1. Introduction
This manual provides essential information for the safe and efficient use of your Kircuit AC Wall Power Charger, designed specifically for the Yoobao 7,800mAh Magic Cube Power Bank YB637. Please read this manual thoroughly before using the product and retain it for future reference.

Figure 1: Kircuit AC Wall Power Charger. This image displays the compact black charger unit with its attached power cable ending in a DC barrel connector.
2. Important Safety Instructions
To ensure safe operation and prevent damage, always follow these basic safety precautions:
- Do not expose the charger to rain or moisture.
- Do not disassemble the charger. Incorrect reassembly may result in electric shock or fire.
- Avoid dropping or subjecting the charger to strong impacts.
- Keep the charger away from excessive heat sources, direct sunlight, or open flames.
- Ensure the input voltage of the power outlet matches the charger's specifications (100V-240V AC).
- Unplug the charger from the power outlet when not in use or during electrical storms.
- Use only with the specified Yoobao 7,800mAh Magic Cube Power Bank YB637.

Figure 2: Built-in Safety Protections. This diagram illustrates the charger's integrated safety features, including short circuit protection, excess voltage protection, overcurrent protection, and over temperature protection.
3. Setup
Setting up your Kircuit AC Wall Power Charger is straightforward:
- Unpack: Carefully remove the charger from its packaging.
- Inspect: Check the charger and cable for any visible damage. Do not use if damaged.
- Connect to Power Bank: Insert the DC barrel connector of the charger cable into the corresponding charging port on your Yoobao 7,800mAh Magic Cube Power Bank YB637. Ensure a firm connection.
- Plug into Wall Outlet: Insert the charger's two-prong plug into a standard AC wall power outlet (100V-240V).

Figure 3: Charger in Use. The image shows the Kircuit charger plugged into a power strip, ready to charge a device. The compact design allows it to fit easily into various power configurations.
4. Operating Instructions
Once connected, the charger will begin supplying power to your Yoobao power bank. The charging status is typically indicated by the power bank itself (refer to your Yoobao power bank's manual for specific charging indicators).
- The charger is designed for continuous use during charging.
- It features built-in protection mechanisms against overcharging, short circuits, and overheating.
- When the power bank is fully charged, you may disconnect the charger from both the power bank and the wall outlet.
5. Maintenance and Care
Proper care will extend the life of your Kircuit charger:
- Cleaning: Disconnect the charger from all power sources before cleaning. Use a soft, dry cloth to wipe the exterior. Do not use liquid cleaners or aerosols.
- Storage: Store the charger in a cool, dry place away from direct sunlight and extreme temperatures.
- Cable Care: Avoid bending or crimping the cable excessively. Do not pull the cable to disconnect the charger; always grasp the plug itself.

Figure 4: Durable Design Elements. This image highlights the robust construction of the charger's cable, featuring thick insulation and abrasion resistance, and the secure, stable connection provided by the well-made plugs.
6. Troubleshooting
If you encounter issues with your charger, refer to the following common problems and solutions:
| Problem | Possible Cause | Solution |
|---|---|---|
| Charger not working / Power bank not charging. |
|
|
| Charger feels warm during operation. | Normal operation. | A slight warmth is normal during charging. If it becomes excessively hot or emits smoke/odor, unplug immediately and discontinue use. |
7. Specifications
| Feature | Detail |
|---|---|
| Brand | Kircuit |
| Model Compatibility | Yoobao 7,800mAh Magic Cube Power Bank YB637 |
| Input Voltage | 100V-240V AC, 50/60Hz, 0.3A |
| Power Source | Corded Electric |
| Main Power Connector Type | 2 Pin (US Standard) |
| Cable Length | Approximately 6.5 ft (2 meters) |
| Special Features | Portable, Travel-friendly, Built-in safety protections (Short Circuit, Excess Voltage, Overcurrent, Over Temperature) |
| Item Weight | 8 ounces (approx. 227 grams) |
Note: Output specifications (voltage and current) are typically printed on the charger label. Please refer to the label on your specific unit for precise output details.
8. Warranty and Support
Kircuit products are designed for reliability and performance. While specific warranty details are not provided in this manual, please refer to your purchase documentation or contact the retailer for information regarding warranty coverage and support.
For technical assistance or inquiries, please contact your point of purchase or visit the Kircuit brand's official support channels if available.