How to Power an Arduino: All Methods Explained for Beginners

Whether you're prototyping with a breadboard or integrating into a permanent system, choosing the right power method ensures stability, safety, and long-term performance.

In this guide, we'll walk through every common way to power an Arduino, from USB cables and batteries to more advanced solutions like ESC BECs and 18650 lithium cells. We’ll also cover voltage limits and tips to avoid damaging your board.

1. Power Arduino via USB Cable (Laptop or Power Bank)

The easiest and most common method is using a USB Type B cable connected to your:

• Laptop or Desktop PC
• USB Wall Adapter (5V output)
• Power Bank

Why use this?

• Great for beginners.
• Also enables code uploads and serial communication.
• Ideal for temporary or prototyping projects.

Tech specs:

• Voltage: 5V regulated via onboard USB.
• Current limit: Depends on your PC or power source, usually 500mA–1A.

Best for: Beginners, testing, uploading code, and portable power banks.

2. Power Arduino with 18650 Lithium Batteries

Using two 18650 3.7V lithium-ion batteries in series gives you around 7.4V, perfect for the Arduino's VIN pin or barrel jack.

See our full tutorial with wiring and real images:
How to Power Arduino with 18650 Batteries

Why this works:

• VIN or barrel jack accepts 7–12V.
• 18650 batteries are rechargeable and high-capacity (e.g. 6800mAh).
• Offers long runtime for mobile or outdoor applications.

🔌 Wiring Overview:

• Battery holder red wire → VIN
• Battery holder black wire → GND

Caution: Never exceed 12V on VIN. A fully charged pair of 18650s gives ~8.4V, which is safe.

Best for: Portable or battery-powered Arduino projects.

3. Power Arduino with an ESC BEC (5V Output)

If you're working with RC components or drones, you can use a BEC (Battery Eliminator Circuit) integrated into an ESC (Electronic Speed Controller) to power your Arduino at a stable 5V.

Check our hands-on article with images:
How to Power Arduino with ESC BEC

Why use BEC?

• Outputs clean, regulated 5V from a LiPo battery.
• Great for projects with motors or drones.

🔌 Wiring Overview:

• Red (5V) → Arduino 5V pin
• Black (GND) → Arduino GND

Note: Connect only the signal and GND if your ESC is also connected to motors to avoid double power input.

Best for: Robotics, drones, RC projects with LiPo batteries.

Other Ways to Power Arduino

Using Barrel Jack with 9V Adapter

• Standard 9V 1A or 2A wall adapter.
• Jack feeds the onboard regulator.
• Safe and stable for permanent or long-term setups.

9V Battery (Not Recommended for Long Use)

• Can be connected via barrel jack or VIN pin.
• Limited capacity and not rechargeable.
• Only good for very short testing.

AA Battery Packs (4x or 6x)

• 4x AA = ~6V (good for 5V pin directly)
• 6x AA = 9V (good for VIN pin or barrel jack)
• Use rechargeable NiMH for better performance.

When to Use 5V vs VIN on Arduino

Choosing between powering your Arduino through the 5V pin or the VIN pin depends on your power source type and regulation needs.

Use VIN When:

• You are using unregulated DC voltage between 7V and 12V (e.g., 2x 18650 batteries, 9V adapter, or 6x AA).
• You want to utilize the onboard voltage regulator to safely step down to 5V.
• Your source voltage may vary slightly (e.g. freshly charged 18650s = 8.4V).

VIN is internally connected to the voltage regulator. So anything you supply here gets regulated down to 5V.

Example: Powering from 7.4V 18650 pack → Use VIN.

Use 5V When:

• Your power supply is already regulated to 5V (e.g., BEC, 5V USB power bank, step-down converter).
• You want to bypass the onboard regulator and directly power the board.

WARNING: Supplying more than 5V to the 5V pin can permanently damage your Arduino!

Example: Powering from ESC BEC (5V output) → Use 5V pin.

Quick decision table

Pro Tips to Power Arduino Safely

• Always check your voltage source before connecting.
• Avoid powering through both USB and VIN at the same time.
• Use capacitors or diodes to suppress spikes if using motors.
• For advanced stability, consider a regulated 5V step-down module.

Summary & Internal Links

Conclusion

There are many ways to power your Arduino, depending on your project's needs. From plugging into your laptop to powering it with a drone’s battery pack, each method has its benefits. Just remember the voltage input rules:

• VIN/Barrel Jack: 7V–12V
• 5V Pin: Regulated 5V ONLY (BEC FOR EXAMPLE)
• USB: Built-in 5V regulated