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Special 12V Battery for 2004 Toyota Prius?

Having needed a jump two times in three weeks, I figured it was time for a new battery. Brought it to the dealership since it had a recall out anyway, and they’d quoted me $109 for the new one, which seemed reasonable enough. But then of course, when I actually spoke to the service guy, he said that was the wrong price, this is a special battery and it would be $369 installed (including one hour’s labor!). Due to the rest of the bogosity they were spouting, I’d like to just do the recall and take it to my friend’s beloved mechanic for the battery and have him check the other things they were mentioning. Question is, does the hybrid really require a special 12V battery? I’m not talking about the big batteries, just the one that starts the car. And is that difficult to install? He hasn’t worked on hybrids before and is a little hesitant. Thanks much!

It is a special 12V battery, you might go to a Prius forum like Priuschat for more info on where to get one at a good price. And this battery does not start the car, it keeps the 12V accessories running. The main battery starts the car using one of the large electric motors. There isn’t a separate starter motor.

Hmm, interesting. A Prius has a huge battery pack. But the gas engine does not have a traditional starter? I am not sure what the motor output is even connected too? Does it have a auto trans or does the gas motor drive a generator which than powers elec motors that move the car?

There’s a planetary transmissions that connects the two electric motors to the gas engine and the wheels. Lots more info here:

Thanks, texases, for the answer and the speed! If the 12V doesn’t start the car (sorry, I’m a bit of a car idiot), does that mean my starting problems are maybe due to something else? I’ve been assuming no problem with the main batteries, especially since once it’s started the main batteries show lots of charge. The dealer said the alternator is fine.

It still could be the 12V battery, that runs lots of accessory systems that could interfere with starting (maybe the computer? I don’t know). So if your 12V battery is weak I’d replace it first, see if that solves the problem.

Actually, seems like Amazon has as good a price as any: $189 including ground shipping. A local NAPA dealer sells it for $229. But still need someone to install it if my friend’s guy doesn’t want to… I’ve had such bad luck with mechanics, though fortunately I’ve barely needed one for the last eight years since I’ve had this car. Maybe I’ll try looking one up on this site!

Special only in size dimensions and the fact that it is sealed and vented to the outside.
Also check your parts stores in your area. Mine are saying it may take up to 45min to install ( it’s in the trunk ) but many parts stores will do this for you.
Auto Zone, O’Reilly’s, Car Quest are the ones I have to check and all of them in this small town do not stock the one for the Prius but can order in overnight.

Thanks, Ken. Yeah, the AutoZone near the garage I was hoping to use sells them for $229. I think I’ll go with the Amazon deal and my friend’s mechanic. Should be about the cheapest, I trust him and It’s worth building a relationship as the car is aging. Thanks to all for your help.

If Auto Zone will install the battery for free, that might be the best way to go.

Other Prius owners have found ways of using a more common battery…It involves a little “fitting”…See the Prius forums…

If this battery is not involved with engine cranking, replacing it might not solve the problem…I would at least expose the battery so it can be tested…

@Anomy that $189 amazon battery will need to be installed. You’ll have to pay someone a few bucks to do it. Don’t expect that “friend’s mechanic” to warranty any battery you bring him.

So, just a quick followup from the original poster: Got the $189 battery (which actually comes with a 3-year warranty) and my friend’s mechanic installed it for 30 bucks. He also checked the other issues the dealer had flagged and assured me they were fine, though in one case he suggested I check it again in another 7500 miles or so. No problems so far. I actually was holding a grudge enough that I called Toyota corporate to let them know that this dealer at least had completely lost my confidence. They said all the right things and assured me I should receive a followup call from the dealer within 48 hours. A week or so later, guess what? No call.