Welcome, Yonian!
From your post, it sounds like you are working on locating the missing battery icon from your Menu Bar on your Mac. We’re glad that you reached out to the Apple Support Communities. We want to try and help get you pointed in the right direction. We see no one has responded to your post yet. Here are a couple of things that might help others answer your question:
Check out this link to learn more information about your MacBook battery: Get help with your Mac notebook battery. Also, try to uncheck "Show battery status in menu bar" then restart your Mac. Once that has been restarted, go back into the Battery settings and re-check "Show battery status in menu bar." Does that help to correct the issue?
Does the issue happen with a specific user? If you do not have an alternate user, you may need to create one for testing purposes. Here's more information on that process: Set up users, guests, and groups on Mac.
Take care!