How Many AMPs is a Car Battery? The Broader Perspective

Understanding your car battery will help you deal with any issues that may arise. Most people only have a basic understanding of how some parts like the battery works. We all have heard the terms Volts and AMPs, but do we really understand what they mean? In this guide, we will better understand the two terms and know how many amps is a car battery.

What Are Ampere Ratings?

AMP rating or Ampere rating is the storage capacity of a battery. Usually, the higher the AMP rating, the larger the battery and vice versa. However, the battery's internal chemistry can also affect the AMPs battery ratting rather than the sizes. Most batteries used in cars usually have an ampere capacity of between 500AMPs and 1000 AMPs.

Again you will find that the AMPs are further divided into two: Crank AMPs/ CA or MCA (Marine Cranking Amps) and cold-cranking amps /CCA. Usually, the CCA rating is lower than the CA rating. The CA is the maximum current that a fully charged 12-volt battery can deliver for 30 seconds, while the voltage and actual battery temperatures are not lowering below 7.2V at 32°F.

When you want to know how many amps is a car battery, you should pay more attention to the CCA rating. The CCA is the maximum quantity of AMPs a car battery with 12 volts can pump out for 30 seconds at zero degrees Fahrenheit. In other words, the CCA is a measurement of how much electrical power a battery can crank out within 30 seconds before it runs out.

A car with higher cold cranking amps has a great starting power. If you are looking to get a good car battery, you will need to understand tha large cars like diesel-powered trucks, SUVs, or pick-ups will have CCA that range between 800 to 1500. The Small car batteries will usually have a CCA rating of around 400.

With this understanding, let's go ahead and look at a car battery's features and specs before learning how many amps is a car battery.

How Many AMPs is a Car Battery?

Typical car batteries usually have a capacity of approximately 48 amp hours, meaning that when they are fully charged, they will provide 1 amp for 48 hours or 2 hours for 24 hours. Generally, a basic charger typically charges at around 2 amps, which requires 24 hours to provide the 48 amps needed to charge a 48 amp hour battery fully.

In simpler terms, most battery chargers dispatch around 2 amps of power to the battery every hour. And at this rate, it will fully charge within 24 hours. The good side is that the typical car battery charging at this low rate will have a longer life span since the battery will reduce overcharge.

If you want to increase the charging rate, there is a wide rand of chargers with different charge rates that vary from 2 amps to 10 amps. Regardless of the battery charger, you will use, ensure you remove the charger when you have a fully charged battery. Also, you should know that fast charging can cause the car battery plates to buckle; thus, it's not recommended.

Before charging a car battery, you should understand how to measure car battery amps. The amazing thing is that you can use a digital multimeter to check the car battery amps or current power. Also, you could use a battery tester to check the amps in the car battery.

The advantage of using a digital multimeter is that the multimeter will show the voltage, which is more consistent across different car batteries. Volts are the measure of voltage, while amps measure current. The voltage should be at least 12.6 volts when fully charged lead-acid batteries.

To count the battery current voltage, you will need to turn the multimeter to DC, position the red lead of the calculator on the positive of your battery terminal, then position the black lead to the negative battery posts. Once you have the voltage, you can calculate tha Amps.

You can calculate the amps of a car battery from the voltage you will need to know the battery's resistance. You can easily calculate using the formula: I = V/R or voltage divided by resistance is equal to current/ Amps.

Car Battery Charger Types

A basic home battery charger uses a rectifier or a transformer to transform the mains 110/220-volt alternating current to 12-volt direct current. This way, the main supply will provide a charging current at a rate confided by the battery's state.

On the other hand, an average car battery has a capacity of 48 Amp-hours, meaning that a fully charged battery can deliver 1 amp for 48 hours. You can charge a car battery with a standard home charge which will have a charge rate of between 3 to 6 amps.

You will also find that some chargers have a Hi-Lo/ high and low switch, allowing you to pick between two charging rates. But, first, let's look at the car's battery features and specs.

Car Battery Features and Specs

1. Chemistry

Most batteries used for cars are reliable and tested. Lead-acid batteries and flooded lead-acid are what most of us know and use. However, there are being replaced by Sealed Lead Acid (SLA) batteries and Absorbent Glass Mat (AGM) batteries.

2. Voltage

Most car batteries, especially lead-acid car batteries, usually have a voltage of 12, but the actual battery voltage is different. When your car's engine is running and the battery is charging, the voltage is usually in the range of 13.5 to 14 volts. The battery's actual voltage will depend on your model and the onboard electronic system being frequently online.

Note that the voltage drops below 10.8 volts per cell, which means that you are working with a discharged battery. However, draining a battery to 10.8 can cause permanent damage to your battery. Also, as the battery nears full discharge, you will notice that the lights gradually dim out.

3. Capacity

The car's battery capacity is provided in Amps Hours/ Ah. Fundamentally the Ah is the unit of measurement used to show the amount of power in a battery. In other words, Ah is the measure of the battery's capacity expressed as to how long it can deliver a current of one amp per hour before it is fully discharged.

Amps Hours will show how many amps can be provided for 20 hours before the battery voltage drops to 10.8 volts. A car battery usually has a nominal capacity of between the rand of 50 Ah to 100 Ah depending on the size of a car. Usually, the large diesel-powered trucks will have higher Amp hours of up to 100 Ah.

If you find that your car battery does not have an amp-hours value on the label, it is impossible to know the actual value. However, you can work with ballpark estimates, and it will also be important to be conservative if you want to put your car under car starting battery through a deep cycle. However, you should avoid doing so if you want an extended battery life span.

4. Battery Reserve Capacity (RC) 

Reserve capacity is often associated with deep cycle batteries used for marine cars. The RC is the number of minutes a fully charged AGM battery can supply a 25A current and maintain the voltage above 10.5.

The Reserve capacity value is needed more for a deep cycle battery mostly used for marine applications. However, the reserve capacity is becoming important for car batteries as well.

5. Hot Cranking Amps (HCA) 

The hot cranking amps/ HCA is the maximum current value that a fully charged battery can provide for 30 seconds without dropping the voltage to below 7.2 v and 80 degrees Fahrenheit.

Nevertheless, you will find other batteries that have provided these values at different temperatures. In addition, the HCA is usually greater than CCA for most AGM batteries, so you should use the CCA to measure the battery strength.

6. Pulse Hot Cranking Amps (PHCA) 

Pulse hot cranking amps/PHCA is the value of the maximum permitted current that a new car battery that is fully charged may deliver for 3 to 5 seconds at 77 to 80 degrees Fahrenheit. You will also find that some car manufacturers provide room for you to use batteries to provide maximum pulse drain current.

Frequently Asked Questions on Car Batteries

1. What is the proper way to charge a car battery?

If you want to charge a car battery, you will first need to know if you will remove the battery or leave it in the engine bay. If you leave it in, the battery terminals need to be disconnected. Before you even start, you will need to stop the engine. Then check thr electrolyte levels of the battery and pay attention to the water levels.

If you use a battery charger with more than 2 amps, it is advisable to remove the cell caps to provide good ventilation. You will then clamp the + lead, which is red, to the positive battery post and the - lead, which is black, to the negative battery post. You can also fit a line fuse cable lead to the battery as an extra precaution. 

When that is done, you will need to plug th charger into the mains and turn it on. If the cells bubble and disgorge gas in the final stages, the car battery is most likely faulty and should be checked by a garage or battery specialist.

2. What are minimum cold-cranking amps?

When purchasing a battery, you should look for one big enough to permit reliable cold starting. Reliable lead-acid batteries should at least have one CCA for every cubic inch of engine displacement.

3. How many amps do you need to charge an electric car?

Modern electric car batteries can draw a max of 16 to 32 amps when charged from a 240 voltage tier charging station. Nevertheless, you can find other stations which will provide more energy for electric vehicles.

                                                                                             Image credit:

Similar Posts