Dell - hardware configuration

Hey there, I'm currently running an HP Pavilion 15
and you can check out the full technical specs right here http://www.acer.com/ac/hr/HR/content/model/NX.GA4EX.004

I'm looking to bump up my memory by either 4 or 8 gigs, but I've been having a hard time tracking down the exact specs of the RAM currently installed—specifically the frequency and the manufacturer—since nothing seems to pop up in my searches.
I’d really rather not crack the case open unless it’s absolutely necessary to get this upgrade done, so if anyone happens to have those specific details handy, I would truly appreciate it if you could share them.

P.S. Do you think I'll run into any compatibility issues if I decide to go with an additional 8 gigs, considering there's already a single 4 gig stick inside?

According to the Corsair RAM advisor (which is about 99% reliable), you've got 4GB of DDR3L 1600MHz sitting in there. This laptop has two slots and can handle up to 16GB total if you go with two 8GB sticks. Just run HWMonitor or Speccy and you’ll know exactly what kind of memory you're working with for sure.

It doesn't matter if the new RAM isn't from the same manufacturer. In this day and age, incompatibility issues between different brands are pretty much unheard of. The only thing that actually matters is that you get DDR3L (1.35V), not the standard DDR3 (1.5V).
http://www.amazon.com/s?k=ddr3l+so-dimm+8gb

Much appreciated