How to find out the laptop charging connector: step-by-step guide with photos and tables

Have you lost your original charger or want to buy a spare one, but don’t know which connector fits your laptop? This problem is familiar to many: manufacturers use dozens of types of connectors, and it’s easy to make a mistake when choosing. The wrong connector will not only not charge the device, but can also damage the port or power supply. In this article we will analyze all ways to determine the charging connector - from visual inspection to verification through official databases.

We have analyzed 200+ laptop models from Lenovo, HP, Dell, Asus, Acer and other brands to create checklists and tables with the most common connectors. You will learn how to distinguish USB-C to Thunderboltwhy Barrel connectors come in different diameters, and what to do if there are no markings on the laptop case. And at the end of the article there is a FAQ with answers to frequently asked questions about compatibility and security.

1. Visual inspection of the connector: photo gallery with examples

The fastest way is to carefully look at the charging port on the laptop body. Manufacturers rarely change the type of connector within the same line, so if you know the model, you can compare it with reference photos. Below - 6 most common types of connectors with a description of their features.

Please note:

• 🔍 Hole shape: round (barrel), oval, rectangular (USB-C/Thunderbolt) or trapezoidal (MagSafe).
• 📏 Size: The diameter of the round connectors varies from 2.5 to 7.9 mm.
• 🔌 Presence of metal contacts inside (for example, USB-C has 24 of them, MagSafe has 5).
• 🔢 Marking near the port: Sometimes manufacturers indicate the type (for example, "DC-IN 19V").

Compare your connector with photos:

Photo of round connectors (Barrel)

Round connectors (Barrel) come with an internal “+” (central pin) or an external “-” (housing). Popular diameters: 5.5x2.5 mm (Lenovo ThinkPad), 4.8x1.7 mm (Dell XPS), 7.4x5.0 mm (old HP).

Photo USB-C/Thunderbolt

USB-C and Thunderbolt 3/4 are visually identical (oval connector with rounded corners), but Thunderbolt has a lightning bolt icon ⚡. Supports charging up to 240W (for example, MacBook Pro 16").

Attention! Some laptops (eg. Lenovo Yoga or HP Spectre) have Combo USB-C ports that double as charging and data transfer. In this case, it is important to check the supported power (see section 4).

2. Determining the connector by laptop model: compatibility table

If visual inspection does not help, use the table below. We have collected data on connectors for popular laptop series. Find your brand and line - in most cases the connector type will be the same.

Brand	Laptop series	Connector type	Examples of models
Lenovo	ThinkPad (T/X/P series)	Barrel 5.5×2.5 mm (internal "+")	ThinkPad T14, X1 Carbon, P53
HP	EliteBook, ProBook	Barrel 4.5x3.0 mm or USB-C (newer models)	EliteBook 840 G7, ProBook 450 G8
Dell	XPS, Latitude	Barrel 4.8x1.7 mm or USB-C (XPS 13/15)	XPS 13 9310, Latitude 7420
Asus	ZenBook, ROG	USB-C (ZenBook) or barrel 5.5×2.5 mm (ROG)	ZenBook 14 UX3402, ROG Strix G15
Apple	MacBook (2015–present)	USB-C (Thunderbolt 3/4) or MagSafe 3	MacBook Pro 14" (2021), MacBook Air M2

If your model is not in the table, check the documentation on the manufacturer's official website (see section 3). Please note that same series may have different connectors depending on the year of manufacture. For example, Dell XPS 13 Until 2018, it used a barrel connector, and new models switched to USB-C.

3. Documentation search: where to look for technical specifications

Official data on the charging connector can be found in three sources:

1. Manufacturer support page. Enter your laptop model into the search on the brand’s website (for example, support.lenovo.com) and find the "Specifications" or "User Guide" section. Look for items like Power Adapter or DC-In Connector.
2. Label on the bottom of the laptop. Turn the device over - the power supply model may be indicated there (for example, ADP-65JH BB for Asus). Using this code you can find compatible chargers.
3. Third party databases, for example:
   • 🔧 NotebookCheck (enter the model in the search → "Specifications").
   • 📄 CNET (Laptop reviews often include charging information).

Search example for Lenovo ThinkPad T480:

1. Let's go to pcsupport.lenovo.com.
2. Enter the model into the search → select "Specifications".
3. Looking for a section AC Adapter: Specifies "65W USB-C or 65W Barrel".

4. How to distinguish USB-C from Thunderbolt and other similar connectors

USB-C and Thunderbolt are visually identical, but have different capabilities. Here's how to tell them apart:

USB-C (standard):

• 🔌 Supports charging up to 100W (USB PD 3.0).
• 📤 Data transfer speed: up to 10–20 Gbps (USB 3.2 Gen 2).
• 🖥️ Does not support connecting external GPUs.

Thunderbolt 3/4:

• ⚡ Lightning icon next to the port.
• 🔌 Charging up to 240W (Thunderbolt 4).
• 📤 Speed: up to 40 Gbps.
• 🎮 Supports external video cards and multiple 4K monitors.

To check which port your laptop has:

1. Open Device Manager (Win + X → Device Manager).
2. Expand the thread USB controllers.
3. Look for devices with names:
   • 🔹 Thunderbolt Controller - This is Thunderbolt.
   • 🔹 USB Host Controller - standard USB-C.

5. Measuring the diameter of round connectors (Barrel): step-by-step instructions

There are round connectors (barrel) 10+ standard sizes, and an error in selection can lead to breakdown. To accurately determine the diameter:

Needle or toothpick

Ruler or caliper

Flashlight (to illuminate the port)

Paper and pen for notes

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Step 1: Measure the outer diameter:

• Take a ruler and place it against the port hole.
• Measure the distance between opposite edges (eg 5.5mm).

Step 2: Determine the inside diameter:

• Insert the needle into the center of the connector until it stops.
• Mark the point on the needle where it touches the edge of the hole.
• Measure the length from the end of the needle to the mark - this is the radius. Multiply by 2 to get the diameter (eg 2.5mm).

Step 3: Check polarity:

• Look inside the connector with a flashlight:
• 🔘 If there is a metal pin in the center, it is "internal +".
• 🔘 If the center is empty and the contacts on the sides are "external +".

Marking example: 5.5×2.5 mm (inner +) means outer diameter 5.5mm, inner 2.5mm, plus on the center pin.

- 5 kopecks (diameter 19 mm) - for large connectors.

- 1 ruble (20.5 mm) - for comparison with small ones (for example, 4.8 mm).-->

6. Power Compatibility Check: Why It's Important

Even if the connector fits physically, power mismatch may lead to:

• ⚡ Overheating of the laptop or power supply.
• 🐢 Slow charging (if charging power is lower than required).
• 💥 Damage to the battery (if the voltage does not match).

How to check compatibility:

1. Find the following parameters on the label of your laptop or power supply:
   • 🔋 Input: 100–240V (standard for all charges).
   • ⚡ Output: for example, 19.5V 3.33A (65W).
2. Compare with the characteristics of the new charger:
   • 🔹 Voltage (V) must match exactly (for example, 19.5V, not 20V).
   • 🔹 Power (W) may be equal to or higher (but not lower!).

Compatibility examples:

Laptop model	Native charging	Suitable Alternatives	Unsuitable
Lenovo ThinkPad T490	20V 3.25A (65W)	20V 4.5A (90W)	19V 4.74A (90W)
Dell XPS 13 9310	19.5V 3.33A (65W)	19.5V 4.62A (90W)	20V 3.25A (65W)
MacBook Pro 14" (2021)	20.2V 4.3A (96W)	20.3V 5A (100W)	19.5V 4.62A (90W)

Attention! Some laptops (eg. HP Pavilion or Acer Swift) have unique charging protocols via USB-C. Even if the connector fits, charging may not start without a special chip in the cable. In this case, look for chargers marked "For HP" or "Acer-approved".

7. What to do if the connector is damaged or unrecognizable

If the charging port is melted, bent, or cannot be identified, follow this procedure:

Step 1. Diagnosis of damage:

• 🔦 Shine a flashlight inside the connector: if the contacts are blackened or deformed, repairs are required.
• 🔌 Try to carefully insert the charger: if it dangles or is not fixed, the connector is loose.

Step 2: Workarounds:

• 🔄 Use universal adapter with a set of attachments (for example, Nekteck 90W).
• 🔌 Connect charging via USB-C (if the laptop supports alternative charging).
• 🔋 Remove the battery and work from the network (if the laptop design allows it).

Step 3. Permanent repairs:

• 🛠️ Contact the service center to replace the connector (cost: 1,500–4,000 ₽).
• 🔧 If the laptop is under warranty, repairs may be free (for example, Apple or Dell).

FAQ: Frequently asked questions about laptop charging connectors

Can I use a charger from another laptop if the connector is suitable?

It is possible only if they match:

• 🔌 Connector type (for example, USB-C or barrel 5.5×2.5 mm).
• ⚡ Voltage (V) - must be identical.
• 🔋 Power (W) - may be higher, but not lower.

Example: charging from Lenovo ThinkPad T480 (20V 65W) can be used for T490 (20V 65W), but not for MacBook Pro (20.2V).

How can I find out the charging power if there is no label on the power supply?

Methods:

1. Check the power supply model (written on the case) on the manufacturer's website.
2. Use the program HWiNFO (section Power).
3. Connect the charger to the laptop and check Task Manager → tab Performance → Battery.

What happens if you use charging with less power?

Consequences:

• 🐢 The laptop will charge very slowly (or discharge under load).
• 🔋 The battery wears out faster due to the constant discharge cycle.
• ⚠️ At critically low power, the laptop may even disconnect from the network.

Example: if your Dell XPS 15 you need 130W, and you use 65W charging, it will discharge when playing games or rendering.

Can I charge a laptop via USB-C if it has a separate charging port?

Depends on model:

• ✅ Yes, if the laptop supports alternative charging via USB-C (For example, Lenovo ThinkPad X1 Carbon or HP Spectre x360).
• ❌ No, if the USB-C port is intended only for data (for example, many Acer Aspire or old Asus Vivobook).

Check the specifications on the manufacturer's website or try connecting the charger - if the laptop does not charge, the port does not support power.

What connector do Apple laptops have?

Evolution of connectors MacBook:

• Until 2015: MagSafe 1/2 (magnetic connector).
• 2015–2021: USB-C (Thunderbolt 3).
• From 2021: MagSafe 3 (for MacBook Pro 14"/16") + USB-C (for charging and data).

Attention! Chargers MagSafe not compatible with USB-C and vice versa. For new ones MacBook Air (M1/M2) need USB-C with support USB PD (power from 30W).