5 beeps is generally an indication of a CMOS battery problem. And considering that the system sat in a box for 6 years (did I read that correctly), entirely possible. That procedure is here in the owners manual. A video is here showing the procedure and the part is available here and here.
Purchased Inspiron 11 3162 six years ago, finally took it out the box and turned it on, now it won't stop beeping - five beeps.  Otherwise it works just fine.  The only time it won't beep is if I turn off the laptop OR if the audio is being used, like if I'm listening to something on youtube.  I have to play a looped song so it won't beep.  As soon as the music ends the beeping continues again.  I have to constantly play music on my laptop, usually on mute so it's not distracting, just to temporarily stop the beeping.  Also, when I turned on my laptop, the beeping is much louder momentarily, sounds like a smoke detector alarm for about a minute, then it's not as loud.  Anyone have suggestions?  
Inspiron 11 3162 - won't stop beeping