How to Replace a Hybrid Car Battery

Hybrid vehicles combine the convenience of a gas-powered engine with the efficiency of a battery-powered electric car. The electric motor is powered by the battery, which is charged through regenerative braking and by the gas engine, plus some models allow for plug-in charging. The battery pack is separate from the 12-volt auxiliary or starting battery, and it contains higher capacity and higher voltage.

The OEM warranty for hybrid batteries is at least eight years or 100,000 miles, and eventually, it deteriorates and needs to be replaced. Replacing hybrid battery packs is more expensive than a traditional 12-volt battery, often ranging from $1,500 to $4,500 or more, depending on what you drive.

If you’re experiencing issues with your hybrid car and need to replace the battery, here’s what you need to know.

Signs the hybrid battery is failing 

Why do hybrid batteries fail? In most cases, it’s the natural deterioration of materials inside the battery cells, much like a car battery loses its capacity. An imbalance between cells can also cause poor performance and issues with charging, as can a jarring impact. 

There are several signs that a hybrid battery may be failing such as:  

  • Reduced fuel efficiency – If the hybrid battery is not working properly, the car may switch to gasoline power more often, resulting in lower fuel efficiency. 
  • Warning lights on the dashboard – Many hybrid cars have a warning light that will come on if there is a problem with the battery or hybrid system. 
  • Reduced power or acceleration – A failing hybrid battery may not be able to provide the same level of power or acceleration as a fully charged battery. 
  • Reduced electric-only driving range – If the battery is failing, the car may not be able to drive as far on electric power alone or it might not switch into EV mode at all 
  • Battery isn’t holding a charge – If the hybrid battery is not holding a charge properly, the car may not be able to start or may have a shorter electric-only driving range. 

Steps to change a hybrid battery pack 

First, a warning:  

There is a risk of serious electric shock from improperly working on or handling a hybrid battery, and damage can result to the battery itself. You should obtain proper training and certification to service hybrid cars before attempting a DIY repair involving the high-voltage battery. 

If you’re trained and equipped to replace the battery on your hybrid, tools and supplies you’ll need include:  

  • Insulated rubber gloves rated Class 0 1000-volt 
  • Eye protection 
  • An insulated socket and ratchet set 
  • Non-conductive wrenches and screwdrivers 
  • Trim tools 
  • Spill response kit for electrolyte 

With your tools and safety equipment collected, park your vehicle on a flat surface, set the parking brake, and begin the job. 

1. Disconnect the 12-volt battery

With the car parked and the ignition off, disconnect the 12-volt battery’s negative cable. If it remains energized, there can be an inadvertent activation in the electrical system that causes problems later. Depending on the battery location, you might choose to remove it altogether. It’s also a good time to check its condition and replace it if necessary.

2. Remove the hybrid battery disconnect

Hybrid vehicles are designed with a master disconnect that cuts power to the car from the battery pack. Check your owner’s manual for its location in your car, then remove it. Keep the disconnect in a safe place because you’ll need to reuse it with the new hybrid battery.

3. Remove trim panels

Most hybrid battery packs are in the trunk or hatch area, although they could also be under the rear seat. Once you’ve determined where it is, remove the trim panels that hinder its access. Use trim tools to prevent broken clips and panels, and always double-check for screws and bolts before forcing a panel to come off. Set them aside on carpeting or cardboard to prevent damage.

4. Access electrical connections

From here on, wear your insulated gloves to avoid the potential for a shock.

Locate where the electrical connections are at the battery pack, then remove them by carefully disconnecting the clips or screws. Tuck them safely out of the way so they don’t come into contact with the old or new battery accidentally while you work. These connections are usually under a protective shield that will need to be removed first.

5. Disconnect vent or coolant tubes

Before taking the old battery out, check around the complete battery pack and disconnect any tubes, ducts, or coolant lines that might be attached. These items could be damaged if you try removing the battery without disconnecting them first, adding cost and time to the job.

6. Assemble with the new battery

Place the new battery into your vehicle, then assemble everything you’ve removed in the reverse order. It’s a good idea to hand-start each bolt and nut before tightening them, otherwise, it could be difficult to get the last bolts lined up. Once it’s all assembled, install the battery disconnect and connect the 12-volt battery.

Replacing hybrid battery packs is a job best left to certified individuals. If you decide that it’s too big a job to tackle on your own, let AutoZone help you find qualified professional mechanics through our Shop Referral Program.  

Related Articles

FAQ/People Also Ask 

Can I replace a hybrid battery myself? 

It’s possible to replace a hybrid battery as a DIYer, but there’s an inherent danger in handling the high-voltage battery. It’s a job best left to certified hybrid technicians. 

How much does it cost to replace a battery in a hybrid car? 

A hybrid battery can range in price a lot based on the capacity and model, and whether it’s new or reconditioned. A new battery often runs $1,000 to $4,500 not including labor. 

Is it worth it to replace a hybrid battery? 

For a hybrid vehicle in good condition, a new hybrid battery can extend its life for another eight years or so, and it’s less expensive than buying a different car. 

How many years does a hybrid car battery last?

It’s debated how long you can expect a hybrid battery to last, but generally, 10 to 15 years is a common range.

How often do hybrid batteries need to be replaced?

The interval to change a battery varies based on weather, driving conditions, and usage especially. Most drivers see health decline between 100,000 and 150,000 miles.

Advice, how-to guides, and car care information featured on and AutoZone Advice & How-To’s are presented as helpful resources for general maintenance and automotive repairs from a general perspective only and should be used at your own risk. Information is accurate and true to the best of AutoZone’s knowledge, however, there may be omissions, errors or mistakes.

Be sure to consult your owner’s manual, a repair guide, an AutoZoner at a store near you, or a licensed, professional mechanic for vehicle-specific repair information. Refer to the service manual for specific diagnostic, repair and tool information for your particular vehicle. Always chock your wheels prior to lifting a vehicle. Always disconnect the negative battery cable before servicing an electrical application on the vehicle to protect its electrical circuits in the event that a wire is accidentally pierced or grounded. Use caution when working with automotive batteries. Sulfuric acid is caustic and can burn clothing and skin or cause blindness. Always wear gloves and safety glasses and other personal protection equipment, and work in a well-ventilated area. Should electrolyte get on your body or clothing, neutralize it immediately with a solution of baking soda and water. Do not wear ties or loose clothing when working on your vehicle.

FREE Loan-A-Tool® program requires returnable deposit. Please note that the tool that you receive after placing an online order may be in a used but operable condition due to the nature of the Loan-A-Tool® program.

Related Posts