2011 Toyota Prius - Battery?

My 2011 Prius suddenly did not turn on with the power button pressed. The auxillary power mode didn’t even turn on (that’s the initial power settings) and none of the power functions for the car worked at all (locks, lights, rear door) but the one thing that did show up was the check engine light along with some clicking sounds. I think this will require the 12 V battery being jumped but not sure if it will work.

I will want to get this taken to a mechanic that knows Prius’s pretty well - is there a mechanic near me that can work with hybrids or knows them mechanically well? (I live in Medford, MA)

Sounds like the 12 volt battery. AAA could check that for you if you are a member. It’s free. Not super close, but Advanced Automotive on Woburn St in Wilmington is great. The service all of our cars. (About 5 minutes north of you just off 93 at exit 40. Be well.

Jumping may not work, it didn’t on my hybrid MKZ. How old is the 12V battery? If it’s more than 3 years, I’d just replace it.

Likely you need to replace the 12V battery.

Do not try to “jump” it, you do not want to damage the fragile electronics with any kind of voltage spikes.

Replacing this battery is a simple DIY job, instruction can be found on YouTube, search for “Gen2 Prius 12V bettery replacement” or so. You do not need “certified Prius specialist” to make it happen.

I replaced mine with some decent brand from AdvanceAuto, it was cheaper than dealer’s price and not only it made for reliable starts, but engine started to work “smoother” and MPG improved. You will find similar feedback on Prius-related forums, the magic here is that old battery is not working as electric system buffer anymore and it makes for substantial electrical “noise”, disturbing normal operations.

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Be prepared for sticker shock

12V batteries for Priuses are typically VERY expensive . . . even decent aftermarket batteries

highway robbery in my opinion, given the size of the actual battery

It’s not inexpensive, but not that bad either:

That’s Advance Auto.

You can always find a 25-30% off coupon for online shopping, buy it with “18 minutes in-store pickup” and be done.

Advance Auto Parts typically installs the battery as well if you can get the Prius to their store. If you can do that, they will just keep the old battery. Otherwise, you will need to bring the old one to them to get the core charge refund.

Yeah, that is expensive. I buy my replacement batteries there an I usually pay about $120 after returning the battery. It’s not AGM, BTW.

I’ve bought group 49 AGM batteries for less than that price . . . decent ones with 3yr free replacement period, not junk

And it was very recently

A group 49 battery is huge, next to those little Prius batteries

So therefore, I think the Prius 12V batteries are overpriced by a lot

The only reason I can think of the expense is this . . . it’s probably a slow-moving item, compared to other 12V AGM batteries for non-hybrid vehicles. Therefore they charge a lot more?

Yes, indeed they are slow-moving item.
Mine was 8-years old when replaced, my coworker had his to last 9 years on him.

Unless you forget your interior lights on, this is pretty hard to kill these :slight_smile:

BTW, on my 15-years-old Prius I replaced all these lights to LEDs as some started to burn down or look like they gonna burn (glass sputtered with evaporated metal from inside)… these are incandescents and replacing them to quite cheap LEDs both added brightness and reduced the draw