2009 Prius won't start Strange short problem... Please help!

A new 12v battery is going to be close to 13v... The one that arrived for my friend last week was 12.95 volts out of the box... A used battery that's still viable should be 12.7 or higher at the jump points when the car is off.

Time to replace your 12V...

If it's earlier than normal for this and I had to guess you probably bought an Optima Yellowtop Battery, which isn't a real battery, it's garbage with no quality control and executives who think they can get away with charging up and reselling defective 12v batteries because their reputation from decades ago keeps people's complaints about their fraud in dispute.

 

Just to be clear, you're checking voltage at the jump point and at the fully connected 12 battery in the rear.

Did you check the 12v negative cable that connects to the body, is it corrosion free and secure at the grounding point?

 

You can try to measure the current drop, by connecting an ampermeter between battery + and cable +
Just remove the red cable from battery and put ampermeter between them...
I am sure you have some kind of short circuit...

 

Sounds typical. When was the battery installed, as you only have 24 month free replacement, then they prorate.

Were you charged for the installation before, and will they try and charge you for installation again with a warranty claim?

Figure out the prorated amount due, plus the install rate, and it might make economic sense to buy a better battery elsewhere.

East Penn makes decent batteries over many brands, or so I've read.

 

Do you have SKS?

There are two (2) sizes. If unsure of which battery you have, remove it (you'll need to turn it in for the core) and take measurements.

This could be the most 'bang for the buck' on a Group Size 51, with the additional 25% off : Bosch Premium Performance Battery Group, Size 51 | 647478 | Pep Boys

You could also call around to the usual big box stores, costco, wal-drip, etc.

AAA automotive batteries should still be made by East Penn, and depending on the warranty could be just what you need.

 

No, wrong conclusion.
IF you really did have that massive a short somewhere, there would have been a HUGE SPARK when you connected the second battery cable.
12.4 is NOT fully charged. The problem likely is that the battery is shot and the slightest little load drags it down past 6 volts.
It is also possible that one of the main battery connections is loose of corroded.
The first step is to charge the battery and have it tested.

AND....now that we are past that hurdle.....it is not worth your time or trouble to claim a few remaining months on your pro-rated Toyota battery warranty. Rumor has it that PEP Boys has a good one.

 

OK, so what happened to the option to DELETE ones own posts right after they are made ?

 

Edit yes, delete no? Don't recall the latter.

 

It is as Mendel said. If you wish to delete use the "Report" at the bottom left and ask (a moderator) to delete the post.

 

The battery manufacture date looks to be around November 2012. It's 7 years old.....Prorate would probably get 10-15 bucks...and that battery in the photo is the SKS model. 45AH. The small one is 35AH IIRC.

 

and yet, the op's first sentence says 'new battery'

 

that was just to throw us off the trail...

Anytime a car battery is 12.x volts when disconnected and then drops below 10 if connected to a car, there is a serious problem with the battery. Even a typical ICE starter motor will not cause voltage to drop that far on a healthy battery. That battery was dead as a doornail and I'd have bet a months salary on it. Another perfect example of why open circuit voltage is very unreliable for determining battery capacity.

 

Here's a link to a 55 amp-hour for $97 that my friends and I have been buying on Ebay of late. You won't find a better price on a 55 amp-hour. The terminals are a little different, so you'll need to buy some bolts that match the thread size and some washers on the top and bottom of your terminals in your car to hold them in place. 12 Volt (12V) 55 Amp (55Ah) VRLA AGM Sealed Lead Acid Battery 55 AMPS HIGH CAP | eBay

 

DOH.

Penny wise and pound foolish.
I hope this works out for you.......but the odds are against it.

 

i have to wonder if they are following the correct warranty procedure. i bought mine over the counter, and expect to return it over the counter if it is defective.