New battery, cold weather, Gen2 won't start

the battery is defective, the car is fine. a prius barely maintains a good battery at 12.x volts, it ain't gonna charge a dead one in 20 minutes, or 20 hours.

look at the battery warranty and return it

 

First, it takes more than 20minutes to charge a discharged 12v and investing in a quality 12v battery charger will be worth it in the long run... Second, I'd be willing to bet you bought an Optima yellow top 12v, which isn't a real battery, just fake battery sold by a criminal operation in Mexico.

 

Best to always check the voltage at the jump points under the hood, the same place you should jump start the vehicle from.

That reading was with the vehicle in 'Ready' mode, which means the dc/dc converter is working with a measured voltage of 13.78v
Check the 12v at the front jump points when the vehicle is turned off, if the 12v isn't making it up front, then the vehicle won't ready.

You could have a loose connection at the 12v battery, also check the 12v ground strap where it mounts to the body for corrosion.

 

is there any chance you accidentally left a light on when you put in the new 12v a few weeks back?

 

It sounds like a loose connection in the 12V somewhere.

 

In addition to all other points. It would take a minimum of 8 hours for the prius to charge ur 12v battery if it is discharged

Posted via the PriusChat mobile app.

 

I don't know if that is true for your Gen 3 but you are posting in a Gen 2 forum and it would take at least double that time for a Gen 2.

 

It depends on the charger... I'm glad I finallly stopped using cheap $10 trickle chargers than can take days... Now have a cheap $30 charger that can pump up to 8amps and is fully automated to send the most optimized amount of amps depending on the state of charge and that device can do a full charge of a mostly drained battery in 8 hours.

 

My comment was based on the OP's questions about charging using the DC/DC converter which certainly would not be done in 8 hours. I do agree that getting a good appropriate current (3 - 4 Amp) charger for the stock OEM battery is a better solution than charging in (and by) the car.

@PriusCamper, you need to tailor your advice to include the fact you are not using the OEM battery, so what is appropriate for you and your situation is not general advice for a Gen 2 Prius with an OEM 12V battery.

 

Aftermarket 12v AGM batteries are in no way different than OEM 12v batteries, other than being slightly higher quality...

 

If you say so. So every single aftermarket AGM battery is slightly better than the OEM? Oh, except for the Optima yellowtop, right?

 

As per frequent discussion the amp-hour rating for a Prius battery is more important than cold cranking amps rating. There are plenty of batteries that are both better and worse than OEM...

I bought my battery for $100 and put it in my Prius in Jan2013... It's still in the car and still works pretty good because it has 55 amp-hours. What's more I've bought a 1/2 dozen of these for other Prius for $100, also without issue: 12 Volt (12V) 55 Amp (55Ah) VRLA AGM Sealed Lead Acid Battery 55 AMPS HIGH CAP | eBay