I have a laptop and it beeps when I think I put the battery in. Why is he doing this
There can be different reasons for this.
How does he beep? (So number, length, possibly pitch of the tones)
In addition, your BIOS would be relevant (can usually be found out on the Motehrboard.
With both, you can then evaluate the beeps (if they are BIOS beep codes) and find out why your PC beeps.
I'm just a little afraid because if I run the battery now nothing will happen because the battery is empty. If I want to open it up, something can happen
Nothing works without electricity. And unless you have poured some water over your PC or something similar, nothing should happen if you charge the laptop with a charging cable. At least it shouldn't break anymore.
