2010 Prius will not start after sitting for 6 days in snow

As has been mentioned before, a new off the shelf 12V battery is not necessarily a fully charged 12V battery. The symptoms you describe still point to a weak 12V battery. Autozone should have a Multi Meter capable of measuring voltage at the under the hood jump points for $20 or so. Your first step in solving this should be to confirm that you are getting 12.5V or more at the jump points. If that checks out, you will need to have the codes read, probably at your Toyota dealer.

 

is the dash lighting up? any warning lights?

 

I would take the new battery back and have them test it. A battery can have a good voltage reading and still not put out the CCA (Cold Cranking Amps) needed to start a car in cold weather. Check your connections both at the battery and follow both leads as far as you can and check you have good connections.

One of these can help you determine battery voltage.
http://www.amazon.com/Car-Charger-Smartphone-Temperature-Fahrenheit/dp/B00SWGWILI/ref=sr_1_3?ie=UTF8&qid=1515460912&sr=8-3&keywords=car+voltage+meter

Just plug it into your cigarette lighter or power port.

 

The "cranking amps" needed to start a Prius are around 30, if I recall correctly from some datalogging done by PC member hobbit. In cold weather, though ... 30.

-Chap

 

The 12v battery does not actually start the car, your high voltage (HV) battery does that. The 12v runs the computers and network, including a computer and contactor in the HV battery which must function to achieve "Ready" state. It's possible the HV battery is reading too low but perhaps that will change when it warms some. I have heard of people who simply try to "Ready" the car several times and then it "starts" by going to "Ready". However, taking it to a dealer is probably the only way to determine the issue. Even with a special purpose code reader, you are likely to find many codes, most of which are meaningless until the primary cause is found.

PS: This thread is actually in the wrong section of Priuschat.

Here's a good enough meter for $3.97 from Harbor Freight and even has a backlight
Item #92020
Digital Multimeter - 7 Function, w/ Backlight

 

I agree that you need to check your connections, particularly from the battery's negative terminal to ground.

It is my understanding that CCA are not that important for Prius batteries, since the 12V does nothing more that fire up the computers. The HV battery starts the engine. It is true that all batteries lose power in the cold, but a Prius 12V battery should be less susceptible to cold problems than would batteries in cars that have a regular starter. The posts you will find relating to 12V issues in this forum all reference voltage measurements rather than CCA. I believe voltage at the jump points is all you need to measure.

 

While not a solution, this video is well worth your time to actually understand the significant electrical components and their relationships in a gen2 2004-2009 Prius. The college prof explaining this uses real parts and has other videos with even more detail.

 

Be warned if you jump incorrectly, it's $$$$. Find someone who knows about cars and knows how to use a multimeter (shouldn't they teach that at junior high?).

 

you didn't say if it was the original battery. if it was, it was probably bad. now, replacement should have fixed it, except you have to cycle on/off start button twice before it works. now, if the replacement battery is bad and/or it was installed incorrectly, it won't work, hence the advice to use multimeter.

PS: now I see radio works, check if headlights work too. maybe you need cycling on/off a few times?

 

A neighbor who is available and willing to help is nice to have. You need to be very careful when trying to jump start a Prius from another car. One false move can result in very costly damage to the Prius' electronics. Most people would recommend turning the other car off before attempting to jump the Prius, because very little current is needed to fire up the Prius' computers and an excess from the other car's alternator will at the very least blow the fusible link (about $100 from the dealer), and at worst fry the inverter (about $4,000 from the dealer). If you or your neighbor know the proper procedure for hooking up the 2 batteries in parallel, and are careful not to short the cables against themselves or any other part of the car, you can attempt to jump start your car, but that may not solve the real problem anyway.

I'm guessing it is still cold where you are located. If all the lights and accessories on your car seem to work normally, the problem may be that your High Voltage battery does not have enough power to crank the engine. The cold will reduce the power available to that battery as well. When you last were able to observe the HV battery's State of Charge on the Multi-Function Display, how many bars were showing? Given that your car is now about 8 years old with the mileage it has, a HV battery failure may be a possibility. If that battery has become discharged, it is really only your Toyota dealer's special charging equipment that can bring it back to life, and that is dependent upon the individual cells remaining in a balanced condition. I hope for your sake it is not the HV battery that is at fault, but I believe that is a possibility that needs to be considered, especially if the engine still will not start even with a jump.

If you tell us where you are located, possibly one of the more knowledgeable members on this forum may be able to come by and help you read the codes the car is throwing to get a better idea of what is wrong.

 

If they have a code reader, it may not be able to read the Prius-specific codes for the Hybrid system. Many third party readers cannot. The dealer's Toyota Techstream software can read them along with any detail codes.

 

So you have a new 12v battery, have no one around who has a voltmeter (lots of old people have them and know how to use them), and the Toyota dealer is a long ways away. A voltmeter from Harbor Freight or any Walmart or Auto Supply store will only tell you the voltage of the 12v battery. It should be at least 13.5vdc, if not a jump might help. Jump directly to the battery since you know where it is but be careful as a wrong connection can ruin the car.

You need a very special code reader to read the Prius codes. Even then it won't fix it.

Check your car insurance for towing options, many have towing as part of the deal. Call them. If not, call around to tow truck drivers. Negotiate with them if possible to take the car to the dealer. Any tow truck driver will be able to jump it and will try that first.

 

is there a chance your neighbor initially hooked it up incorrectly, realized the mistake and switched back?
if so, it'll be expensive to fix and Toyota place or a hybrid shop is your best bet.

ps: does anyone remember symptoms of reversed polarity in a prius?

 

good advice, except for the 13.5V part.

 

When it's on it should be at least 13.5 v. That says the inverter is charging it.

 

assuming prius is in Ready state. it's not the case here.