> For the complete documentation index, see [llms.txt](https://qudelix.gitbook.io/home/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://qudelix.gitbook.io/home/general/charger.md).

# Charger

**About chargers and power supplies**

Devices that are commonly referred to as “chargers” are technically **power supplies**.\
A power supply provides a fixed voltage and defines the **maximum current** it can deliver.\
For example, USB ports on a PC can support different maximum current levels depending on the port type, such as 500 mA, 900 mA, 1.5 A, or up to 3 A.

However, the connected device does **not automatically draw the maximum current** available.\
Instead, the **receiving device controls how much current it draws**, effectively regulating the current flow according to its own requirements.

A **charger**, in the strict technical sense, is the circuit that controls the voltage and current delivered **to a battery**.\
This charging circuit is usually **built into the device itself**, such as in smartphones or portable audio devices, which is why it is often referred to as a **built-in charger**.

The built-in charger continuously manages the charging process by adjusting the current supplied to the battery.\
When charging is required, it allows current to flow; once the battery is fully charged, it stops the current flow to prevent overcharging.