precisely because a cmos battery is flaking out. Consider that even though your system is relatively new, there is no way to know how long that particular battery sat on a shelf waiting in line for it to finally be grabbed for that system to be built. Since batteries last quite a long time now compared to before, that battery could be three or four times older than the motherboard or other components.
I would start with that replacement since it's the least expensive area to begin with troubleshooting.
I'm getting this error when i turn off, unplug then replug and turn on my system every time - what could it mean?
Also the mobo is quite new, i don't think the cmos battery could be dead yet.