It's almost a year old. Should be FHS not 4k. The battery issue has always been a problem. I just thought I'd finally try to tackle it now that the warranty is expiring. I see a lot of people have this issue. It seems like the answer is to never buy a Dell again since they don't stand behind their products.
Maybe its just software issue (you got some power draining process running in the background). Consider resetting your device to factory state, run windows update, do not install nothing else than webbrowser and some security apps (firewall, antivirus - download form official site, not from setup files that you may have on you disk; or at least some script blocker like uMatrix for browser) and verify how long it will last. If more than previous it will mean that you found the issue if no - it might by crappy battery or some other hardware problem.
If you decide to test your device in that way: do not open any files, photos, apps that has been present on your drive before this reset. Do not connect any external devices, phone, usb-drives etc. (something may be infected and for test purposes it would be good idea to exclude/isolate such scenario).
You can also try to "reset battery memory" - discharge it until notebook won't turn on, charge it full, unplug the charger and repeat this process couple of times. If battery is constantly charged (i mean your AC charge even on 98%) it might forgot where min/max is (it less common nowadays since circuits are "smarter" and cells better, but might be worth a shot).