Prius won't start...HELP

Yes, this is a dead battery.

No, unfortunately, you probably are not covered by warranty.

If you jump start it, do not use a running vehicle. Leave the donor vehicle turned off, or use a jump pack. Be very careful to make sure that you have the polarity correct. You must put the battery on a charger at 2+/- amps for several hours to have any hopes of saving it, otherwise plan on buying one from the dealer or the optima yellowtop.

 

Rajiv: The 12-v battery in the Prius is tiny. It does not need to run a starter motor as in other cars. The 12-v. battery only boots the computer. The computer then opens a relay to bring the big traction battery on-line, and that battery starts the engine (unless you have the EV switch and you tell the car not to start the engine).

If the 12-v battery is dead the computer does not boot up and nothing works. Get a jump, as seilerts says, and you'll be good to go. But since your car is a 2007, the battery could be on its last legs and you probably need a new one. Four years is about right for these batteries.

Ten days is awfully short for the battery to drain, though. You might have left a light on. If I'm not going to drive for a while (and I don't drive the Prius much any more, since the Tesla is more fun) I switch off the SKS (little button by your knee) and I make sure the headlights are turned off at the stalk and all doors are shut all the way.

 

You can save the labor costs by changing it yourself. It's not difficult to do and there are instructions here:
Toyota Prius 12 Volt Auxiliary Battery with install kit for 2004 - 11

Also, you can google for some videos which show how to do it. I find the videos are easier to follow than the written instructions.

Finally, be aware of this:
http://priuschat.com/forums/gen-ii-prius-main-forum/7912-dead-battery-auto-up-down-not-working.html

 

As you state, this one is waiting in the garage to be sold, seems the practical thing would be to follow Seilerts advice, and charge it for a while with low amp's, I would suggest overnight, or the weekend, and see what the results are.
Trickle chargers are nice to have, and many new ones have 'smart' technology so they won't overcharge, and you can use it with your other Prius in the same situation in the future.

If the battery does recharge, the future owner can then decide which 'new' battery they want in this Prius, as shown at this site, there are a variety of opinions on the matter.

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I think practicality depends on if it is being sold to a dealer or private party. If it's to a dealer, sure, get it working and the dealer can deal with it. If it's private party, a new battery could avoid a soon-to-be unhappy buyer.

 

A new Optima yellowtop would be a major selling point, IMHO. 12V battery is probably the #1 topic of discussion here.

 

Open the hood. Open the black fuse box on the drivers side. Find the red jump point near the upper left side inside the black fuse box. Attach the red (positive +) charger wire to the jump point terminal. Attach the black (negative -) charger wire to a chassis screw above the fuse box (any of the metal screws going into the body of the car). Turn on the charger.

When you use this method the car's electronics are exposed to the charger. Make sure you are using a modern charger of decent quality or damage may occur. Make doubly sure that you observe polarity (red to red, black to black) or you will cause damage of an expensive nature. If you are unsure, get a qualified person to help.

Tom

 

If your car is garaged or in an otherwise safe location, I think the easiest way is to leave the car on (Ready) to charge it. If you can't start the car, you can connect it to another car battery to get the engine computer on and then disconnect after that. I read on some post it takes about 8 hours to charge. This way you don't need to remove the battery, nor do you need a separate charger. Be sure to turn off climate control, headlights and anything else that drains the battery.

 

The failure of the fob is likely due to a dead fob battery. That is easily replaced.

 

One more note about attempting to recharge a severely discharged battery, time is a factor. The battery sulfates when at a low voltage state which is a bad thing (makes recharging less likely), so recharging should be done asap.

 

OEM battery MSRP recently jumped to $183.

elearnaid.com is now selling the Optima direct fit replacement for $170 + shipping (about $25). The Optima battery is a superior product, and elearnaid includes detailed installation instructions.

 

Another option if you like the Optima battery is to buy the Optima for your 2011 Prius and put the original 2011 battery in the car you plan to sell. That way you get a new Optima battery and the buyer of your old Prius gets a one year old OEM battery.

 

is there any easy way to tell if your 12v battery is going bad or if your alternator is bad?
Can it be done at home?

 

yes.