Battery issue with the paperwhite signature edition

Ok so after really thinking about it I bought my first kindle on Black Friday. I decided to go for the new paperwhite signature edition and I’ve seen that previous generation of the kindle had great battery life and this one was supposed to be even better. The battery only seemed to last about 2 weeks with no charges in between. So I contacted Amazon and I got a replacement issued and with the replacement the battery last maybe a week and a half! I charged it on the new year when I got it and it’s the 8th and I’m at 19%. Am I just really unlucky or is this a common issue?? And I’m hesitant to ask for another replacement, if they’ll even authorize that, because it seems the battery is getting worse!