He is not listed on the Alabama Civil War Service Database.
"On Feb.8, 1862, a fourth company (Co. D) was added [to the 5th Battalion]. The Daniel Boone Rifles from Mobile County, AL (formerly Co. K, First Confederate [Tennessee] Infantry Regiment, Provisional Army.) This company was disbanded on May 22nd, 1863 and its members were transferred to the other three companies of the battalion." Info found at history-sites.com/~kjones/alinfo.html
Fold3 lists Fifth Battalion, Volunteers, Powers, John but I can't access the records because I am not a member.
I would also appreciate it if someone can check the 1860 Mobile Co, AL census for John or John M. Powers with wife Adeline, daughter Mary Elizabeth "Mollie" and son James.