Not sure haven't had that problem yet I'm sure you can get a battery for key for about $10 or less call service and ask my best advice I'm sure you get battery at Walmart for that.
Look in your own your owner's manual find out what battery it takes go to Walmart can't cost more than 2 or 3 dollars at Max. If you need help go to Batteries Plus out in town center and they'll replace it for you and again it probably won't cost over $5
Try batteries plus in Sherman
Like Raymond said, it's the battery not the FOB. The fin pops apart and you replace the battery there. Easy as pie... You can do it!
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