New 2007 Prius, dead battery

[alibaba]

My husband and I bought a new 2007 Prius three weeks ago in Chicago. We drove it home and it sat in our garage for four days - it was very cold weather. When I went out to start it up on the 4th day it was stone, cold dead. I called the dealer- they hauled it away. They told us it was a defective battery- which was pretty disturbing. We waited for two weeks for them to replace it. We should pick it up tonight.

One of the mechanics said that whenever this car sits for a while you should disconnect the battery. I find this hard to believe and am doing more research.

Has anyone else had this type of situation.

Thanks, Diane

[auricchio]

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!

[Skwyre7]

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.

[Oxo]

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

They told us it was a defective battery- which was pretty disturbing. We waited for two weeks for them to replace it. We should pick it up tonight.

One of the mechanics said that whenever this car sits for a while you should disconnect the battery. I find this hard to believe and am doing more research.

[/b]

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.

[MegansPrius]

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

One of the mechanics said that whenever this car sits for a while you should disconnect the battery. I find this hard to believe and am doing more research.
[/b]

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).

[David Beale]

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.

[tumbleweed]

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.

[jangus]

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.

[ScottY]

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.

[Bill Lumbergh]

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.