Where Is The Battery On A Toyota Prius (Prius 12V Battery Location)

Last Updated on December 24, 2022 by Leepu Da Maxim

Unlike most other vehicles, the 12-volt battery of the Prius isn’t under the hood; it is located in the rear of the trunk on the far right under a plastic molding. The Toyota Prius is a hybrid vehicle with two batteries: the 200 Volt battery that drives the car in electric mode and the 12 Volt battery that operates accessories such as radio and lights.

Key Takeaways

  • Toyota puts the 12-volt battery in the rear of the trunk because this battery is not intended to be serviced by the owner
  • According to Toyota, if this battery requires maintenance or needs to be changed then you have to take the vehicle  to a Toyota dealership or a trusted mechanic
  • If you want to access this battery then you have to open the trunk and remove the carpet
  • It is possible to jumpstart the Prius 12V battery but in that case, you will need a jumper cable and an assistance car

Overview of Prius 12V Battery

Voltage12 Volt
Capacity46 Ah
Battery SizeS46B24R
Height7 3/4″
Terminal Height8.63″
Cold Cranking Amps325 CCA

How To Access The Toyota Prius 12-Volt Battery

Toyota Prius 12 Volt Battery

The Toyota Prius 12-volt auxiliary battery is mounted in the trunk; it is a vented battery that you can even take its temperature. This section shows you the basic procedure for accessing the battery if you need to replace or remove it. However, we recommend checking the manufacturer’s step-by-step process found in the service manual of your specific vehicle. Doing this ensures you have everything you need

Below are the steps to follow:

1. The first step is to open the trunk and remove any floormat or carpet there

2. Remove the plastic storage cover/ bin to expose the spare tire

3. On the far right, in the rear of the trunk, you’ll see a plastic molding, unsnap this molding, then remove it to expose the battery. If you replace or remove the battery, continue with the following steps.

4. For the next step, you need to have safety glasses and gloves.

5. Unplug the temperature sensor 

6. Remove the negative battery cable using the 10mm wrench.

7. Next, remove the positive battery cable; ensure that when loosening the positive terminal, the wrench doesn’t touch any other metal part since it will short-circuit and cause a spark.

8. Unplug the vent tube on the left side of the battery

9. Then remove the bracket holding the battery in place and be sure not to touch the positive terminal with the wrench

10.  Hold the battery by the handle and remove it. 

How To Install A New 12-Volt Battery On A Toyota Prius 

Install A New 12 Volt Battery On A Toyota Prius 

After removing the old battery, you need to replace it with a new one to ensure the car starts appropriately and all electrical components are functioning in optimum condition. To install a new battery, you will need to repeat the steps you just did backward.

1. Install the negative terminal cable to the new battery and make sure it points in the same direction as it was previously

2. Put the battery into the floor cavity with the positive terminal towards the front of the car

3. Screw the negative terminal to the car’s body

4. Put the bracket in place and bolt it down, ensuring you don’t overtighten it as it can crack the battery.

5. Attach the positive terminal back in place

6. Replace the vent tube into the hole on the side of the battery

7. Replace and bolt the cooling vent for the main battery 

8. Replace the bolt controller and bolt at all three locations

9. Replace the plastic molding that covers the battery assembly

10. Replace hidden storage over spare tire and flooring

11. Replace carpets and floor mats

How Do You Jump-Start A Toyota Prius?

What do you do when your hybrid Toyota doesn’t start? Although the Toyota Prius convectional battery is located in the trunk, jump-starting isn’t different from jumping in a regular gas-powered vehicle. The model has a provision at the hood that makes it easier to jump-start the battery. You will need a jumper cable and an assistance car. Ensure your Prius and the assisting vehicle are parked and their engines are turned off, then follow these steps: 

1. Open the hood and remove the cover on the fuse box to reveal the jump-start terminal

2. Connect the red positive jumper cable to the positive terminal in your car and the second red positive terminal to the assisting vehicle

3. Connect the black negative to the assisting car and the second negative to an immovable and unpainted part of the vehicle’s metal frame

4. Start the engine of the assisting vehicle and allow it to run for at least five minutes

5. Turn the Prius power switch to ON and wait for the ready indicator before starting your Prius

6. Disconnect the jumper cables and allow the Prius to run for 10 minutes before shutting it off again. Doing this will enable the battery to recharge and prevent the vehicle from not starting later.

Signs Of A Dying Prius Battery 

Your Toyota Prius will signal you when you need a new battery regardless of your driving system. Always be on the lookout for the signs of a dying battery, especially in hybrid models. Schedule a battery inspection at your nearest Toyota service center if you notice any of these signs.

1. The gas-powered engine is straining or working harder than normal

2. Lower MPG

3. The battery bar has dropped

4. The state of charge keeps fluctuating

5. When you turn the lights on without the motor’s assistance, they appear dim

6. Your vehicle won’t turn on.

Frequently Asked Questions

This section looks at the most common questions regarding the Prius battery and answers them. We hope that any question you might be having is addressed to your satisfaction

Q. Why Is My Prius Not Starting?

The most common reason your Prius won’t start is that the battery is dead. Start by jump-starting the vehicle to see if the battery recharges. If this doesn’t help, we recommend contacting your mechanic right away.’

Q. Can I Use A 12V Battery Overnight Charger To Recharge My Prius?

You can use the standard automotive battery charger to recharge the 12V battery in a Prius, but you cannot use it to restore the large high-voltage battery that makes the car move

Q. How Long Do Prius 12V Batteries Last?

According to Toyota, the 12V battery on a Prius should last 100,000-150,000 miles or eight years, but most users have reported the battery lasts for five to six years depending on where you drive and your driving habits.


Hybrid cars are a widespread technology, and people love them for their fuel efficiency and environmental friendliness. However, these cars are different in appearance from gas-powered cars, and some things on them are such a puzzle for new owners. The location of the 12V battery, for example, isn’t so straightforward. You need to read the owner’s manual or articles like this one for you to locate and change the battery successfully. We hope this information comes in handy to help you give your Prius battery the care and attention it needs.