12 volt battery failing after test, how hard is it to replace?

Plenty of people have done the job themselves, myself included. It is not a hard job if you are a reasonably handy person, but is does take more time than some cars as the battery is in the right rear fender and you have to take some bit and pieces to get at it. The first time, it could take you about 45 min to an hour, but the second time on it would only take maybe no more than 30 min start to finish.

This video shows an obviously experienced guy doing the complete job in under 5 mins. It is unfortunate, that he gets in the way to see a couple of key things, like reattaching the earth strap, but if you have a few clues, you'll be ok. On the whole it shows the sequence very well.

You can do the job without the power tools, and a word of warning, make sure you use a magnetic extension (or use some other method, e.g. put a cloth down) to ensure you don't drop the bolt when re attaching the HV battery vent duct. It can take a long time to fish that out from under the battery.

Good luck.

 

45 minutes, after you watch the youtube videos.

 

dorunron has a great thread on it.

 

ALWAYS disconnect the ground (-) cable first and re-connect it last in order to prevent accidently touching the ratchet handle to the frame while on the positive cable, causing a direct short and a spark.

Putting a piece of plastic or paper over the head of the bolt before putting it in the socket will hold the bolt in place to get it started.

 

How do you replace the 12v battery? | PriusChat

Read post #8 for detailed information that I posted. I did it in one hour. I am disabled and was able to do it.

With the right tools, patience and a little mechanical skill anyone can do it. The Gen III is even simpler.

Ron (dorunron)

 

Thank you bisco for saying that!

Ron

 

Ignore Ron's battery advice at your own peril. I ignored just a LITTLE BIT OF IT -- and paid the price.

 

i'll be sending people to your house soon.

 

I'm just a little curious, what "little bit" did you ignore for which you paid the price?

 

Thought his tip to remove the negative connection to the car body was wrong and was a waste of time, so I spent some 10 minutes struggling to remove the negative clamp from the battery while it was still in the car. Much easier to take negative clamp off battery once you have battery out of car. I notice Lucious Garage follows Ron's method, also.

 

You are getting a warning light your just not seeing it.

The car throws a red exclamation point upon boot up when the battery that low. Only there for a second but its the only lamp that's not lit on bulb check when you boot it. So you notice it when it appears. It lights upon anything below 11.2 i think. It does not log a DTC either.

Pretty hard to miss.

 

Or just unplug the 2 B+ wires on the positive assy. They just unclick and pull out. Big one and small one.

Take the red plastic cover off and depress the clips and pull. Now you don't have to remove the positive assy at all. Just leave it on and unbolt the one negative (no sparks now) on the chassis and pull the battery out. Tape over old bare neg post on old battery and take off the positive assy and move it over to new battery. New battery should have neg post tape over also as you move the pos assy over to it. Then after pos assy on new battery attach the negative wire to the neg post. Leave it a little loose on the post as the final tighten will be done after you adjust its position relative to the chassis attachment. Its tight in there. But this way no sparks anywhere. Which is why the factory made those cables unclickable.

Check condition of the plug connectors while your at it and maybe add connector grease.

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Hehe, I have done the same. Seeing it done Ron's way, I wonder why I didn't think of it myself. I guess all those "normal" battery changes I've done in the past must have imprinted the method.