Why does my clock stay lit when key is off, draining battery?

 

Did it just start doing this?
Some of them DO stay in 24/7.
If it a recent thing, try disconnecting the negative (black) battery cable, then the positive (red) cable & let it sit for about 15mins.

Then, connect the positive first, then the negative back to your battery. & try to make sure you don't get sparks.
(I don't know if it will work, because some of those clocks DID stay on 24/7.
Unless it drains your battery, then it shouldn't be a problem. :-)