Affirmative.
This is why people have advised you to use a lithium rechargable rather than standard non-rechargable coin cell.
Because with a non-rechargable type, you need to fit a diode.
Fitting it in the right place is a different story. You want it to connect the +5 of the coin cell to the +V supply on the clock chip - AND NOWHERE ELSE.
Otherwise the systerm tries to draw current from the coin cell with no main power, which rapidly exhausts the battery.
A clue - if you fit it (diode) the wrong way around, the clock chip won't remember the time.