Place it at the end of a phone-failure gag, after the setup has made the dying battery clear, then follow it with a classic error sound to underline the shutdown. A discord notification works earlier in the same edit to set up the phone theme before the warning arrives.
Über diesen Sound
This is the short low-battery alert used by SKY Vega phones between 2010 and 2016, a brief electronic warning tone lasting under a second. It feels urgent and slightly nagging, like a phone demanding attention before it shuts down. The Type 3 version was one of the alerts built into those handsets for a dying battery.