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BMW battery replacement


BMW battery replacement

Your BMW battery gets quite a workout! With all of the electrical systems working in your vehicle there is a requirement for a top quality car battery in good condition at all times! If you have a battery warning, if something just isn't working properly, or if your battery is 4 or 5 years old you might want to consider a new battery for your BMW! Driven SD has the capability to replace your battery and "Register the battery change" in your vehicle just like the BMW dealership does.

New BMW battery

BMW car battery registration

Old Battery

If you put a new battery in your vehicle and  it still needs to be "Registered" (a service function for the charging profile that controls charging capacity) the battery will never be charged properly and you may still continue to have electrical problems! Registering the battery tells the engine computer (DME) that the battery has been replaced and the DME will now control the alternator differently to charge the battery. BMW vehicles charge an aged battery differently than a brand new battery and the registration in the vehicle is essential to a properly maintained BMW battery!

BMW battery coding

In some cases when replacing your car battery the new battery may be of a different capacity. It may be a higher or lower Ah rating than that of the old battery. If that's the case then your BMW has to be coded to let the DME know the car battery is now a different capacity.

Battery capacity

Car battery amp-hour rating

The amp-hour (Ah) rating of a battery is a measure of its electrical storage capacity, and it tells you how much energy the battery can store and release over time. The rating is typically expressed in ampere-hours (Ah) or milliampere-hours (mAh).

The capacity of a battery is determined by the amount of active material in the cells. Active materials are the chemical components inside a battery that store and release electrical energy. An amp-hour is a measure of the amount of active material in a cell.

A battery with a rating of 100 Ah means that it can supply a current of 1 amp for 100 hours, or a current of 10 amps for 10 hours, or any other combination of current and time that results in the same amount of energy being delivered. As the discharge current increases, the capacity of a battery decreases.

When comparing batteries, you should consider the Ah rating along with other factors such as the maximum discharge current, the voltage, and the discharge rate. It is also important to note that a battery can be partially discharged and still have energy left on it, and the rating is a measure of how much energy it can store, not how much energy is left in it.

You should also take into account that the amp-hour rating is based on a specific set of test conditions, such as temperature and discharge rate. These conditions can affect the actual capacity of a battery, so the actual capacity of a battery may be different than the rating.

In summary, the amp-hour rating is a way to measure the energy storage capacity of a battery, and it is important to consider it when comparing different batteries. But other factors such as the discharge rate, voltage and condition of the battery are important to take into account too.

BMW battery types

BMWs use several different types of car batteries, depending on the model and year of the vehicle.

One of the most common types of batteries used in BMWs is the conventional flooded lead-acid battery. This type of battery is also known as a "wet cell" battery, and it is the most common type of car battery. The flooded lead-acid battery has a liquid electrolyte (made of sulfuric acid and water) that is contained in a plastic case. These batteries are relatively inexpensive, and they are widely available. They are also relatively easy to maintain, although they do require occasional topping off of the electrolyte levels.

An AGM reliable battery

Another type of battery that is commonly used in BMWs is the absorbed glass mat (AGM) battery. This type of battery is sealed, meaning that it is maintenance-free and there is no need to check or add water. AGM batteries have a fiberglass mat that absorbs and holds the electrolyte in place. Because of the fiberglass mat, AGM batteries are less prone to leakage, and also tend to be more durable and have a longer service life than traditional lead-acid batteries. They also tend to be more efficient, so they can deliver more power for a longer period of time.

BMW also uses Lithium-ion batteries in some of their cars. This type of batteries are more commonly used in electric and hybrid vehicles. They have a higher energy density, which means they can store more energy in a smaller space. they also tend to be more efficient, and they don't suffer as much from the "memory effect" where a battery "remembers" and can only be recharged to a certain level because it has been repeatedly charged to that level before.

It's important to note that different models, years and even trims of BMWs may use different types of batteries. It's important to use the right type of battery that is compatible with your car, as using an incompatible one may lead to issues and even damage to your vehicle.

BMW vehicle's alternator

Electrical problems and diagnostics

BMWs, like any other vehicles, can experience a wide variety of electrical problems. Some of the most common electrical issues that BMW owners may experience include:

  1. Battery problems: BMWs can have issues with the battery, such as a weak or dying battery, a battery that won't hold a charge, or a battery that drains quickly. These issues can be caused by a variety of factors, including a faulty alternator, a parasitic electrical draw, or simply a battery that has reached the end of its life.

  2. Alternator issues: The alternator is responsible for charging the battery and providing power to the electrical system while the engine is running. A failing alternator can cause a variety of problems, such as a dead battery, dimming headlights, and power windows that won't work.

  3. Starter motor problems: The starter motor is responsible for turning over the engine at startup. A faulty starter motor can cause the engine not to start, or to start with difficulty.

  4. Electrical component failure: Various electrical components such as sensors, actuators, relays, switches, and modules can fail, leading to issues such as warning lights, poor performance, or a lack of certain features (e.g. power windows, seat controls, etc)

  5. Wiring issues: Over time, the wiring in a BMW can become damaged or corroded, which can cause various electrical problems, such as short circuits or open circuits. This can lead to issues such as warning lights, poor performance, or a lack of certain features.

  6. Electronic Control Unit (ECU) failure: There are multiple ECUs in a BMW and they control and monitor many functions in the car. If an ECU fails or develops a problem, it can lead to a wide range of issues, such as warning lights, poor performance, or a lack of certain features.

  7. Complex Electrical systems: BMWs have a variety of advanced electrical systems, like the iDrive system, that can have problems. Such as issues with the navigation system, audio system, or the onboard computer.

It's important to note that this is not an exhaustive list and the electrical problems in a BMW can be complex, and it's best to have a professional diagnose and repair them. In some cases, several issues may be related or interrelated. It's also worth noting that these issues may occur more frequently in older models, but even newer models are not immune to them. Regular maintenance and checkups can help prevent some of the issues and detect others early on, before they turn into bigger problems.

Replacement module coding


When replacing control modules in a BMW there are a few steps that need to be done to ensure proper operation and communication between the new ECU and the rest of the vehicle's systems. These steps may include the following:

  1. Programming the new control module: The new module must be programmed with the specific software and configuration that is appropriate for your vehicle's make, model, and engine type. This can typically be done using ISTA on newer BMW vehicles, or ISTA/P on older BMW cars.

  2. Coding the new module: After programming the new module, it must be coded to the rest of the car's systems. This involves establishing communication between the new module and the other electronic control units (ECUs) in the vehicle, such as the body control module, transmission control module, and others. Coding typically establishes the correct vehicle configuration, security settings, and other data that are specific to the vehicle.

  3. Synchronizing the new control module with the rest of the car's systems: Once the new ECU has been programmed and coded, it must be synchronized with the rest of the car's systems to ensure proper communication and operation. This typically involves the initialization of the sensors and actuators that are connected to the ECU.

  4. Clearing any trouble codes and error messages: After replacing the ECU, it's important to clear any trouble codes or error messages that may have been stored in the car's onboard computer. This is also done using ISTA.

BMW software update

Software updates

BMW software updates refer to updates to the software that controls various systems in a BMW vehicle. These systems include the engine, transmission, suspension, brakes, and various electronic systems such as the onboard computer, navigation system, and entertainment system. Software updates are used to improve the performance, functionality, and security of these systems, as well as to fix bugs and address other issues.

BMW software updates can be grouped into two categories:

  1. Operating System updates

  2. Feature updates

Operating system updates are updates to the core software that runs on the car's computer systems, and it's typically focused on fixing bugs and security vulnerabilities. Feature updates are updates that add new features or improve the functionality of existing features in the car such as new map data, or a new version of the infotainment system.

It's important to note that not all software updates are critical, but some may be important to address security vulnerabilities or fix known issues. It's a good idea to keep your car's software up to date, as it can improve the performance, functionality, and security of your vehicle.


BMW retrofits refer to the process of installing additional equipment or features on a BMW vehicle that were not originally included from the factory. This can include a wide range of equipment, such as navigation systems, backup cameras, parking sensors, custom coding, and many other features.

Retrofits can be done to a BMW vehicle in order to add features that were not available on that particular model or trim when it was originally purchased, or to upgrade an existing feature. For example, a retrofit might be done to add a newer navigation system or to upgrade the infotainment system.

Some retrofits might require the use of specific software, tools and expertise to be done properly and safely.

Retrofits can vary in complexity and cost. Some retrofits may be simple and relatively inexpensive, such as adding a backup camera or parking sensors, while others may be more complex and expensive, such as upgrading to a more advanced navigation system or adding a high-end sound system.

It's important to note that not all retrofits are possible for all BMW models and trims. Some retrofits may also require additional hardware and wiring, or even modifications to the car's body or structure. Additionally, not all retrofits may be compatible with the car's existing software or electrical systems, so it's important to check the compatibility and feasibility of a retrofit before proceeding with one.

Furthermore, not all retrofits may be legal and roadworthy. It's important to check with the local laws and regulations, and to ensure that the retrofitted equipment meets the safety standards and requirements.

Retrofits can be a great way to upgrade your BMW and add features that you want, but it's important to consider the cost, feasibility, compatibility, and legal requirements before proceeding with one. An independent BMW specialist shop or dealership would be the best place to get professional and specific advice on which retrofits are possible and how they should be done.

Electrical diagnostics, repairs, and programming/coding is something that Driven SD is fully capable of taking care of for you at a much more affordable rate than the dealership!

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