Dead 12v, ticking noise

If the car can be jump started, then your issue is probably with the 12v battery. If you have a receipt for the original OEM battery, they have a long warranty. I'm assuming you are talking about buying this from a Toyota dealership. If you did not buy from a Toyota dealership, then I would now know if there is a warranty. You can bring it back to Toyota for a warranty claim, if the dealership you purchased from is a Toyota dealer.

 

If you want to start diagnosing, I'd start by getting a multi-meter like 7-Function Digital Multimeter set to 20 volts and see what the voltage reading shows. If the read is below 12 volts - next step would be to have the battery load tested at AutoZone, NAPA, Advanced Auto or other part dealer that does the load test for free.
If it fails the load test you should be able to get a pro rated new battery using your receipt.

That doesn't tell way the newish battery failed to start the car so soon after being replaced, but it's a start and with your new multi-meter you can keep track of the battery voltage more closely.

 

prius doesn't have a conventional starter motor.

the 12 volt boots up the computers, and closes relays to the hybrid battery

the hybrid battery powers the motors in the transmission which spin up the engine.

if the car doesn't go into ready mode (ready light on dash) it's likely the 12 volt. a small charger is a good idea, but if you don't drive much, a maintainer should be used, and a jump pack is always handy.

 

The offstage current draw is usually 15-40 ma (thousand of an amp). Typically a good 12v battery can supply that much for three or four weeks, not just three days.

A failing 12v battery normally has low capacity, so the auto supply test can determine if that is the cause. Not all load testers are created equal, ideally you want an old school resistive load tester.

The other thing that kills a battery in 3 days is excessive parasitic draw, perhaps 100 ma or more. High parasitic draw is caused by some device not turning off completely, often traced to an aftermarket radio, gps or something plugged into the obd2 port.

So if the battery checks good then have someone run a parasitic draw test.

 

Todd should be able to answer those questions for you.
Schumacher is a great brand, as are battery tender, noco, and others.
I’m not familiar with the gen 4 (2017-2022) Prius battery, but you don’t want a charger that exceeds the batteries max amperage.
Todd should know.
Yes, charger and maintainer in one unit.
A jump pack is a small lithium battery that you plug in to charge, and then keep in the car for emergency jump starting.
If you have a good battery and drive most everyday, you shouldn’t need it, but some like to carry one all time for emergencies

 

I was recommended here a battery monitor. Something like this. I quickly found I don’t drive enough time to keep the battery charged in my Prime. This one is on sale I just ordered one seeing the price. Keep tabs on the battery with a phone. Watch it charge as drive if want to. Click link to see the price, under $15.

 

@Mr.Vanvandenburg that's a neat gadget with what looks like in the spec as a 1.5 mA parasitic draw.

It would be one of the questions I'd ask Todd at Tampa Hybrids about.
Not only due to there possibly. already being voltage and temperature sensors already already mounted on the 12 volt battery, at least with the Prius Primes and possibly with the Gen 4 regular Prius too.
Todd might also know the best way to monitor those sensors in our Prii.

 

I got the advice from Salamander, best advice so far from this site.
1.5 ma = .0015 amps, 1000 hours X .0015 = 1.5 amp hours withdrawn from battery over appx 40 days. Not an issue.
The one I got first on Salamanders link was 1.5 also. I think the description said 1 ma. I got the same exact one later for under $14, returned the first one. Bought a second different one. Bought the one here as a third one for daughters hybrid Camry. All cars have one now. No more lifting the heavy hood of the 96 Toyota truck. She has been putting the charger on every day, not knowing where the soc stands. Now just set the app to alert at a certain level.
I have to fault Toyota for not making the dc to dc converter charge fast enough for all drivers.
If a newer battery is just discharged and charges back, it isn’t necessary to get a new battery.
If it was me, I would get a charger maintainer and a battery monitor, all done.

 

I hope I didn't offend. I'm aware that the Gen 4, Gen 5 - 12 volt system is not well documented and monitoring it is even more cryptic. It's seems to me and a few others (not all currently posting here ) that normal draw on the 12 volt system has some unusual properties that knowing the best ways to monitor it can save a lot of time, $ and frustration.
Old Gen 4 thread about the 12 volt system
12v Battery Is Discharging, Re-Charge Now ! | PriusChat

 

Whatever I wrote, it wasn’t supposed to post. No offense. I deleted, walked dog, then rewrote above. Maybe I said something, sorry if so. Now have more to read, but also life is waiting. I feel problem solved for me. My battery is now about 65% soc, and it was about 4 days ago I charged it to full, should mark it down. As I drive I can see the charging but it isn’t fast enough for the time car is driven. It doesn’t tell the number of amps charging which I would like to see. Like the old ammeters on cars showed. Yes, there were smart people back then, and it didn’t require a cell phone.

 

congrats, all the best!