How many amps does it take to start a car?

You are in pursuit of buying a new car battery, but you’re not quite sure of how many amps does it take to start a car? First of all, when you think of amps what you are actually want to ask is how many CCA or Cold Cranking Amps, that is what will give your starter a juice to start your car engine. There are many factors involving in starting a car engine, and proper ways to do that.

To start a car engine in most cars 400 amps or CCA is probably more than enough. That will include small and midsize vehicles. If you consider vehicles such as SUVs, trucks and all larger ones out there,  you will probably need more amp, for example 1000 amps, but that depends on how big the engine is, and how much its weight is.

If you’re consider to buy a new car battery based on a CCA, wait until you read this. Let me save your money for you by letting you know that you can recondition your old car battery by yourself. I did it so many times which qualify me as an expert in this field. Be my guest and read my experience on how I was able to recondition so many batteries so far.

Is 300 amps enough to start a car?

Think of that like this, the smaller the car engine is the smaller battery it needs to start. And also opposite, the bigger the car engine is the bigger battery it needs because it’s more hunger for energy.

So to speak, 300 amps will probably be enough for smaller vehicles, like compact cars, economical cars, city cars etc.

Smaller batteries are more cheaper than larger ones, so it will be more economically and you will end up with savings into your pockets. Depending on the car engine it will probably need smaller battery that 300 amps to start the car engine.

For example, nowadays we have cars with the engine of 1.0 liter of cubic centimeters or cc for short. This car engines requires even less battery amps to start.


How many amps to start a diesel?

Diesel engines requires more amps to start, but in apples to apples comparison. For example, if you compare 2.0l diesel and 2.0l petrol, diesel will draw more amps to start the engine, so it will need  car battery with more amps or CCA Cold Cranking Amps.

And also when considering diesel engine we must know that most bigger vehicles such as trucks, tractors, industrial machines, construction machines etc. That kind of vehicles requires bigger batteries to start the engine, so more amps is a must.

In general for smaller diesel engines from 300 amps to 500 amps will be plenty. But larger machines that we mentioned above will need from 1000 amps and more.


Can i put a smaller battery in my car?

Always consult factory specs for your type of vehicle before putting smaller battery into engine compartment.

Putting smaller battery instead of what your car need will result in lack of performance, for example it might won’t to start your engine at all.

But if your car requires 740 amps and you put 680 amps it will work just fine if it is a new car battery.

But, over time when battery starts to lose its capacity it will also affect starting your engine in negative way and it will last less time. So, always read factory specs and put the same car battery rated in CCA or Cold Cranking Amps or bigger.

And if you want to put bigger and larger battery check size of the battery holder inside the engine compartment, it might not fit at all because of its bigger physical size and dimensions.

One more thing, smaller car batteries than it need will wear and tear starter engine. It will negatively affect starter and starter will eventually die because of smaller size car battery rated in CCA.


How many amps does a car starter draw?

Let’s say that we have an car with a 2.0l cc petrol engine. Its starter motor will draws somewhere between 60 and 200 amps when starts the car engine and oil is thin and warm.

That situation will be in warm climate. When you switch the same situation into the colder climate, what you get is oil that is colder and thicker.

Under this condition starter will double in current consumption from battery. In terms in compression ratio diesel engines have it very high, to be precise 22:1, which will result in that diesel cars requires more powerful starter engine from its counterpart petrol engines.

So diesel starter engines draws from 300 amps to 500 amps for the mid sized vehicles from 2.0l to 3.0l cc. And for much more powerful engines such as trucks and construction machines it will go as high as 1000 amps.


How many amps does a car use while running?

This is how it goes. You put key into ignition and start the car, right? So, when you turn on the key what will happen first is that starter engine pull power from car battery to turn on the engine.

Immediately while engine is started alternator starts too. Alternator provide electricity to all devices throughout the running car engine.

How many amps does a car use while running is very different from car to car, because no one car is exactly the same, and also depends on number of devices you are using while running.

For example, you might use radio, which will drawn electricity. Might be warm outside so you decided to turn on the air conditioner into the car, which will also drawn some power from the alternator too.

Or let’s say that you don’t turn on any of this devices, well, you have system built into the car that will drawn electricity whether you wanted or not, such as ECU, water pump, oil pump etc.

And in some point while you driving you might turn left or right and you must turn on the signal light for that, which will result in more amps from alternator.

Unfortunately there in no clear answer on this question. Your better of is to take the amp meter and measure on your own. That way you will be 100% sure on how much amps car use while running.


How many watts does it take to start a car?

Normally a starter engine will use 100 amps to 200 amps of a 12V car battery for 10 to 20 seconds. From this example we can calculate our wanted wattage:


12V x 100amps = 1200W


12V x 200amps = 2400W


This is the range of what you can expect to get, and it is very hard to get definite numbers. After the starter turn on, engine is started with the electronics for the ECU and the spark system.

And in the end we have lights, the daytime lights, and other devices and motor pumps, and how much they are used. After the initial start of the starter, battery will be decrease on its power, so it need to be recharged again.

And that electricity comes from alternator. Battery gets recharged to the top, ready for the next start of the car engine, or I should say entire car system. This is in case you wonder of how many watts need to start the car, you just use formula:


Volts (V) * Amps (amps) = Watts (W)


How many amps to jumpstart a diesel truck?

This might be obvious that answer is that it depends. And it depends on the size of the truck diesel engine and also it depends on that is you battery completely flat or still have some power juice inside.

It’s hard to tell because trucks have such variety of diesel engines, some of them very heavy duty ones. If you want to do a jumpstart on a truck you are better off to find the truck with the same or higher battery capacity, and I am talking about Cold Cranking Amps or CCA.

So, if your truck battery is rated for 1000 CCA you better be to find that same amount of cranking amps.


How many amps should a car battery have?

First, it depends on type of the vehicle you want battery for. You should read factory specs for your vehicle to get that  information.

Some cars requires heavy duty batteries rated in amp hours than others. Also this days we have electric cars which have their own batteries which are massive.

Type of the battery also plays major role in how many amps should a car battery have. Different types of batteries uses different chemistries.

Some of them are standard 12 Volt batteries and some of them are 24 Volt batteries. And some vehicles have more than one battery inside. With all of that, the usual peak electricity current is CCA or Cold Cranking Amps.

Read more if you want to learn how to calculate how many amp hours is in a particular CCA battery.

This is the volume of the current that the battery need to provide for starting the cold engine at 0°F. And answer will be, anywhere from 300 amps to a 1000 amps range, and that is pretty normal.