Introduction
The YESPER MONSTER START X1 is a powerful and versatile jump starter designed for a wide range of vehicles, including motorcycles, passenger cars, large trucks, buses, construction machinery, agricultural machinery, and boats. With an ultra-large capacity of 58800mAh and a peak current of 6000A, this device can provide emergency starts for 12V vehicles up to 85 times and 24V vehicles up to 65 times on a single full charge. It features automatic 12V/24V voltage detection and multiple safety protections to ensure reliable and safe operation in various conditions.

Image: The YESPER MONSTER START X1 Jump Starter, a powerful and portable device for emergency vehicle starts.
Safety Information
The YESPER MONSTER START X1 is equipped with 10 comprehensive safety protection functions to ensure user safety and prevent damage to the device and vehicle. These include:
- Short Circuit Protection
- Overcurrent Protection
- Overcharge Protection
- Overdischarge Protection
- Overheat Protection
- Overvoltage Protection
- Undervoltage Protection
- AI Software Protection
- Reverse Polarity Protection
- Reverse Current Protection
These features prevent sparks and ensure safe operation. Always follow the instructions carefully.

Image: Visual representation of the ten safety protection features integrated into the jump starter.
Package Contents
Please check that all items are present in the package:
- YESPER MONSTER START X1 Jump Starter Unit
- Jump Starter Cables (with clamps)
- Dedicated AC Adapter
- USB-C to USB-A Cable
- Instruction Manual (English)

Image: The complete package contents, including the jump starter, cables, adapter, and manual.
Setup
Before first use, fully charge the YESPER MONSTER START X1 jump starter. Refer to the 'Charging the Jump Starter' section for detailed instructions. Ensure the unit is fully charged for optimal performance and safety.
Operating Instructions
Jump Starting a Vehicle
The MONSTER START X1 supports all 12V gasoline and diesel vehicles, and 24V vehicles up to 560hp. The device automatically detects the vehicle's voltage (12V or 24V) and outputs the optimal voltage.
- Check Battery Level: Ensure the jump starter unit has sufficient charge. The indicator lights will show the current charge level.
- Connect Clamps: Attach the red (+) clamp to the vehicle's positive battery terminal and the black (-) clamp to the vehicle's negative battery terminal.
- Start Engine: Once connected, the jump starter will automatically detect the voltage. Start your vehicle's engine.
- Remove Clamps: After the engine starts, remove the clamps from the vehicle battery within 30 seconds.

Image: The jump starter connected to a truck battery, ready for an emergency start.
Video: A demonstration of using the YESPER MONSTER START X1 to jump start both 24V truck and 12V car engines, highlighting the automatic voltage detection and ease of use.
Charging Electronic Devices (Power Bank Function)
The jump starter features two USB-A output ports:
- USB1: 5V/1A
- USB2: 5V/2.4A
These ports allow for rapid charging of various USB electronic devices such as smartphones, cameras, and tablets.

Image: The jump starter acting as a power bank, charging a smartphone and a tablet simultaneously.
LED Light Function
The integrated LED light offers three modes for various situations:
- Illumination Mode: For general lighting during night work or in dark environments.
- Strobe Mode: For signaling or attracting attention.
- SOS Mode: For emergency signaling.
The LED light can provide approximately 453 hours of continuous illumination, making it suitable for outdoor activities like camping, night fishing, and emergency lighting.

Image: A mechanic utilizing the powerful LED light of the jump starter to illuminate an engine bay during night work.
Charging the Jump Starter
The YESPER MONSTER START X1 features a DC 29V/5A fast charging input. Using the dedicated AC adapter, the unit can be fully charged in approximately 1.5 hours.

Image: The jump starter connected to a wall outlet via its dedicated AC adapter for fast charging.
Maintenance
To ensure the longevity and optimal performance of your YESPER MONSTER START X1, follow these maintenance guidelines:
- Storage: Store the unit in a cool, dry place away from direct sunlight and extreme temperatures.
- Charging: For best battery health, charge the unit every 3-6 months, even if not in use.
- Cleaning: Wipe the unit with a soft, dry cloth. Do not use harsh chemicals or abrasive cleaners.
- Operating Temperature: The unit is designed to operate stably in a wide temperature range from -40℃ to 60℃.
Troubleshooting
If you encounter issues with your jump starter, consider the following:
- Unit Not Turning On: Ensure the unit is sufficiently charged. If the battery is completely depleted, it may take a few minutes of charging before it can power on.
- Vehicle Not Starting: Double-check that the jump starter clamps are securely connected to the correct battery terminals (red to positive, black to negative). Ensure the vehicle's battery is not severely damaged.
- Error Indicators: If any error indicators light up, refer to the safety information section or contact customer support.
Specifications
| Feature | Specification |
|---|---|
| Brand | YESPER |
| Model Name | MONSTER START X1 |
| Product Model Number | Monster Start-X1-373 |
| Peak Current | 6000 Amperes |
| Battery Capacity | 58800mAh |
| Battery Type | Lithium Polymer |
| Voltage | 12V / 24V (Auto-sensing) |
| Compatible Vehicle Types | Motorcycles, Passenger Cars, Trucks, Buses, Boats |
| Product Weight | 4.3 Kilograms |
| Package Dimensions | 29.6 x 24.3 x 20.5 cm |
| Charging Input | DC 29V/5A (Fast Charge) |
| USB Output 1 | 5V/1A |
| USB Output 2 | 5V/2.4A |
| Operating Temperature | -40℃ to 60℃ |
Warranty and Support
The YESPER MONSTER START X1 comes with an 18-month product warranty. All YESPER jump starters are PSE certified, ensuring compliance with safety standards. The PSE certificate number for this product is CTL2207063031-PEC.
Should you encounter any issues or have questions during the warranty period, please do not hesitate to contact our customer support. You can find contact information on our official website or through your purchase platform. We are committed to providing prompt assistance and replacement for any non-conforming products within the warranty period.





