Not too sure of your question. But correct or not will depend on the sentence.
The battery is charged. = correct.
Yes - in America! Don't say it in Australia, where it means something else entirely.
In many respects Wikipedia is an extraordinary reference, but the say 'everything there is correct' is entirely too blanket.
No. The correct way to say that you disagree with something would be "in disagreement."
no it is not correct to say you are not for sure instead you can say in proper English that you are not sure about something
It would be more normal to say "bored with something"
You should say that something is placed.
the correct way to say it is both of them cause they both make sense...
You can say feliz groundhog dia!!! it might not be entirely correct but they'll understand what your are saying
Say, "Thank you."
Yes assuming you are about to say a company that does something.
Not entirely, no. It'd be better to say "there's a pain in my legs". To say "my legs are painful", is to say "my legs can hurt people", pretty much.
It depends what you are saying. For example, it's correct to say this: "Walk in a straight line unless otherwise directed". It is not correct to say something weird like "Well call me unless otherwise you don't want to" or something. But it can be done.