Here are How Many Amps You Need To Start A Semi Truck!

You’ll have a good day until your semi truck knocks down and refuses to start.

If that’s the first time your semi truck is knocking off, you’ll wonder how many amps it’d take to start.

This article will tell you the number of amps you need to start your semi truck and many other things.

A semi-truck can require as low as 400 amps or as high as 2000 amps to start. One factor is the type of battery you have in your semi-truck, and another is the temperate condition of the truck. During winter, if your truck is stone cold from sitting out for a long time, you’ll need more amps to start it.

How Many Amps Do I Need to Start My Semi Truck?

How Many Amps To Start A Semi Truck

Knowing how many amps you’ll need to jump-start your semi truck is important.

That’s because your semi-truck won’t start without having the right amount of amps to run it.

However, the amount of amps you’ll need for your semi truck depends on your battery type.

While a normal consumer truck might need fewer amps to start up, a commercial one might need higher amps.

Also, that fact applies to small vehicles that don’t need many amps to jump-start but as little as 150 amps.

However, depending on the conditions, your semi-truck might need as much as 1500-2000 amps to start.

Some diesel engines may only need 1000 amps to start if the conditions are favorable for them.

During the winter, when your car is stone cold, it might need you to pass higher amps through it to jump-start.

Also, it’ll require more amps if the cold weather is blocking the heater and other things that should normally warm up the truck.

How Many Amps Does a Semi Truck Battery Have?

A semi-truck battery has a good cold crank capability of about 700 to 1200 amperage.

That amount of CCA would enable a semi-truck to perform at its optimum level during winter periods.

For that reason, semi-trucks are part of a special machinery group named 31

Trucks in that group have batteries that come in handy for heavy machinery and marine equipment.

The batteries have varying sizes ranging from 13×6 to 16×9 inches, with closely-relating numbers of amps and volts.

So, irrespective of the different sizes, they’re closely similar, so you won’t have issues with which one to buy.

Moving on, I’ll tell you that the best way to tell how many amps your semi-truck battery has is to check the battery label.

The battery label will show you the number of cold-cranking amps you’ll need to get the truck rolling again.

However, the number of amps your semi truck needs reflects the truck’s strength.

So while a small truck needs 150 amps to jump-start, a larger truck might need up to 500 amps.

Also, you can use a digital voltmeter to measure your semi truck’s amperage. This table illustrates the amps you need to jump-start and run your truck.

ParticularsSmall TruckLarge Semi Truck
Cold Cranking Amps150 Amps400-800 Amps
Moving Amps400-800 Amps1000-1500 Amps
Volts9-12 Volts12-24 Volts

How Many Volts Do You Need To Start a Semi Truck?

Aside from the number of amps, you’ll also need to know the right amount of volts for the semi-truck to start.

The standard number of volts you’ll need to start your semi truck is 12 volts.

However, that depends largely on the model of the semi-truck you own or you’re driving.

However, the maximum amount of volts your semi truck can use is 24 volts.

That amount is sufficient for even the largest size of batteries that find use in marine equipment and large machinery.

That’s because while an older model would need a small number of volts, say, 12 volts, a newer model will require higher volts.

If the volts are sufficient and you still have problems starting the truck, check the battery and see that it’s enough.

If the battery is fine, the voltage will shoot up to at least 13.5V when you turn on the engine.

However, while a smaller semi truck uses one battery, a large diesel engine runs on an operation of two batteries.

Also, to get your semi truck to start, you’ll need at least nine to ten volts, but the actual amount will depend on some factors.

  • The type of battery that your semi-truck is using is important.
  • The temperature of the semi-truck and its battery are strong factors.
  • The charging method that you use.

However, if you aren’t sure of your battery type, you can go on ahead to use a nine volts battery to charge your truck.

That’s because most of the time, nine volts is enough to start a semi-truck.

How Many Amps To Start a Diesel Truck?

To start a diesel truck, you’ll need about 400 amps for cranking but up to 1000 to 1500 amps to get it moving.

You’ll need that many amps to start the battery of a diesel truck because they’re fairly large.

An inrush current enables the truck to start with less than 400 amps but requires higher amps to move it. 

Getting your truck rolling on the road requires you to pass at least 1000 amps through it.

One good thing about the diesel truck is that temperature and climatic changes don’t affect the battery.

So whether it’s the winter period or summer, you’ll still need the same number of amps to start it.

Also, you wouldn’t need to wait longer than expected for it to start moving when you pass the right volts and amps.

That’s because the diesel truck comes with twin batteries that’d start up the truck quickly when you pass the right number of amps.

Can You Jump Start a Semi-Truck With a Car?

It’s possible to jump-start a semi-truck with a car; This comes in handy when the semi-truck knocks off while in a truck park, or you have to be somewhere quickly.

So, getting a tower to tow the car or calling a professional mechanic to sort it out might be a waste of time.

While planning to jump-start a semi-truck with a car, you must ensure to use a car having the same volts as your truck.

But if you aren’t sure of the number of volts your truck has, you can go on and use a nine-volt car.

However, a nine volts charge might not be sufficient to keep the truck running for a long time. 

Hence, it’d be better to jump-start your semi truck with a car with higher battery volts, say a 12V battery.

That’d be sufficient to keep the truck running for a long time since most trucks come with a standard voltage of 12V.

Here are a few simple steps to jump-start your car truck.

  • Turn on the engine of the small car you want to use.
  • Ensure that the engine of your semi truck is off.
  • Connect the jumper cables to the small car and the semi-truck. Ensure that on the terminals, the positives go with positives while negatives go with negatives.
  • Wait for some minutes, and then turn on the semi-truck engine. It should have sufficient amps to start at this point.

However, if the battery of the semi-truck is dead and that doesn’t work, you might need another truck’s battery to start it. How Do I Know If My Jeep Needs A New Battery?


When your semi truck refuses to start after sitting out for a long time in cold weather, it’s normal to feel bad.

However, rather than wasting time worrying, the first thing you should do is seek help.

You can either use a smaller car to jump-start it or get another truck with similar volts to get it rolling.

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