How Long Does It Take to Charge a BMW Battery

Charging the battery of your BMW is an important aspect of vehicle maintenance and can significantly impact the performance and lifespan of your vehicle. Knowing how long it takes to charge a BMW battery can help you properly plan and manage the charging process and optimize the charging process’s efficiency and cost-effectiveness.

In this article, we will explore the various factors that can impact the charging time of a BMW battery and provide tips and guidance for accurately calculating the charging time for your BMW vehicle.

I. What is Draining Your BMW Battery?

Several factors may be responsible for draining your BMW battery. The ability to troubleshoot correctly will depend on your understanding of these probable causes, which will help you accurately identify and tackle these power leakages. These causes can include:

  1. Lights require a significant amount of power to operate, and if they are left on for an extended period while the car is not in use, the battery will not have enough time to recharge between uses.
  2. External devices, such as a GPS or a phone charger, connected to the battery can also drain the battery if they are left on while the car is not in use.
  3. OBD (On-Board Diagnostics) scanners are useful for identifying issues with a vehicle, and they can also drain the battery if left connected for an extended period.
  4. BMW Intelligent Battery Sensor is designed to help prevent battery drain, but it can sometimes cause the battery to drain if it is not functioning properly.
  5. If the climate control panel is left on while the car is not in use, it can drain the battery as it requires a constant power source.
  6. If the alternator is not functioning properly, it may not be able to recharge the battery as quickly as it should, leading to battery drain.
  7. A faulty battery can also cause battery drain as it may not hold a charge as well as it should, leading to a quicker drain on the battery.
  8. As a battery gets older, it may not hold a charge as well as it used to and can lead to battery drain since the battery may not have enough power to run the vehicle’s systems.
  9. Corrosion on the battery head can disrupt the flow of electricity from the battery to the vehicle’s systems, causing the battery to drain more quickly.
  10. Cold weather can cause the battery’s chemical reactions to slow down, leading to a slower charge and a quicker drain on the battery.

II. Stats You Need to Know Before Charging Time Calculation for Your BMW

Statistics are essential tools for predicting and planning the optimal use of your vehicle, including parts such as your batteries. You need to consider some important ones before calculating your BMW’s charging time.

Battery capacity/Car model: The battery’s capacity is the amount of electrical charge it can hold, and it is measured in Amp-hours (Ah). Knowing the battery’s capacity to calculate the charging time accurately is important. Also, note that different models may have different battery capacities and electrical systems.

Range: The range of the car, or the distance it can travel on a single charge, can also impact the charging time. A car with a longer range will likely require more time to charge.

Starting charge level of battery power: The starting charge level of the battery is the amount of electrical charge it has when the charging process begins. A battery with a lower starting charge level will likely require more time to charge.

Target charge level: The target charge level is the desired amount of electrical charge the battery should have when the charging process is complete. A battery that needs to be charged to a higher target level will likely require more time to charge.

Charging electric current: The electric current used to charge the battery can also impact the charging time. AC (alternating current) charging tends to be slower than DC (direct current).

Charging power in kW: The charging power, measured in kilowatts (kW), is the rate at which the battery is charged. A higher charging power of a home charging station will result in a faster charging time.

III. How do I Calculate the Charging Time for a BMW Battery?

Calculating the charging time of your BMW battery may be necessary when planning your driving and charging schedule or estimating electricity costs. To calculate the charging time for a BMW battery, you will need to gather the following information:

  1. The capacity of the battery in Amp-hours (Ah): You can usually find it in the owner’s manual or by contacting the manufacturer.
  2. The starting charge level of the battery in Amp-hours (Ah): It is easy to determine it using a battery tester or multimeter.
  3. The target charge level in Amp-hours (Ah): When the charging process is complete, this should be the desired amount of electrical charge the battery should have.
  4. The charging electric current, either AC or DC: AC charging tends to be slower than DC charging.
  5. The charging power in kilowatts (kW). This is the rate at which the battery is charged.

With this information, you can use the following formula to calculate the charging time:

Charging time = (target charge level – starting charge level) / (charging power x charging efficiency)

For example, suppose the battery capacity is 100 Ah with a starting charge level of 50 Ah, a target charge level is 90 Ah, the charging electric current is AC, and the charging power is 2 kW. The charging time would be calculated as follows:

Charging time = (90 Ah – 50 Ah) / (2 kW x 0.8) = 20 Ah / 1.6 kW = 12.5 hours.

It is worth noting that the charging efficiency is usually around 80% for AC charging and 95% for DC charging. It is important to consider the charging efficiency when calculating the charging time to get a more accurate estimate.

IV. How Long Does It Take to Charge a Dead BMW Battery?

A completely dead battery can generally be recharged, although it may take longer and require a higher or more efficient charging power. However, it is essential to note that a completely dead battery may not be able to hold a charge due to damage or other issues. In this case, you may need to replace the battery.

The time it takes to charge a dead BMW battery will depend on several factors, including the battery capacity, the starting charge level, the target charge level, the charging electric current, and the charging power of the level 2 ev charger. On average, it can take anywhere from 8 to 16 hours to fully charge a dead BMW battery using a standard car charger. However, this time can vary significantly depending on the specific battery and charging setup.

For instance, if the battery has a capacity of 50 Ah, a starting charge level of 0%, and a target charge level of 100% and is being charged at a rate of 3 kW using AC, the charging time would be calculated as follows:

Charging time = (100 – 0) / (3 / 50) = 100 / (3 / 50) = 100 / 0.06 = 1666.67 hours

This means it would take approximately 1666.67 hours, or 69.4 days, to fully charge the battery from a starting charge level of 0% to a target charge level of 100%.

It is important to note that charging a dead battery may take longer than normal due to the increased strain on the electrical system and the battery’s decreased capacity. It may also be necessary to use a higher charging power or a more efficient charging method to fully charge the battery in a reasonable amount of time. While you can generally recharge a dead battery, it is crucial to properly diagnose and address any issues causing the battery to drain or not hold a charge.

V. How Long Does It Take to Charge for a Certain Distance?

To calculate the charging time for a certain distance, you will need first to determine the range of your vehicle. You can typically find this in the owner’s manual or by contacting the manufacturer.

Next, you will need to determine the target charge level required to travel the desired distance. For example, if the range of your vehicle is 200 miles and you want to travel 100 miles, you will need to charge the battery to 50% of its capacity. Then, you can use the following formula to calculate the charging time:

Charging time = (target charge level – starting charge level) / (charging power in kW / battery capacity in Ah)

For example, if your BMW has a battery capacity of 50 Ah, a starting charge level of 20%, a target charge level of 50%, and is being charged at a rate of 3 kW using AC, the charging time would be calculated as follows:

Charging time = (50 – 20) / (3 / 50) = 30 / (3 / 50) = 30 / 0.06 = 500 hours

This means it would take approximately 500 hours, or 20.8 days, to charge the battery from a starting charge level of 20% to a target charge level of 50% to travel 100 miles.

It is important to note that this is just a rough estimate, and the actual charging time may vary depending on the specific battery and charging setup. It is always best to consult the owner’s manual or manufacturer for more accurate charging time calculations.

VI. Charging Your BMW Battery: Things to Remember

When charging your BMW battery, it is important to remember the following:

  1. Use the correct charger: Make sure to use a charger compatible with your BMW’s battery and electrical system. Using the wrong charger can damage the battery or electrical system.
  2. Follow the manufacturer’s instructions: Carefully read and follow the manufacturer’s instructions for charging the battery. This will ensure that the battery is charged safely and efficiently.
  3. Charge at the correct rate: Charging the battery at a rate that is too high or too low can damage the battery or shorten its lifespan. It is vital to use the correct charging power and electric current as recommended by the manufacturer.
  4. Monitor the charging process: Regularly check on the charging process and ensure that the battery is charging correctly. If you notice any issues, stop the charging process and consult the owner’s manual or manufacturer for further guidance.
  5. Use caution: Always handle the battery and charger with caution to avoid injury or damage.

Conclusion

Charging the battery of your BMW is an important aspect of vehicle maintenance that can significantly impact your vehicle’s performance and lifespan. By understanding the various factors that can affect the charging time of a BMW battery and correctly calculating the charging time for your specific vehicle, you can optimize the efficiency and cost-effectiveness of the charging process and adequately care for and maintain your battery. Following these tips can help ensure your BMW battery is charged safely and efficiently, ultimately leading to a longer-lasting and more efficient vehicle.

Author: Brandon Park