Current Limiting

What Happens When a Charger Cannot Supply Enough Current

A charger’s current rating is a capacity limit, not a fixed amount of current that it forces into a device. A 5 V, 3 A supply does not continuously push 3 A into every connected load. The load draws current according to its circuitry, while the source must keep its output within specification up to the current it is designed to provide. The interesting case begins when the device would benefit from more power than the source can supply. Depending on the charger, cable, charging protocol, and device power-management circuit, the result can be slower charging, reduced input voltage, source shutdown, repeated reconnects, or battery discharge even while the charger remains connected.