My Timex indiglo wr30m had a CR 1216 battery replaced. The watch now lights up but the clock doesnt work. there is only one battery in watch. Am I using correct battery?

SOURCE: Can't get the back plate of a Timex Indiglo WR30M watch back on

To open watch case, hold back of watch up with arrow pointer on the back plate pointing to the right. There is a pry point on the upper edge where you will see a small arrow pointing. Use a small flat end screw driver to pry the watch case open. Be sure to replace the back the same way with the arrow pointing away from the setting knob.
Take a 1-1/4 inch paddle bit and drill a hole in a 1-3/4 inch wide piece of wood about 1/8 inch deep. Then take another piece of wood about 2 inches long by 3/4 inch thick by 1 inch wide to lay across the back of the case plate. Place the crystal of the watch in the drilled hole. Used a vise or clamp with the watch between the two blocks of wood to press the back on. Be careful not to over press. Works great

SOURCE: timex watch battery

depends on where you buy them and the brand they can range from 1 dollar on sites such as ebay or 2.99 at stores such as walgreens or cvs (drugstores) or walmart, battery plus etc.