Master Warning light (problem light)

Did you replace with Optima Yellow Top 12volt? If so that might be your problem, they resell bad batteries that get returned as if they're new...

 

Any chance oil is overfilled?
Check the dipstick, post a pic of it here.

For under $75 you could have tools ti check and clear error codes plus much more detailed hybrid data.
- Android phone/tablet
- OBDII ELM 327 Bluetooth adaptor
- Torque Pro app

Would be helpful to be able to see how the battery modules are doing when car is running. The adaptor plus torque pro app can help you with that

Then you would not be guessing what is wrouw and have some hard data.

I'm sure AutoZone can check your 12v for free as well.

The reality is you have a hybrid battery that is over a decade old. A DECADE! There is a high likelihood that is has failed. So hopefully you have a spare $2,000 - $3,000 allowed for that.

Maybe it is not your hybrid battery. But you'll need to supply a bit more data if you want to reduce guessing.

Feel free to call me any time if you want to talk through some more troubleshooting ideas.

 

I believe you have a failed inverter pump, if your ac stops getting cold when the warning comes up, then it's mostly likely the inverter pump

The problem will go away in the morning and will reappear when the car is hot again

 

For inverter pump you can Google it and find videos on how the turbulence in the inverter coolant reservoir should look.
If you peek in there and the water is calm, that's a pretty good indicator of a problem. You can also feel and hear the pump if it is operating properly. Basically reach your right hand down and feel the hose. It should feel like there is coolant flowing past.

 

if the master warning light came on, you have trouble codes, but auto zone does not have the correct scanner.

 

It might not show on many scanners once the car cools and triangle goes out

 

Or... if you have a bag of ice you can put it on top of the inverter and you might be able trick your car into thinking that it's always morning, at least for a little while. The water pump replacement isn't much different than a water pump replacement in a regular car. And it's way cheaper than replacing your power inverter that the pump keeps cool.

It's a relatively easy DIY job, or just a couple hours or less labor charge from an experienced mechanic.

 

I need to replace my 12V battery and had the yellow top Optima battery already in my cart until I see this...
My questions: 1) Is there any way to be 100% Sure that you are getting a NEW battery instead of a refurbished one? 2) What other 12V batteries work for the Prius? I would really appreciate any help you could offer. Thanks.

 

I think optima has increased their price significantly the past couple years. I would think getting an original battery from your local Toyota dealer would be the same price.....or less. Many dealers have parts they sell online, if you can find a local dealer that has online sales, you can have them match the online price and pickup locally at their parts counter.

I think there is a standard format for dealers that sell parts online. My local dealer is parts.longotoyota.com. So your local dealer might be a similar format. The part you want is
00544-21171-325 (with smart key) and is $183.00 online
28800-21181 (without smart key)

 

Thanks, I'll check that out.

 

Here's the ones my friends and I have been using... Under $100 with 15 more amp hours than other Prius batteries. You will need some big washers on both sides of the terminals and longer bolts to properly mount your Prius battery cables.

12 Volt (12V) 55 Amp (55Ah) VRLA AGM Sealed Lead Acid Battery 55 AMPS HIGH CAP | eBay