Typically, it means faster charging speeds and bi-directional charging. Dell The more USB ports on a device, the better, but things can get confusing when they all have a different symbol on them. Among the markings seen next to USB ports, it's not uncommon to see a battery icon, which typically indicates that it's a USB Power Delivery port. Known as USB PD for short, this port means it can deliver higher power levels than a typical USB port, but can also charge connected devices.
The USB PD charging protocol has a long history and was first introduced in 2012, meaning it predates the debut of the USB-C port. However, USB PD was updated in 2021 and is now able to deliver up to 240W of power, meaning it can support more demanding devices like high-end laptops or some monitors.
When you see a battery symbol next to a USB port, it can mean a few things. Most commonly, the icon means that port is USB PD compatible and can offer a more sophisticated charging protocol. Using USB PD, you can charge your laptop faster since Power Delivery conducts an intelligent digital handshake between device and charger. The battery symbol could also translate to bidirectional charging, allowing you to charge another device like your smartphone or Air Pods. Some laptops' USB ports with this symbol can charge a device even when it's asleep or shut down thanks to "Always On" charging.
As much sense as a battery icon makes, USB PD has somewhat of an identity crisis when it comes to the symbol that represents it. According to the USB Implementers Forum, the official symbol is a battery shape made with negative space. Members include Apple, Microsoft, and HP, but not all companies align with how they indicate that a USB port is equipped with Power Delivery. Across devices, there can be the official battery symbol, a different battery logo, a lightning bolt, or simply the letters "PD". If in doubt, it's best to check the manufacturer's specifications.
Source: Engadget · Summarized by HeadlinesBriefing