like the battery status of my laptop in OH?
Where is your openHAB instance running from?
If from the laptop you are trying to get the information from the systeminfo binding will help.
OH is installed on another computer, Windows 10
Well you can use the REST API from openHAB to publish the battery value. Of course you need a small script/tool on your laptop that periodically pushes the battery state to your openHAB instance.
You can also use some tool that supports MQTT.
Basically there are tons of options, I think with the REST API you will succeed the fastest.
Which script / tool to look for?
I do not know where to find them
Have a look to the document that is linked before your post.
It has examples in how to use the REST API.
On your computer ( windows ) that delivers the value you would like to see in OH you need e.g. to run curl.exe or wget.exe.
In case you are familiar with powershell this of might be an other option as you should be able to get the laptops battery value via powershell call, too.