I buy _all_ of my coin cell batteries from Digikey. Yeah, it takes some foresight and planning sometimes, since they can only be shipped UPS ground, but they a

I buy _all_ of my coin cell batteries from Digikey. Yeah, it takes some foresight and planning sometimes, since they can only be shipped UPS ground, but they are cheap, come in bulk, and Digikey certifies that they are genuine.