What Is Cold Cranking Amps is a question I see a lot. Cold cranking amps is a measurement of a battery’s ability to start an engine in cold weather. But let’s take a closer look.
Cold-cranking amps rating indicates a battery’s ability to start in low temperatures. A battery’s cold cranking amp (CCA) rating is determined by testing the battery. It measures the number of amps a new 12 Volt battery produces at zero degrees Fahrenheit. The test lasts for 30 seconds and the battery must hold a 7.2 Volt charge for that time.
Whether your car will start in sub-zero conditions depends on several factors. These include how many cold cranking amps its battery can produce. If you live somewhere cold, you can save hassle and money by paying attention to your battery’s CCA rating.
Let’s dive into the details of cold-cranking amps. In this post, we will discuss the following:
- the meaning of cold cranking amps,
- how many CCAs are needed to start a car,
- different types of CCA ratings,
- whether to consider CCA ratings when replacing a battery,
- the role of temperature in starting a car,
- factors to consider when buying a battery.
What Are Cold Cranking Amps?
Cold cranking amps (or CCA) is a formal rating system for car batteries and their capacity to start in cold weather.
Regulatory bodies like the German Institute for Standardization (DIN) and SAE International (formerly the Society of Automotive Engineers) conduct standardized tests to determine the CCA rating of batteries.
The SAE J537 American Standard is used widely as a testing framework for evaluating and designating the CCA rating of car batteries.
This CCA test measures how many amps a 12V battery produces for 30 seconds while it holds a voltage of 7.2V. The test is carried out at an ambient temperature of zero degrees Fahrenheit.
Where Does The Term Cold Cranking Amps Originate?
The term cold cranking amps comes from the era of the first generation of automobiles. In the early 1900s, drivers started cars by hand using a device called a hand crank. This was a physically-demanding and often dangerous task.
The need for hand crank technology disappeared in 1915. This was when Cadillac made the first battery-powered starter motors.
‘Cranking amps’ became the term for the electrical power these early starter batteries produced when initiating the internal combustion process.
How Many CCAs Do You Need?
The number of cold cranking amps needed to start a modern vehicle depends on a number of variables. These variables include:
- ambient temperature,
- engine size and type.
The ambient temperature is a critical variable. This is because car engines function by internal combustion. More cold cranking amps are needed for starting cars in colder weather and climates.
Engine Size And Type
The size and type of engine determine which CCA rating you need to start a vehicle.
The number of cold cranking amps required to start a car is proportional to the size of the vehicle’s engine. Engine size (or displacement) is the total volume of the machine’s cylinders (usually indexed in liters or cubic centimeters).
As a broad guideline for petroleum engines, a battery should have 1 CCA per cubic inch of engine displacement.
Diesel engines need higher levels of electrical charge when starting. So cars with diesel engines need double the number of cold cranking amps for each inch of engine size.
So, if 1 liter equates to 61 cubic inches, a 2.4-liter gasoline engine requires about 146 cold cranking amps to start. A battery with a CCA rating of 280 will suffice for this engine size.
In contrast, a 2.4-liter diesel engine needs at least 192 cold cranking amps. So a 280 CCA battery won’t provide enough power to start a car with a diesel motor of this size.
What Is Considered A Good CCA Rating?
As we’ve learned, batteries with higher CCA ratings produce more cold cranking amps. As such, they start car engines in lower temperatures than those with a low CCA rating. Yet a higher CCA rating is not necessarily superior to lower ratings.
As noted above, the optimal CCA rating depends on your climate and your car’s engine type and size.
There are also several alternative cranking amp ratings for specific car battery applications. These ratings use different testing parameters than those for CCA battery tests.
Cranking amps (CA) is a battery rating for cars intended for use in warm climates. This is usually somewhere temperatures don’t drop below zero. This ranking is also called marine cranking amps (MCA). Testing for CA or MCA ratings is conducted at 32F rather than 0F (like the CCA test).
Pulse hot cranking amps (PHCA) is a rating found on batteries in racing car engines. These batteries tolerate extreme temperatures. The PHCA test uses the same temperature as the CCA test but for only 5 seconds instead of half a minute.
The third rating for car battery starting capacity is hot cranking amps (HCA). HCA is the rating for batteries that operate in high-temperature environments. The HCA test is performed at 80F, which is much higher than CCA testing.
Should I Replace My Battery Based On The CCA Value?
Do you need to be concerned about CCA ratings when replacing the battery in your car?
If you live in a temperate climate, don’t obsess over the number of cold cranking amps your car battery generates. In most cases, the OE (original equipment) will provide enough CCA capacity to start the car in winter.
There is no mechanical or financial benefit to batteries with higher CCA ratings in these circumstances.
But people living in icy cold regions should be attentive to the CCA ratings of their car batteries. If your car endures sub-zero conditions, it is wise to become familiar with the CCA rating of your battery.
When replacing your car battery, select one with the same or higher CCA as the original battery. Batteries with CCA ratings a little higher than required will not damage the engine.
What Role Does Temperature Play In Starting A Vehicle?
Temperature is a critical factor when starting a vehicle.
Car engines start more easily in moderate to warm conditions. Cold temperatures dampen the engine ignition process in various ways.
Cold temperatures impede the starting capacity of car batteries. The capacity of the battery is decreased because of an increase in internal resistance in the cold.
Temperature also affects the viscosity of the oil in the engine. Engine oil becomes less viscous as temperatures increase. Conversely, the oil becomes thicker and denser as the temperature drops.
When starting a car in the cold, the battery needs to generate more Amps. These compensate for the reduced voltage and increased engine oil viscosity.
How to Work Out Your Engine’s Cold Cranking Amps
Determining your engine’s cold cranking amps (CCA) is important for two reasons. First, it will help you to select the correct size battery for your car. And second, knowing the CCA will help diagnose the problem if your car fails to start on a cold morning.
Check the Battery Label
The easiest way to find out your engine’s CCA is to check the label on the battery. The label will usually list the CCA as well as the battery’s other specifications.
If the label does not list the CCA, don’t worry. It will usually also list the Amp Hours of the battery. There is no direct correlation between Ah and CCA. But you can still use the Amp Hours of the battery to get a good estimate of the CCA. Multiply the Ah by 7.25 to get the approximate CCA. For instance, a battery with 60 Amp Hours has a CCA rating of around 431 cold-cranking amps.
Here’s a table that gives you a decent idea.
Check Your Owner’s Manual
If you can’t find the label on the battery, another good place to look is your car’s owner’s manual. The manual will usually list the CCA needed for your vehicle.
This is where you’ll find all the car’s technical information. If you cannot find your owner’s manual, you can try looking online for a PDF version of it.
If you still can’t find the CCA, you can try contacting the manufacturer. It should be able to give you the information you need. If the maker cannot help, or no longer exists, online forums and Facebook groups are good places to ask.
Use your engine capacity
As a broad guideline for petroleum engines, a battery should have 1 CCA per cubic inch of engine displacement. So the first thing to do is calculate this figure. We can get this by using the engine capacity, measured in liters.
To convert liters to cubic inches, we multiply by 61.023. So, for example, if your engine capacity is 3 liters, 3 x 61.023 = 183 cubic inches. This would mean you need a battery with a CCA of at least 183.
However, this rule of thumb only works for petrol engines. If you have a diesel engine, you will need a battery with a higher CCA. This will be around double.
Usually, a car needs
- Diesel: 2 to 3 CCA per cubic inch.
- Petrol: 1 to 2 CCA per cubic inch.
This means that a V8 engine with a capacity of 4.6 litres will require 620 to 930 CCA. As you can see, this is a large margin for error and is far from precise. In layman’s terms, it could be miles out. So it’s always best to check your car’s owner’s manual, or the label on the battery itself.
But remember, these crude calculations will only give you a ballpark figure. There are calculators online which can present you with this information. But they are not accurate enough and don’t take into account factors that can alter the answer.
- These include engine specs or external factors which may increase or reduce resistance or friction. So these might include which accessories are running, the condition of the battery, and the starter motor. And we need to know other mechanical specifications including but not necessarily limited to
- The Compression ratio. This is a measurement of how much effort is needed to compress the air.
- We need to know the number of camshafts and particularly the number of camshaft lobes. The camshaft is a component that causes friction.
- How many crankshaft bearings? Also a friction-causing component
- Is the engine under-square or over-square? Affects the launch of the piston movement load.
- The ratio of ring gear teeth to starter pinion teeth.
- Manual or auto transmission. Whether the user has a manual transmission in neutral or is pushing down on the clutch. With old 6-Volt systems or 12-volt batteries on the way out this can make a noticeable difference.
- Is the throttle open or shut?
- Are there pumping losses? With 6-volt systems, the speed difference is quite noticeable.
Gathering this information is time-consuming and difficult. I would err on the side of using the higher estimate and going with that, but that’s just me.
What is Cold Cranking Amps
Now we know that CCA ratings show how many amps a battery provides when starting a car in low temperatures. So we can appreciate that the CCA rating of a battery is of paramount importance in cold climates. This is where you really need that extra electrical power necessary to start a car engine.
And we can see why CCA ratings aren’t important in areas that do not suffer sub-zero temperatures. So we can avoid expenses and inconvenience by having the appropriate CCA for our battery.
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