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Auxillary Battery Replacement Cost Estimate

Worried you might overpay for your Auxillary Battery replacement? Use Jerry's GarageGuard to get fair cost estimate for your Auxillary Battery replacement.
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John Davis
Expert Automotive Writer
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Reviewed by Kathleen Flear, Director of Content
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Edited by Jessica Barrett, Senior Car & Insurance Editor

How much does it cost to replace an auxiliary battery?

You can expect an average total replacement cost of $193 for an auxiliary battery replacement, with $138 for parts and $55 for mechanic labor costs. The exact price will depend on your vehicle.
A certified mechanic generally takes around 30 minutes to complete an auxiliary battery replacement. They will conduct an inspection and let you know if a replacement is necessary. If so, they’ll complete the full replacement. 
Here’s an overview of auxiliary battery replacement costs for different vehicles:
Estimate DateCustomerCarFair Cost EstimateParts CostLabor CostLabor Time
May 26, 2024
Alfa Romeo Giulia
$203
$169
$34
0.3 Hours
May 24, 2024
Mini Cooper
$201
$169
$32
0.3 Hours
May 17, 2024
BMW M5
$203
$169
$34
0.3 Hours
May 15, 2024
Geo Prizm
$203
$169
$34
0.3 Hours
May 15, 2024
Eagle Talon
$204
$169
$36
0.3 Hours
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How did we estimate these prices?

Jerry's experts researched and collected data from 2500+ real repair shops in all 50 states in the US, including everything from the total cost of repair services to the hourly labor cost for mechanic labor in each shop. We combined that data with our expert database of hundreds of real repair jobs, thousands of real cars, millions of real car part prices in order to best estimate the cost of each repair service. Our labor cost estimate is calculated by taking the average hourly labor rate for a certified mechanic in the US, times the number of hours it takes on average to complete a repair. We recommend you compare your local shops with Jerry and contact those shops directly to get final pricing for your vehicle.

What parts do I need for my auxiliary battery replacement?

Unlike other components of your vehicle, the auxiliary battery is a single part. When it breaks, it’s the only component that needs to be replaced. 
Most vehicles don’t have an auxiliary battery. If yours does, you’ll want to maintain good working order to prevent interference with your car's electrical systems.
On average, an auxiliary battery costs between $142 and $174, plus the cost of labor—but the exact price varies based on your vehicle's make and model.
Some brands we recommend include Optima Batteries, ACDelco, and DieHard. You can typically purchase those brands at retail locations like Autozone, O'Reilly Auto Parts, and Advance Auto Parts - or from online retailers like Amazon, Ebay, and Walmart. However, like price, recommended brands may also vary depending on your vehicle's specific year, make, and model.
When it comes to replacing your auxiliary battery, OEM parts are more reliable. Since they’re produced in the same way as genuine parts, they’re more reliable than aftermarket batteries and tend to have a longer lifespan. OEM parts should also come with a warranty that will protect your battery in the event it’s defective or doesn't work properly. That said, some aftermarket batteries may be an option if they’re purchased from a reputable brand.
You can purchase auxiliary batteries online through auto parts shops like NAPA Auto Parts or AutoZone. You can also find them on Amazon. Check your vehicle’s owner's manual for the specifics of your auxiliary battery.

Where can I get my auxiliary battery replaced?

Finding the right place to get your auxiliary battery replaced can be tricky—especially if you don’t have a trusted mechanic to turn to. Luckily, Jerry's
GarageGuard™
tool can help you compare costs for the services you need from over 2,500 reputable repair shops across the country. 
Jerry's GarageGuard™ tool compares fair price estimates from shops using their actual hourly labor rate. GarageGuard™ will also let you know if you need to budget for diagnostic fees and show you reviews from real customers to help you choose the best service.
Check out some of our vetted shops below and download the app to compare car repair quotes in your area.
177 Reviews
54th Street Auto Center
address
415 W 54th St, New York, NY
Auxiliary Battery Replacement Cost
Fair Cost Estimate for This Shop
$319
(Parts - $158, Labor - $161)
Shop Diagnostic Fee
(Included in service charges)
$191
174 Reviews
Yoo's Auto Service & Collision
address
189 W Duncannon Ave, Philadelphia, PA
Auxiliary Battery Replacement Cost
Fair Cost Estimate for This Shop
$243
(Parts - $158, Labor - $85)
Shop Diagnostic Fee
(Included in service charges)
$100
131 Reviews
Thatcher's Tire Pros & Auto Center
address
5810 Tower Ave, Superior, WI
Auxiliary Battery Replacement Cost
Fair Cost Estimate for This Shop
$257
(Parts - $158, Labor - $99)
Shop Diagnostic Fee
(Included in service charges)
$107
118 Reviews
Laurel Heights Automotive
address
9109 E Gregory Blvd #6407, Raytown, MO
Auxiliary Battery Replacement Cost
Fair Cost Estimate for This Shop
$271
(Parts - $158, Labor - $113)
Shop Diagnostic Fee
(Included in service charges)
$50
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How did we vet these shops?

Jerry experts researched 2500+ real repair shops across the US. We talked to real shop customers, and analyzed both real shop pricing data and thousands of real customer reviews from each shop to verify them individually. We do not partner with the shops listed above, and our analysis is always unbiased.

How will a mechanic replace my auxiliary battery?

If your car has a bad auxiliary battery, your mechanic will replace it by following these steps:
  1. Confirm that the auxiliary battery is faulty
  2. Locate the auxiliary battery—In diesel trucks, the secondary battery is usually located under the hood. In luxury vehicles, EVs, and hybrids, the auxiliary battery may be found under the hood, inside the car under a seat, or in the trunk.
  3. Disconnect the negative and positive battery cables before removing any tie-downs securing the battery in place.
  4. Remove the old auxiliary battery
  5. Install the new auxiliary battery by connecting the positive and negative cables and reattaching the tie-downs.

What happens if I don’t replace my auxiliary battery?

If you notice any symptoms of a faulty auxiliary battery, don’t wait to have it inspected. A faulty auxiliary battery can lead to problems with your car’s electrical components and safety features—or they may stop working entirely. These include:
  • Entertainment system
  • GPS
  • Audio system
  • PDC sensors
  • Blind Spot Assist
  • Lane Keeping Assist
In the worst-case scenario, your car could fail to start or stop. If your car is showing signs of an issue with the auxiliary battery, take it to the mechanic immediately.

What is an auxiliary battery?

An auxiliary battery is a secondary or backup power source that you can find in some vehicles. Luxury brands like Mercedes-Benz, Audi, and BMW usually have an aux battery.
Its purpose is to back up the primary battery. It sends power to parts of the car that operate while the engine is off, like the security system. Auxiliary batteries may also provide power to the engine start/stop system to ease the load on the main battery and alternator. 
Auxiliary batteries are primarily found in cars with diesel engines, as diesel motors crank at a higher amp and require a high-resistance load to start. But you can also find auxiliary batteries in hybrids,
electric vehicles
(EVs), and some luxury vehicles. 

How do I know if my auxiliary battery is faulty?

If your auxiliary battery is malfunctioning, you might notice some of these common symptoms:
  1. You have trouble starting your car: The auxiliary battery acts as a backup power source for the car’s electrical system, and if your primary battery fails and can’t supply adequate power, and your auxiliary battery is faulty, the stop/start function in your car won’t work.
  2. You notice leaks around the battery: The fluid in your battery is important to prevent battery cells from burning out. If you notice fluid leaking around your battery, you’ll need to get the battery replaced ASAP. Having this fluid leak into other parts of your engine can cause damage due to corrosion. 
  3. The battery light appears on your dash: A fully charged battery allows every component of a vehicle to function correctly. When the battery isn’t fully charged, these functions cannot work—or cannot work correctly. The battery light will usually illuminate when there’s an issue with the charging system.
The auxiliary battery lifespan for most cars is between five and eight years. If you have a vehicle between these ages that’s never had the auxiliary battery replaced, it may be time to have it inspected.
Remember: You can still operate your vehicle with a failing auxiliary battery, but it can put a strain on your primary battery, diminishing its life and necessitating premature replacement. 

How often should an auxiliary battery be replaced?

Auxiliary batteries deteriorate over time, but the extent depends on your vehicle and how well you’ve followed a regular
car maintenance schedule
. Most auxiliary batteries last between 5 to 8 years, though this can vary.
Once your battery deteriorates, it will put a strain on other parts of the car and you may notice certain functions start to fail. If you think your auxiliary battery needs replacing, head to the mechanic immediately. Failing to replace a dead auxiliary battery can lead to serious vehicle damage. 

Can I replace my auxiliary battery myself?

You might be able to DIY an auxiliary battery replacement if you’re confident in your auto repair skills. Not all vehicles have auxiliary batteries—but for those that do, the replacement process is similar to replacing an engine battery. If you’re not comfortable performing the process, leave the auxiliary battery replacement to a professional.  

FAQs

A faulty or failing auxiliary battery won’t prevent you from driving, but it can lead to complications with certain systems in your car, such as accessory functions not working.
A faulty auxiliary battery affects your vehicle's performance, causing errors in the electrical systems. If you have a faulty auxiliary battery and don’t replace it, it will interfere with the proper functioning of your car's electrical components and safety features.
In vehicles with a dual battery system, one battery—the starter or primary battery—is responsible for starting the car. The second battery—the house or auxiliary battery—is responsible for giving power to all of the accessory features when the engine is off, such as the audio system and the start/stop.

Meet Our Experts

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John Davis
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Car Expert
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Certified mechanic with 10+ years of experience
John Davis is an expert automotive writer and former automotive mechanic. John's work spans multiple categories, and he relishes the opportunity to research a new subject and expand his area of expertise and industry knowledge. To date, John has written more than 200 articles covering car maintenance and care, car advice, how-to guides, and more.
Prior to joining Jerry’s editorial team, John worked as a mechanic and freelance writer, creating content for clients including HotCars and SetPower.
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Jessica Barrett
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Car Expert
Jessica Barrett is a senior insurance writer and editor with 10 years of experience in the automotive and travel industries. A specialist in car insurance, car loans, and car ownership, Jessica’s mission is to create comprehensive content that car owners can use to manage their costs and improve their lives. As a managing editor for a team of writers and insurance specialists, Jessica has edited over 2,000 articles for Jerry on topics ranging from local insurance shopping tips to refinancing car loans with bad credit.
Before joining Jerry as a senior content editor in 2021, Jessica created visual content for clients such as Expedia, Vivid Seats, Budget Direct Car Insurance, Angie’s List, and HomeAdvisor. Her content was published in Business Insider, Forbes, Apartment Therapy, and the BBC.
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Kathleen Flear
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Car Expert
Kathleen Flear is an expert insurance writer and editor who heads up Jerry’s editorial team as director of content. Kathleen empowers drivers to make smart car ownership decisions through  best-in-class articles on insurance, loans, and maintenance. Prior to joining Jerry in 2021, Kathleen served as managing editor for a team of SEO content marketing professionals at Article-Writing.co and worked as a freelance writer and editor for a range of digital publications, including Chicago Literati magazine and Golden Words. She earned a bachelor’s degree in English language and literature from Queen’s University, and a master’s degree in creative writing and fiction from Sierra Nevada University.
*The price information provided on our car repair webpages is intended for general informational purposes only. Actual prices for car repair services may vary based on various factors, including but not limited to the make and model of your vehicle, the extent of repair required, and the prevailing market conditions. All prices for real repair shops are estimations based on our research only. Therefore, the prices listed on our webpages should not be considered as final quotes or binding offers.