Configure Keyboard Backlight Timeout on Inspiron 15 7000 Gaming laptop

A long time ago I solved the issue of the backlighting fading off after a few seconds. I managed to get it to stay on. Unfortunately something in my system has changed and the settings have reverted. Now, the backlighting goes off after a few seconds. I have been into the BIOS and there is no option to keep it from switching off that I can find. I am in lowlit environment all the time and need the keyboard to be lit permanently. Please will you explain to me how I can set this.