2012 Toyota Prius Red Side Shot
Peter Neilson's picture

Can A Toyota Prius Run If The Battery Is Dead?

The Toyota Prius is simply one crazy awesome vehicle. Not only is it a great fuel sipping genius, but even when it is neglected. So what really happens when the traction battery no longer works? That is a great question, and we are about to find out.

When it comes to hybrids, there is not another company out there that has made more than Toyota. Through my adventures out on the road, I see them everywhere. Since there are so many, I asked myself a question. What happens when they all start to have the same problem with the hybrid battery?

To better understand this, I needed to first understand what the hybrid battery does, in order to see what happens when it does not work anymore.

What the Toyota Prius Traction Battery Does

The traction battery that we find on Prius is an energy storage device, as any battery is. It holds energy that can be used on demand. This energy is used to turn a motor generator inside the transaxle that either starts the gas engine, propels the vehicle at low speeds or aids in fast acceleration.

Toyota Prius Battery Block

The battery is responsible for an extra boost of energy that helps to make up the lack of power from the gasoline engine. This means the gas engine is smaller, and uses less fuel making it excellent for economy. The traction battery also stores energy that is being recaptured from the vehicle when it is coasting or in regenerative braking mode, which we can then use this energy in propelling the car forward.

Between these two examples we can see that the battery plays an important role in helping the vehicle drive and accelerate as a regular vehicle would.

What Happens When The Battery Fails

Should you encounter a P0A80 and have the hybrid battery fail, your Prius will actually still run, just more often. The car will still drive, but with a lack of power, as we do not have the needed available energy from the battery. The starting and stopping of the car will not be smooth as well.

Prius is a parallel hybrid meaning that if one of the components fails, the vehicle can still operate until it can be repaired properly.


The short answer to this question is yes,the Toyota Prius can still drive if the hybrid battery fails. You will get poor fuel economy and a rougher drive from it though. Should you encounter this issue, see you dealer or a qualified shop that can help you get it back into original driving condition.

I sure hope this helps anyone who has encountered a failed hybrid battery. Feel free to reach out to us on the Facebook group, Toyota Prius Owners Club for more help.

Check out tomorrow's story where I finally get to share my 2000+ mile road trip that I took in my Prius.

Peter Neilson is an automotive consultant specializing in electric cars and hybrid battery technologies. He is an automotive technology instructor at Columbia Basin College. He holds a Bachelor of Science in Automotive Service Technology from Weber State University. Peter can be reached on Linkedin and you can tweet him at The_hybrid_guy on Twitter.

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What is more common is a failed 12 volt battery. When that happens the car will not start or run because the electronics/computer does not have any power supply.
You Are A Genius. Not.
If the reaction battery completely how will the gas engine be started?
TL;DR: Not really. Impact can be mild to severe. A dead cell can result in "limp mode" where you basically have a 20 hp car, so 30-40 mph with the throttle pinned. Best case is as is described in this article, but the length of time between the mild issues described in this article and limp mode is usually short.
Battery could also catch on fire. Then the games is over.
You are wrong. As I have had two Prius and escape hybrid with battery failure. First you get the triangle of death then the car will run for a few blocks and die. It will restart then run a few blocks and die. It will not go above about 40. As the Prius uses the electric motor as the transmission it feels like a transmission problem. But it's the hybrid battery.
Sorry you are Incorrect the Toyota Prius (Gen1,Gen 2) Will not start or run if the Traction Battery is dead, Not sure where you are getting your Information from But you are Incorrect.