I found a solution. I opened the back panel of the Dell XPS 13 9310 and unplugged the battery for a few minutes and plugged it back in. After closing the panel and booting the laptop, there seem to be no battery issues anymore.
Within the past week, the diagnostic LED on my XPS 13 9310 started flashing--amber three times and white once. I looked up what this meant and identified the issue as a CMOS battery failure. The problem is that the CMOS battery in a XPS 13 9310 isn't a coin battery that I can simply replace. I read somewhere that the CMOS battery is actually built into the main battery, but I'm not sure if this is true. Since then, the diagnostic flashing became more frequent and now it is constantly flashing amber. Also, my laptop doesn't charge anymore, but the battery doesn't seem to drain its charge as long as the charger is plugged in. If the issue is only with the CMOS battery is there a way to simply replace that, or do I have to completely replace the battery?
XPS 13 9310 CMOS battery failure