of the battery. I had two brand new CR2450 batteries - which both read about the same on a digital voltmeter. But one brand works perfectly, and the other had problems.

I attached a photo of the two batteries. The one on the left works fine, the one on the right has problems.

I had noticed a similar problem when replacing batteries in Apple AirTags. Apple noted that some batteries with bitterant coatings "might not work with AirTag." The coating is intended to make the battery taste bad so small children won't eat them. Perhaps a similar issue is happening in the key fobs and coated batteries.

[MarcoZandrini]

There are a ton of counterfeit batteries out there. I replaced the batteries in my fobs and there were dead 3 days later. Bought them from Amazon . I use copper top batteries that I buy locally. They see to work fine.

[Kernel Kurtz]

Originally Posted by MarcoZandrini

There are a ton of counterfeit batteries out there. I replaced the batteries in my fobs and there were dead 3 days later. Bought them from Amazon . I use copper top batteries that I buy locally. They see to work fine.

Yeah, I use Amazon a lot, but not for batteries. For important stuff that use coin cells (key fobs, garage remote, PC CMOS, firearms sights, etc) I pay the premium and buy Energizer or Duracell locally. Cheap ones are OK for the bathroom scales and such.

[rob_f22]

I was at BMW for this same issue and the sales guy (when I was picking up a replacement key) gave me a spare one they had for BMW keys lying around. He told me the batteries are really specific and you should really get them from BMW to guarantee that they work. I’m sure they’re marking up some certain brand as their own but you can guarantee it works if it’s from the dealer.

[Ajowhan]

Having the same issue as well lmao, Looks like we all bought from the same place, Amazon...

My current battery dont even trigger the battery low warning anymore but the key is barely working..