Unless you recall a few years ago, Nexus 6P owners announced their phone issues shutdown well before a dead battery was confirmed by the system. Now, when on low battery, some Pixel 3 owners report similar early shutdown issues on their devices.
Posts from numerous Pixel 3 and Pixel 3 XL owners who are experiencing similar issues have been spotted by Android Police over the past few months. The general problem here is that devices shut down before they hit 0%, specifically between 20% and 40%.
In some situations, when under this total the device will shut down randomly, but on others, after reaching the halfway mark, it will trickle down quickly. The only advice Google gives to users experiencing this problem is to reboot into safe mode or restart a factory. The problem is still protected under warranty for many users meaning replacements are available.
This early shutdown issue on the Pixel 3 series does not appear to be almost as widespread as it was on the Nexus 6P, but it is still a very frustrating issue to see. Google has recently been sued on the Nexus 6P in connection with this problem, so hopefully the company can learn from it and offer a better solution to affected Pixel owners.