How does a Jump Starter Box Work?

Many people doubt that a small jump starter box is powerful enough to start their car, especially when they are told these can boost big gas and diesel motors, like 10 L and more. Today we’ll learn a bit about how these work and why they can get you back on the road in a matter of seconds.

The external anatomy of a jump starter

External Anatomy of a Jump Starter
External Anatomy of a Jump Starter

Power On/Off – Boost Mode: This button turns on the jump starter and in some cases when pushed for a few seconds, the boost mode is activated.

Jump Starter Connector: This is used to plug the alligator terminals to the power source of the jump starter.

Charge Level Indicator: These LEDs will show the amount of charge your jump starter box has. 4 bars indicate 100% charge and 1 bar is 25% of charge.

LED Lamp: In case you need to jump your battery at night, this bright LED lamp will help you with the task.

Positive Cable: This red cable has the positive (goig) current to start the battery.

Negative Cable: This black cable has the negative (returning) current to start the battery.

Positive Clamp: The red alligator connector goes to the positive terminal of your battery.

Negative Clamp: The black alligator connector goes to the negative terminal of your battery.

USB Charger: These booster boxes often come equipped with USB ports to charge other small electronics like smartphones, cameras and more. They also work to charge the booster itself.

Current Output Capacity: This rating tells you how many Amps of current the booster will give you. Most commercial vehicles can start with 600 Amps.

The internal anatomy of a Jump Starter

Internal Anatomy of a Jump Starter
Internal Anatomy of a Jump Starter

Battery Cells: This is where the energy of the jump starter is stored once it is charged.

Positive Cable: This cable helps the stored energy to reach the battery of your car.

Negative Cable: This cable closes the circuit so that the energy can flow constantly from the jump starter to the battery.

Diode Bridge: This bridge ensures the current flows only one way and thus your battery and your jump starter are protected against reversal connections.

PCB: The Printed Circuit Board contains all the circuitry and components needed for the operation and control of the jump starter.

What happens when you jump start your car’s battery with these boxes?

When you use a jump starter box to boost your car’s battery, what is really happening is you are connecting your car’s battery to the internal battery this jumper box comes with.

The internal battery of the jump starter, along with all the circuitry inside it, are designed to deliver a huge amount of energy to your car’s battery and thus give your motor that initial boost to get it started.

Once this happens, the alternator will keep the engine running and charge your car’s battery at the same time.

It is important to understand these boosters are not chargers by nature, but only jump starters. Unless your jump starter is also label as a charger by its manufacturer, you should not assume these boxes can charge a battery.