2006 Prius No Power but with Good/New Battery!

Once one of these sealed type batteries are allowed to discharge and stay flat for any time, they are not quickly or usefully recoverable. The original has probably deceased. A charger can't bring such a battery back from the dead. When you say new, how new is it?

The jump points under the hood are connected to the rear battery, so it is the same point electrically. But there are fuses that can be blown by having reversed jumper polarity applied, as has happened to a number of people here on PC. The AAA guys have done it in the past. Also, the AAA doesn't necessarily know how to test the Prius battery, so their opinion is not of any concern. Hopefully you didn't reverse the jump.

If you have a voltmeter, check the voltage of the battery in the back, and also at the jump points under the hood. If the battery is good, you should see >12.5V at both places. If you see voltage on the battery but not up front, then there are blown fuses at the battery. If you see something like 10V or less at both places, the battery has gone bad.

If you need help, Avi's Advanced Automotive is in LA somewhere, and is a Prius specialist. He posts here often.

 

Another item to check...has the 12V battery been replaced? An '06 with it's original battery would likely have a battery problem. A new 12V would probably fix the problem. Check that out.

Also, because of of the systems , key fob detection and engine imobiliser, etc. systems always draining the 12v, two weeks is about max for maintaining a good battery charge in the Prius. Because of these systems which are operating in any newer car, most any car will fail to have adequate starting power after a short time- the Prius because of it' s really very small 12v battery will last up for about two weeks with out being started and run to charge the battery. After all, the Prius 12v only has to start the computer system, not the engine so has a battery to match it's job. An ordinary car's battery has to crank over a very large engine, sometimes in very cold weather - of course they need much lareger batteries.

 

Yeah, sounds like the 12v is toast. Another way to check it is with this onboard test. Weird stuff happening? MPGs dropping? Test The Battery | PriusChat
Report back all three numbers. This is not a typical car battery so replacements are somewhat limited. All this jumping is very scary since it only takes one time connecting it wrong and for the repair to run into 4 ugly figures. With the SKS smart key system, not starting for a couple of weeks could kill the battery. Once it's been drained it is damaged and weakened. The SKS can be turned off with a switch on the dash under the steering wheel. But that wont help at this point. With a good battery, if it's not going to be driven for weeks a good practice would be to use a battery minder to keep it up. In any event, please let us know the outcome. We follow all these problems/solutions to add to our knowledge of the car.

 

It is not necessary to actually drive the Prius to get the battery to charge. You just have to make it READY, then it can be sitting in the driveway. However if the 12V battery was low, two hours is not sufficient. You'd have to leave the car READY overnight.

I suggest you go back to your friend, ask him to show you exactly what he did, and take a good sharp photo of the part. Perhaps he was wiggling the large fuse located in the battery positive terminal connector? That fuse or its holder might have a problem.

Prius does not have an alternator.

Answers to your questions:
1. The dedicated jumpstart terminal is located in the main relay/fuse box on the driver's side of the engine compartment.
2. Again, check the large fuse in the 12V battery positive terminal.

 

Check the ground wire connection for the 12 volt battery where it it joins to the body this comes loose or may have corroded.

John (Britprius)

 

...you could tell us your Dad's "new" 12-v batt type, but if it was standard Toyota batt once you lose charge, there is damage known as sulfating of the lead (Pb) plates. Here we tend to like the Optima Yellow Top replacement batt which should be better to handle deep discharges, but the same sulfating aging chemistry is possible. On a Gen2 you have a push button under the steering wheel to turn off the SKS (smart key system) when the car sits for extended periods.

 

Glad you've got it sorted. Sometimes it is the comparitvely simple things that prove the most elusive to find.

My history in electrical engineering (industrial automation and robotics) provided me with lots of challenges in fault finding complex systems where even a small fault can throw things into kayos.

John (Britprius)

 

I really appreciate you finding the problem, but could you explain where the ground dirty wire is?, and how they fix it?

 

I believe the problem was the 12V battery negative cable, either where it attaches to the body or at the battery itself. If correct, then the solution would be to inspect the cable, remove any existing corrosion, and tighten the cable at both ends.

 

Electronic repair seems elusive to many. You only can see the electrons with a digital volt ohm meter. What you measure is can be difficult to understand. This isn't meant to scare you, only to put you at ease with your new fangled electronic car. I repaired TV for 35 years and have seen many difficult repairs. It seems that a bad ground even messes up an experienced tech. A bad ground will cause all kinds of voltage fluctuations and no easy way to figure it out.

First, do all the simple things. Don't make a simple problem complicated.

Good checkout techniques help eliminate these troubles. First do a through physical check out of every connector or connection in the area of interest. Check fuses. I usually ohm the connectors that hold the fuses if possible. Fuses can quit working because the connector is corroded or burned (The fuse is good.). I also do a smell test. Burned connections and components are a give away on where the problem is. Next do voltage tests on the battery. Write down the readings. For the ground connection, use the ohms resistance reading, If you use 2 different ground spots that may have shown that the battery ground was bad. I like to check from the battery negative post to the ground wire ground connector and then go to the ground screw, that way you are checking the whole wire and connector. (Look or different values on the ohm reading.)

If that doesn't fix things then unplug and replug each connector in the area of interest, looking for bad corrosion.

I hope this helps in finding these problems.