How Long to Charge a Car Battery? Here's How to Know If It's Full
The battery is a crucial component that serves as the power supply to all electrical components of the car. Therefore, regular checks and maintenance are necessary. One of the ways to maintain the battery condition to prevent it from draining is by charging the battery. So how long should a car battery be charged? For more details, please refer to the following review.
How Long Should Car Battery Charging Be Done?
Charging the battery is the best solution for maintaining the battery so that its lifespan meets the maximum usage standard of 2 years. However, if you diligently perform proper battery maintenance, the battery's lifespan can be much longer.
Charging the car battery yourself should not be done carelessly and must be in accordance with the capacity of the battery. To find out the capacity of the battery, you can check the side of the battery packaging.
The time required to charge the battery also depends on the type of charging. The types of charging are divided into slow and fast charging. For more details, please refer to the following review.
1. Slow Battery Charging
The first method of charging the battery can be done using the slow charging method, which involves charging the battery with a small current. This charging aims to avoid overheating conditions in the car.
This charging method can be done at night. As we know, not everyone has the same schedule. Slow battery charging aims for time efficiency.
You must pay attention to safety during charging. You can provide a maximum current of 10% for the battery charging. Here are the things you need to consider when performing slow battery charging.
For example, if your battery capacity is 40 AH with a voltage of 12 volts. Then the calculation method is 40x10%=4AH.
After you calculate the amount of current provided during charging as above, you can use this formula (charging current/battery capacity)+(20% x charging current or battery capacity). For example, (4AH/40AH)+(20%x10) =10+2=12 hours.
In conclusion, for a battery with a capacity of 40AH with a voltage of 12 Volts, you need 12 hours of charging with a charging current of 10%.
Read Also: 6 Ways to Repair a Wet Battery That Cannot Store Charge
2. Fast Battery Charging
As the name suggests, fast battery charging is quicker compared to the previous type of charging. This happens because the current used is 4 times that of slow battery charging, which is 40%. Here’s how to calculate it.
For example, if your battery capacity is 40AH with a voltage of 12 volts, then the calculation is 40%x40=16AH.
The formula for slow or fast battery charging is almost the same, only differing in the charging current used. (40AH/16AH)+(20%x2.5)=2.5+0.5=3 hours.
Very short, isn’t it? This is why many car workshops use this method.
How to Know if the Battery is Fully Charged
To determine if the battery is fully charged or not, you can look for signs that indicate the battery is fully charged as follows.
- Charging stops automatically
- An alarm sound is heard (for chargers that have alarm features)
- The charger indicator light is on
In addition to observing these signs, you can use a multitester to test and determine the battery power. The method is quite simple, place the multitester on both battery terminals, wait until the voltmeter displays the electrical value.
For testing with the engine off, the normal threshold reaches 12-13.6Volts. While for the engine running condition, it reaches 13.7-14.7Volts.
Read Also: Car Battery Performance Dropping? Here’s Why the Car Battery is Not Charging
To ensure safe battery charging, it is best to visit an official workshop or the nearest Daihatsu dealer. This helps avoid the risk of incorrect charging that can cause the battery to drain.
