New 2007 Prius, dead battery

I presume it was the small 12v battery that died.

The mechanic is wrong; nobody disconnects the battery for a four-day stint.

I suspect something much more pedestrian caused the failure, like a light left on or a door ajar. When you have the car again, check carefully to ensure that no lights are left on!

 

Sometimes the Smart Key can cause a 12v battery to drain. There are numerous threads about this issue. In short, the car uses power from the 12v to "look" for the fob so it can be ready to unlock the car when you walk up to it. If it "looks" too long, the battery can wear down far enough that it won't have enough juice left to start up the computer when you push the power button. For future reference, if you're going to be away from your Prius for a few days you could disable the smart key system. There is a button under the steering column. You'll just have to use the lock/unlock buttons on your fob like a normal person.

Although, four days is a bit short for this to happen, IMO. But the dealer could have been kind of right. You might have had a semi-defective 12v battery and four days was enough for the smart key system to drain the battery too much.

I do agree with Rick. No one would disconnect the battery for a 4-day time period. 4 weeks, maybe. And it could have been a door (or the hatch) that was left slightly ajar.

Enjoy your Prius, and welcome to PriusChat.

 

<div class='quotetop'>QUOTE(dstoneman @ Dec 19 2006, 02:29 PM) [snapback]364246[/snapback]</div>

I don't think much of this dealer. Assuming the 12V battery was flat, he should have brought you a new battery either on that day, or the next, and fitted it. Alternativey did he try to jump start the car? I had a similar problem when my Prius was new because I accidentally left a light on all night but it jump started fine the next day and has been OK for the past year although I'm now always careful to make sure it's locked at night, and also I switch off the cabin light in the summer. Locking it at night (I haven't got the SKS system) ensures that all doors are properly shut as it won't lock automatically if one is even slightly open.

 

<div class='quotetop'>QUOTE(dstoneman @ Dec 19 2006, 03:29 PM) [snapback]364246[/snapback]</div>

Which dealer? I'd like to know so I don't take my Prius to them for service. I live in Chicago and haven't chosen where to do my service yet (bought the car in a far suburb).

 

The most common cause of a dead battery seems to be the hatch. You have to slam it to close it completely, otherwise it can leave the interior light on, and that will drain the 12V battery in a day or two (just like any other car).

Anyway, no big deal. If they are giving you a new battery great, because one that is fully discharged will have some damage done to it. It will have a little less capacity each time it is fully discharged (from sulfation). It's also possible the 12V battery was already damaged during the time it was shipped from Japan and sat in the dealers lot with people testing the car but never running it long enough to charge it back up, causing it to go dead in an unreasonably short time.

The four day to dead is not normal. Note that it takes at least 7 days to deliver a car from Japan, and not many arrive here with dead batteries (and they don't disconnect them - they don't have time!). A Prius 12V battery in good condition should be fine sitting for a month or more.

 

I agree with most of the other posts. This dealer, or at least the people you talked to, are not familiar with the Prius. People leave this car for sometimes 2 or 3 months and when they come back it starts right up, just like most cars. Skwyre7 gives good advice about turning off the SKS if you are going to leave it for a long time, that would be weeks not days. Most likely something left on, you should try to find out what it was. This dealer may not be of much help.

Towing the car was not necessary, they should have tried to charge the battery where it was or just jumped it and got it started. Also the time to replace the battery was ridiculous, they should have had one in stock and it only takes 5 minutes to put it in and another half hour to find out why it was dead.

Suggest finding another place to have your car serviced.

Welcome to Priuschat.

 

I had a similar situation with my 2004. It happened several times before Toyota figured out that it was the JBL amplifyer located under the front passenger seat was defective. Apparently, the amplifyer was NOT shutting off when the car was turned off, therefore draining the 12V battery.

There is a white multi-pronged plug that plugs into the JBL amp under the seat (accessed from the rear of the front passenger seat) that the Toyota Service Manager showed me how to unplug whenever I was going to leave the car for more than a few hours. This would prevent the amp from draining the 12V battery while I was waiting for the replacement JBL amp to arrive and be installed. Once you start the car, just plug the wire back into the amp in order to use your stereo.

Good luck and don't fret... you are going to LOVE this car despite this minor issue.

 

I find this hard to believe too. I once left one of the the interior lights on over night, but that was during the summer. Next morning, it started right up. Maybe I was lucky.

I had been to trips for two weeks. When I was back, it started right up. So 4 days? Something else should be wrong, either a bad 12V battery or other sources of current drain.

 

I just left my Prius outside at work while deployed for 18 days to the lower-48. I came back last night and the car fired right up.

Defective battery is a possibility. I would have had them do a current draw at the battery to ensure something's not draining it.

 

I think I remember reading on PC that if you lock the car, something like a light that is on will go off so you won't drain the battery. I garage my cars and don't lock them but do pause long enough to make certain all the lights are out before walking away. But if locking is a sure proof way to avoid a dead battery, it's worth considering. Anyway, enjoy your new car and welcome to Prius Chat.

 

Howdy dstoneman

Incidentally, the 2007 Prius "fully loaded" is Package 6. There is no Package 9 2007 Prius. You must've turned the "6" over to "9" :lol:

4 days shouldn't have depleted the 12v accessory battery. I have several times left my 2004 Prius 2 weeks undriven without battery problems - my 2007 sat undriven for 4 days during a recent illness without problems.

It seems most Dealers have all the dome lights and the cargo area lights turned to full "OFF" when the car is prepped and delivered so you would need to set the dome lights to "DOOR" [3-position slide switch on each dome light] for them to turn on when you open a door; however, it's possible though unlikely that the dome lights, map lights or cargo light could have been full "ON" which could conceivably deplete the 12v [small] battery. That 12v battery is covered in the very back corner of the cargo area and is automatically charged by the Prius system when the Prius is in "Ready" mode ... it is about the size of a motorcycle battery. Other possibilities - a door ajar or as previously mentioned, the cargo hatch not completely closed.

 

I just purchased a new 2007 sunday, and after signing the papers, I noticed the dealership was trying to move a black package 6 prius from the showroom, and it was dead! I sure hope that doesn't happen to me...

-Alex

 

I seem to recall the PDI requiring the dealer to ensure the 12 vdc battery is properly charged with the THS Auxilary Battery Charger - which is made by Associated - before delivery to the customer. So much for that idea ...

Remember the 12 vdc battery is pretty small, about the size of a lawn tractor battery. If it was already partially discharged, due to the way the inverter/converter regulates output, a brief drive won't properly charge it. It's really best to remove the little battery and use a "real" battery charger to charge it back up.

The Prius is very easy to jump start, as all you have to run are the brake booster pump and coolant transfer pump. Once the high voltage relay receives the command to close, the HV battery takes over and you're on.

The manual provides the location of the underhood "jump" point, which should be in the main fuse/relay box next to the inverter/converter plastic cover. You could hook up a battery charger to the bolt and leave it on for 10-15 minutes.

The actual 12 vdc battery is located in the rear of the car, passenger side, next to the temporary spare tire well. Of course, the rear hatch is electrically released, so once the 12 v battery goes dead, you're SOL unless you don't mind folding down the rear seats and trying to get to the emergency hatch release.

I really hope you made a typo when you stated the dealer needed 2 weeks to source the 12 vdc battery.

 

I have let my Prius sit parked for 30-odd days (SKS off) with no problems. I have let it sit for two weeks (SKS on) with no problems.

But a defective battery is a possibility. Once you have a new battery, and are careful not to leave any doors open, lights on, you'll be fine.

It is possible to drain the 12-v battery fairly easily by leaving something on. And it is possible, but much harder, to drain the traction battery. This would require leaving the car on so that it first burns all its gas, and then continues to drain the battery after there's no gas to run the engine. Nothing is foolproof, but this is one of the most reliable cars on the road. Its weakest point will be, if you leave the headlights on, you'll drain the undersized 12-v battery more quickly than in a conventional car with a bigger 12-v battery.

 

<div class='quotetop'>QUOTE(jayman @ Dec 19 2006, 04:14 PM) [snapback]364372[/snapback]</div>

I noticed that my battery is half-charged. Should I take it in and ask them to charge it fully? I noticed this the first night I got the car (sunday)

 

<div class='quotetop'>QUOTE(YodaddyAlex @ Dec 19 2006, 06:41 PM) [snapback]364402[/snapback]</div>

Uh-I think there may be some confusion here. If I am telling you something you already know please forgive me but:

The Prius has two batteries, the high voltage or hybrid battery (also called the traction battery) is a sealed nickel-metal hydride battery which has a little over 200 Volts. This is the main battery that powers everything when the car is turned on. This is the battery which is displayed on the MFD and shows it's state of charge. This battery along with the engine are used to power the car. If it shows half charged that's just fine. It should not be fully charged except in special circumstances such as descending a long hill. This is not the battery which is being discussed in this topic.

The second battery is a 12 Volt lead-acid battery which is like a normal car battery but smaller, about the size of a lawn mower or motorcycle battery. It is usualy called the aux battery. It's function is to provide electricity when the car is powered down. If it is run down the car will not start because it supplies power to the relay which connects the hybrid battery to the car when you push the power button. This is the one being discussed here. There is no indication for its state of charge.

Hope that helps explain what is going on here-it's kind of hard to follow some of the discussions when you are new to this vehicle. It really is different.

 

I've let my Prius sit for >1 week idle w/o any issues. I've never turned the SKS off either.