The installation of a photolumiescent FPEEPMS will be performed in accordance with an STC. The STC will contain operating procedures (including initial charge time for the first flight of the day) and where these procedures are to be located. Often, the STC specifies the AFM.
As each aircraft configuration and installation is different, the charging time and procedures may also vary between airlines. I have seen system charge times ranging from 10 minutes up to 60 minutes. For this reason, you should rely upon the information in your company's publications, which should in turn be based on the information from the STC.
Some additional, general information may be found here:
AC 25.812-2 Floor Proximity Emergency Escape Path Marking Systems Incorporating Photoluminescent Elements
FSF Cabin Crew Safety - Photoluminescent Escape-path Marking Alters Few Duties of Flight Attendants
STG Aerospace - The harmonisation of protocols and standards for high-performance photoluminescent way guidance systems in commercial aircraft; A technology review paper