Have you ever been in the frustrating situation of trying to start your car and realizing that the battery is dead? It can happen to anyone, but fortunately, it’s a problem that can be easily solved with the help of a jump-starter. In this step-by-step guide, we’ll show you how to jump-start a car with a dead battery and also highlight some of the other great features of a jump starter.

Ports and Functional Description

The surface of the YESPER Jump Starter has many features, such as the Indicator, Power Switch, LED Flashlight, In/Out port, and more. Each feature serves a different purpose, such as the Battery Indicator, which displays the remaining battery life. To check the battery power, simply press the power switch.

In the Box

How to Jump-start a Vehicle

Step 1: Connect the smart jumper cable fully into this unit and make sure two indicators on the jumper cable is off

Step 2: Press the power button

Step 3: Start your car engine

Step 4: When the vehicle has been started, remove the jumper cable from the jump starter and vehicle battery.

How to Charge Your Phone, iWatch, Bluetooth Headphones, or Tablet

Press the power switch, the unit can identify your device and charge it automatically. The battery indicators will be lit up when charging.

How to Turn On/Off The LED Flashlight

Long press the power switch for 3 seconds to start the LED light. There are 3 modes of LED light that appear in order (Normal, Strobe, SOS, Off ) if you press slightly.

How to Use YESPER Jump Starter's DC Output 

Many YESPER Jump Starters come with DC Output, featuring 15V/10A or 12V/10A options. Our YESPER Speed 2160 and YESPER Speed 4120 Jump Starters are capable of reaching 150W. To use the DC Output feature, simply follow these steps:
  1. Connect the DC output: Connect the DC output cable to the DC output port of the YESPER Jump Starter and the DC input port of the device being powered, ensuring a secure connection.
  2. Power on the device: Turn on the power of the device being powered and check if it is running normally.


May 10, 2023


Tee Are said:

Purchased a Yesper 4120 from Amazon. Was surprised to find that no charger cable came with it. I plugged in my Android phone charger and it’s been charging at the 3rd level for an hour. How long until it’s fully charged?

mike,hit the seitch and said:

Bought a new Yesper 4120 on Amazon. Plugged in the charging cord, turned on the switch and all 4 blue lights lit up. Lights went off in a minute.
Question: Did the yesper arrive fully charged? Do I have to charge the unit until all 4 blue lights light up again to indicate fully charged? When should I oull the charging cord
Cannot find the answer on the website.

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