I was arrested for battery but not charged or convicted. Now I'm apply for a police position. Will it show up on my background check.. david

First its not a good idea to piggyback your question on another thread. This can lead to confusion. So I've moved your question to its own thread.

It probably will be found, since the police will do a more thorough check. So you should mention it on the application.

Yes if you are applying for a job with the police, normally they ask, were you ever arrested, even if not convicted.

And yes while it may not show up on the NCIC report, (if in US) but it is possible to be found

It should not stop you from getting the position, as long as on the application, you are honest, if it asked for convictions, then it is still no, if asked for arrests, even if not convicted, you answer honest