Yes. They use watch batteries.
One reason that your remote key will not unlock your Mazda 6 is that a fuse is blown. You may need to replace the batteries in the remote or reprogram the remote. A bad body control module is another reason the remote will not unlock the doors.
it takes two 3V CR 1620 batteries
Usually you change batteries when it dies out on you. But there are also indications that batteries need changing. Like it's not working smoothly, or remote signal seems weak, or the flashing battery indicator. Best if you have a spare set of batteries on hand.
check the batteries of the key remote if else check the fuse below steering column.otherwise seek the help of help line .
SwatchBattery has a lot of coin type batteries. http://swatchbattery.com/ . My 2002 300M remote uses a CR2016 (3volt) battery which they carry.
two things replace the 2 batteries inside the key ( IT'S THE ONE THAT LOOKS LIKE A QUARTER ) you are out of range
It means your car gets low signal of the remote control ( key ), you have to change your key's batteries and the problem will be solved :)
Walmart or any place that sells small batteries for watches or calculators.
I presume you've changed the batteries? If the batteries are good I don't know what to tell you dude, might need a new one.
Open it up and you will find out.