The main laptop charger connector types are round DC barrel plugs, USB-C and brand-specific rectangular or magnetic plugs. To replace a charger, match the laptop model and its power requirements as well as the plug. A connector that fits is not automatically the right charger.
What are the main laptop charger connector types?
The round laptop charging plug is commonly called a DC barrel connector. Other laptops use a connector specific to that brand, or a USB-C port that supports charging. The name tells you the connector family; you still need the exact fit, voltage, polarity and power requirements.
| Connector type | What to compare |
|---|---|
| Round barrel connector | Outer diameter, inner diameter, insertion length and any centre identification pin. |
| Brand-specific rectangular or magnetic connector | The manufacturer’s model-specific part number and compatibility list. |
| USB-C | Whether the laptop port accepts charging, the supported power profile and cable rating. |
A single brand can use several connector sizes. Do not choose a charger from a brand-only table, and do not force a nearly matching plug into the port.
What is the round laptop charger called?
It is usually a DC barrel plug. Sizes vary, and some have an extra centre pin. Two round plugs can look almost identical yet have different inner diameters, lengths or identification systems.
Lenovo‘s rectangular connector is often called Slim Tip. For example, Lenovo’s Slim Tip adapter page distinguishes it from older round barrel plugs. Still check the exact model’s required power; the connector name alone is not a complete compatibility check.
Is the wall cable the same as the laptop charging plug?
No. A detachable cable between the wall and the power brick carries mains power. The connector between the brick and the laptop supplies the power specified for the computer. Identify which part you need before buying a replacement.
Read the original adapter label
- Output voltage: for a fixed-voltage barrel adapter, use the laptop manufacturer’s specified voltage.
- Polarity: the positive and negative arrangement must match. A barrel connector’s shape does not prove polarity.
- Current and power: the adapter must meet the required capacity and compatibility specification.
- Identification: some systems check the adapter electronically; a matching voltage and plug may still produce a warning.
Power in watts equals volts multiplied by amps. For example, 20 V × 3.25 A is 65 W. Use this calculation to read a label, not to decide that any 65 W adapter will work.
Read Output, not just Input
The adapter’s Input line describes the supply from the wall. Its Output line describes the power it provides to the laptop. For a fixed-voltage charger, compare that Output line with the manufacturer’s requirements.
If you see 20 V, 3.25 A, that means 65 W. Another 65 W adapter can still have the wrong voltage, plug or identification. If the old label is unreadable, use the laptop’s exact model to find the approved part.
The label on the laptop can help identify the model. Our laptop sticker guide explains which labels are worth keeping.
USB-C charging needs a separate check
Consult the laptop manual for charging-capable ports and recommended adapters. A USB-C port used for data or display output may not accept charging. Check the charger’s supported USB Power Delivery profiles and the cable’s power rating.
On a multiport charger, the available power can change when another device is connected. A weak adapter may charge slowly or fail to maintain battery level under load.
Dell’s adapter guidance illustrates these issues, including insufficient wattage, model-specific USB-C support and an unidentified adapter. Follow your own manufacturer’s requirements rather than applying Dell’s details to every laptop.
If the correct charger still does not work
- Check the wall connection and detachable power cable.
- Inspect the plug, cable and laptop port for damage without opening the adapter.
- Check for a model-specific charging limit or adapter warning.
- Ask the manufacturer to confirm a replacement part if the original label is missing.
Stop using a damaged adapter with exposed wires or bent/broken pins. Changing connector tips is not a repair for a damaged charging circuit.
Technical information checked October 14, 2026, using the publisher documentation linked above.