Where is the CMOS battery?

My system clock keeps on delaying compared to the actual time.

Is there a repair?

I also noticed that it may be caused by the CMOS battery starting to fail.

I have opened the device up and am comfortable, as I replaced the mSATA myself.

However, I don't really know where the CMOS is.

Where is it? Thanks

Tried to locate it in the area, but it looks like it isn't really there.

It's only cables that connect the circuit board.

Also, I purposefully disconnected this part that is mentioned in the instructions for motherboard replacement and speaker replacement. The computer turned on and wifi was completely functional with it disconnected. What is it for?