There are a few components of a car that a car owner should have knowledge about. The knowledge about them is important not only for troubleshooting and replacement purposes but also for using those components in combination with other electronic gadgets. There are many important components of a car, and a battery is critical.
The battery plays its part in starting the car engine and powering lights, multimedia systems, and air conditioners. Most car owners may know that their car battery belongs to the 12-volt category, but not many of them are aware of car battery ampere ratings. It is essential to know the parameters before charging your battery. In this article, we will explain what ampere rating is and how to figure it out for your car battery.
How Many Amps Is a Car Battery?
The ampere-hour rating denotes the power and longevity of a battery. It also hints at the hours a battery would last without a recharge. The ampere-hour rating for larger batteries, such as car batteries, is generally 20 hours.
Most car batteries range between 40 and 65 ampere hours. The “mAh” on the battery generally conveys how much amperage the battery outputs in an hour. You can usually find the mAh rating in the car manual or on one of the battery’s sides.
Size and type of vehicle dictate a battery’s amps, but most car batteries are 550 to 1,000 amps. For example, some experts recommend a heavier-duty truck’s battery be over 1,000 amps. Meanwhile, a smaller car may be in the 400-to-600-amp range.
The battery requirements vary depending on the model/brand. Small car batteries work for 40 ampere-hours, while larger ones will easily last for 50. More oversized vehicles, like trucks, use batteries with 75 ampere-hours capacity.
Car experts recommend paying attention to voltage readings, battery size, and Cold Cranking Amps (CCA) before choosing a car battery.
What is CCA?
Cold Cranking Amperes, popularly referred to as CCA, is a rating that defines a battery’s ability to start an engine, especially in cold temperatures. It also refers to the number of amperes a 12-volt battery can deliver for 30 seconds before the voltage drops to 7.2 volts per second.
The higher the CCA, the greater the starting power of the battery. The CCA rating is critical during winter, as it’s easier for you to start the car in warm rather than cold weather.
An ideal CCA rating would range between 150 CCAs to 500 CCAs, depending on the size and capacity of the battery. CCA also provides an accurate estimate of a battery’s life, determining how well it will perform in lower temperatures.
Factors that can Decrease Battery Capacity
Age: Usually, as the battery gets old, its health also decreases, which is why the amp hours decline. This fact is why some old batteries easily drain.
Temperature: Normally, moderately warm temperatures ensure the highest efficiency. Under cold temperatures, the battery capacity slightly decreases, which is why during winter, its power may not be enough to energize the electrical components of your car.
How Do You Measure Car Battery Amps?
If you do not know the total capacity and the current capacity of your car battery, you cannot just charge it for hours randomly. Therefore, you have to know the car battery amps and you can use a battery tester or a digital multimeter to measure it.
If you are using a multimeter, you can measure the volt of the battery. To measure amps, you have to know the ohm rating of the battery. Using Ohm’s law, you can find amps by dividing the measured volt by the ohm rating of the car battery.
However, by doing some back-calculation of a standard car battery, you can understand how much the current charge of the car battery is. You need to measure the voltage by turning your multimeter to DC and putting the red lead to the positive battery terminal and the black lead to the negative terminal.
| Multimeter Reading (Volt) | Percentage of Charge Remaining |
| 12.6 | 100% |
| 12.4 | 75% |
| 12.2 | 50% |
| 12.0 | 25% |
| 11.9 and below | Dead |
When you know the percentage of charge remaining, you can calculate the current car battery amps. If a 1000-amp battery has 50% capacity, then the current car battery amps is 500.
FAQs.
How many amps are in a 12-volt car battery?
Most of us assume the car battery belongs to the 12 volts category, but not all of us are aware of the ampere rating of our vehicle. An average car battery has a capacity of around 48 amp hours; when fully charged, it delivers 1 amp for 48 hours, two amps for 24 hours, and so on.
Should I charge my car battery at 2 amps or 10 amps?
If you want a faster battery charge rate, go with the 10 amps. Low charging current at 2 amps can be unreliable, but it won’t hurt if you have two chargers.
How many amps is needed to jump-start a car?
That being said, a small to medium-sized car would take around 200-400 amps to start the engine. Similarly, a large-sized automobile would probably need close to 1000 amps. However, a large truck would require about 1500-2000 amps to start.
How many amps is a 12V cigarette lighter?
A car cigarette lighter has a nominal voltage rating of 12 volts but is limited to 10.2 volts with a maximum current of 10 amps. It can efficiently function as an outlet in cars and is used to provide power to a wide range of devices, such as radios, mobile phones, and laptops.
How many amps does a 12 volt car charger put out?
A 12 volt charger can be had from a low milliamp output (100, 200, 500 milliamps), up to 90 amps, that will plug into a 115 volt wall outlet (chargers above about 65 amps usually require a 20 amp circuit, so check).