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Auxiliary Battery Replacement Cost: All That You Need to Know! 

Auxiliary Battery Replacement Cost: All That You Need to Know! 

Auxiliary battery replacement cost ranges from $200 to $300 including both labor and parts costs. This range differs significantly depending on your vehicle's make, model, and year. 

Auto Repairs Are EXPENSIVE

Most vehicles usually come with only one battery. However, certain vehicles use dual batteries or what's called a primary battery and an auxiliary battery.

The primary battery will provide the initial charge to get your vehicle started. On the other hand, the auxiliary battery helps run certain accessories in your car where the alternator cannot keep them going.

This battery is not designed to last forever, and there will be a point in time where you must replace it. This article provides you with all the details you need to know about auxiliary battery replacement costs. We provide you with a step by step guidance on how to replace the auxiliary battery yourself to save on labor costs. 

What does an auxiliary battery do?  

Most vehicles, with only a large battery, usually located under the hood or, in some makes, in the trunk near the spare tire.

There is a common misconception that your vehicle's battery is responsible for charging all electrical components in your car. However, your battery is responsible for just providing the initial charge to get the vehicle going. It's the alternator's job to charge and continue having the electrical components running. 

Some of the higher-end European imports are equipped with multiple batteries. Those vehicles have a primary battery and an auxiliary battery. Having two batteries is to charge some of the accessories that the alternator cannot charge, which requires about 12 volts of power. 

The auxiliary battery is not designed to last forever, and there will be a point of time where you need to replace it or fix it, depending on its condition. 

Luckily, if your auxiliary battery goes bad, your vehicle will not stop running but, you will notice that some of the main electrical components that the alternator cannot charge will not work.

How much does an auxiliary battery cost? 

While the cost to replace the auxiliary battery differs from a vehicle to another, in general, it might cost you between $200 and $300. 

This range includes both parts and labor costs. If you have certain mechanical skill sets, you might even save on labor costs and replace the battery yourself.

Let's take a look below at some of the common auxiliary batteries' costs according to automotive expert’s statistics: 

Vehicle Auxiliary battery replacement cost
2007 Porsche Boxster $344.36
2012 Hyundai Santa Fe $263.66
2010 Acura TL $262.56
2009 Audi A4 $344.36
2009 Ford Expedition $268.06
2007 Saturn Aura $252.66


How long does a Mercedes auxiliary battery last? 

According to recent statistics, your Mercedes auxiliary battery should last between 18 months to three years.

The lifespan of the auxiliary battery depends heavily on your driving style, the frequency of use, and how well you maintain it.

For instance, if you are driving on rough roads frequently, you will notice that your auxiliary battery will not last long because its cells might breakdown as you drive on these rough roads.

Similarly, if you left the auxiliary battery to drain for more than 1/2, you'll notice that it will reduce its performance significantly.

Lastly, if you know that you will be parking your vehicle for a long time, it is recommended to install a battery maintainer to enhance and expand the lifetime of your auxiliary battery.

It is also recommended that you keep an eye on any bad auxiliary battery symptoms by watching how your electrical accessories behave. For example, if you have noticed that your accessories are not operating normally, this indicates that your auxiliary battery might be the culprit. In some scenarios, a faulty auxiliary battery might not even be able to start these electrical accessories. 

Can I drive with an auxiliary battery malfunction? 

Your vehicle's auxiliary battery is not a primary component that will prevent you from driving your car if it's not working properly. 

However, it is not recommended to keep driving your car with a bad or malfunctioning auxiliary battery. This is because it might introduce additional problems to the electrical components that it's supposed to charge.

Did you know that some people don't even fix their auxiliary batteries? Yes, it will not cause any immediate danger or reduce your handling of the vehicle. You will not even notice any difference between your driving and your vehicle's behavior even after a malfunctioning auxiliary battery.

While that's true, you should not continue driving your vehicle after 100 kilometers if your exhilarate battery goes bad and if you would like to keep it working properly. You should get it inspected and repaired by a professional mechanic immediately. 

How do you change an auxiliary battery? 

  • Check if you can replace it yourself 

Before proceeding with replacing your auxiliary battery, it is documented that you check whether you can replace it on your own or not. While the process itself should not be complicated, it is necessary to know that you have the required level of mechanical skill sets.

To do so, you can visit online tutorials and see how the process looks to you. In general, most people should replace their own exhilarate battery if they followed certain correct instructions.

The other thing to check for is whether it's worth replacing your auxiliary battery or not. In some situations, Mercedes might replace your auxiliary battery without charging you. Check with your insurance company and reach out to a dealership. Sometimes replacing the auxiliary battery can be a great area when it comes to warranties. First, your best option would be to have a conversation with your dealership and check whether they are willing to replace it for you without charging you or not.  

  • Choose the right replacement for your auxiliary battery 

Once you confirm whether you need to do it yourself or not, it is not the time to determine the right exhilarate battery that matches and complies with your vehicle's make, model, and year.

Usually, any auxiliary battery that is sealed with a 12 Volt should be good to go. However, it's recommended that you review your vehicle owner's manual and confirm the battery you need to install. 

  • Locate your auxiliary battery 

Once you determine the type of the new battery, it is time to get your vehicle ready and remove the old auxiliary battery.

This battery is usually located behind the driver's dashboard site. However, this location might differ depending on your vehicle's make, model, and year. Thus, refer to your vehicle's manual and detect the auxiliary battery located exactly. 

  • Remove the old auxiliary battery 

To remove your old auxiliary battery, you need to use a trim removal tool to take out the battery without damaging it safely.

First, remove all the Phillips screws on the bottom of your dash panel to detach the battery.

On the auxiliary battery covering, you will need to remove bolts using a ratchet and a socket. Then, you need to unbolt the bracket that is carrying the auxiliary battery. Once you do that, it is time now to disconnect the negative and positive leads from your battery to make sure there is no electrical charge going through the battery and prevent yourself from the risks of getting shocked.

Check for any other bolts before removing your battery from the bracket. Ensure that you support the battery so it doesn't fall inside your vehicle's dashboard.

  • Install the new auxiliary battery 

Follow the exact opposite procedure that you did to remove your vehicle's exhilarate button. Ensure that you're installing the battery in the right position and 1st tighten the bolts holding the bracket. Then, reconnect your vehicle's leads.

After that, tighten the bolts on the lower portion of your battery's brackets. Finally, attach your battery to the lower portion of your dashboard. 

  • Test your new battery 

Once your new auxiliary battery is in place, is the time now to turn on the ignition switch and make sure that you no longer see the error of “battery production convenience functions temporarily unavailable.” Once this error is cleared out, you should be good to go.  

Symptoms of or a bad auxiliary battery malfunction 

When your vehicle's auxiliary battery dies, you will be able to continue driving your car, and you will not notice directly that it has any problem.

However, if you took a closer look at your vehicle's dashboard, you would see an error indicating an auxiliary battery malfunction. In some vehicles, you might even see a battery symbol on the dashboard.


On other newer vehicles, you might even see exact errors indicating that your auxiliary battery is having trouble, including:

  • The battery symbol on the dashboard
  • Stop vehicle shift 2P leave engine running
  • Stop vehicle leave engine running
  • Auxiliary battery malfunction 

Can Mercedes's auxiliary battery be charged? 

The nice thing about auxiliary batteries is that they are rechargeable. You can use a 12 Volt 2.28 H battery.

In general, if your auxiliary battery runs out of charge or if it's charged drops significantly, the alternator will try to charge it.

You can also try and take out the auxiliary battery and charge it externally. Then, you can install it once it's fully charged. 

However, if it continues to drop the charge, the alternator will not charge it, and you will end up with a malfunction.

If you've noticed that your vehicle's auxiliary battery is not holding the charge, then it has a major problem, and you should get it replaced. Otherwise, you might overstress the alternator, which costs too much more money than replacing the auxiliary battery. 

Is it worth fixing my auxiliary battery? 

While fixing the auxiliary battery itself is not considered a measured repair, sometimes it might not be worth fixing it.

Before making a final decision about whether you should fix your auxiliary battery or not, you need to evaluate your vehicle's overall condition. If you have noticed that other major problems are associated with the engine or the transmission, it might not be worth spending this money to fix the auxiliary battery.

Another thing you should investigate is your vehicle's mileage. If you've noticed that your vehicle is around more than 100,000 miles, it is expected that this vehicle will face major repairs. Therefore, it might not be worth fixing a small repair associated with the auxiliary battery, and instead, you should consider shopping for a better vehicle. The used market has a lot of decent vehicles that you can get for a good price. 

Also, if you realize that through fear, costs are getting closer to 75% or more from your vehicle's value, it is not worth spending a penny on this vehicle, and you should sell it instead and use the money as a down payment towards your better vehicle. 

The bottom line 

Auxiliary batteries, or what’s known as secondary batteries, are responsible for charging certain accessories in some vehicles that the alternator cannot charge.

These batteries are not designed to last forever, and you will have to deal with the point where you need to replace them.

To replace an auxiliary battery, you need to spend between $200 and $300, depending on your vehicle's type and condition.

If you've noticed that your vehicle has major problems and it's not worth spending a penny fixing an auxiliary battery, we advise you to get in touch with Cash Cars Buyer who will accept buying your vehicle despite its type or condition.

Whether your car has major issues with the auxiliary battery or even the alternator, we guarantee to buy it.

We provide you with the top dollars you can get around your area along with free towing no matter where you live around the United States. 

To learn more about our process, you can give us a call at 866-924-4608 or visit our home page click on the free instant online offer