12 volt battery dead - 2010 Prius

Yes, it is a conventional 12v battery, just smaller. I can't believe it died in just a week. I would at the least mention it to the dealership.
Was it outside? What was the environment like? Did you leave anything on (lights ,etc)?

 

:welcome:

IT can be catastrophic to reverse the polarity when jump starting, I assume the same for charging so be careful. Observe polarity. Do a complete search on the subject on Priuschat, BEFORE starting!

 

Normal jumping procedure, except you use the jump point under the hood instead of the battery terminal. You can, of course, jump to the battery, but to do that you have to crawl into the back and manually release the hatch.

Tom

 

Thankyou for the Thankyou! There is a long history covering various problems, procedures and causes with the 12VDC battery. It is vital that new members SEARCH in Priuschat first and read all the previous posts. All 3 (4) generations are basically the same in regards to the 12V system. With this knowledge one is better armed to discuss the peculiarities of Prius with a tech writer, mechanic or salesman. One lady with the assistance of a tow truck service totally ruined her inverter (a reverse polarity situ) and after weeks of struggle NEVER got satisfaction from her Toyota dealership and ended up selling the Prius at a additonal loss.

 

I left my car in the garage for over a week and had no problems with the battery. Maybe I was lucky.

 

You can keep the battery topped off with a "battery minder" type of device for AGM batteries. A normal battery charger or trickle battery charger will tend to overcharge and damage the battery if left on for extended times.

As for whether this is a "soft spot" for the Prius, the 12V battery is small, so it will discharge more quickly than a traditional large starting battery. That said, you should be able to leave your Prius parked for several weeks without any trouble.

There are two situations where the 12V battery will have chronic problems:

1) A dead or dieing battery. If you make a habit of leaving lights on or the car door open, your 12V battery will have a short life.

2) Short trips. The Prius uses a constant voltage charging system for the 12V battery. It is effective, but not very fast. If you only drive your Prius for very short trips, the charger will not fully recharge the 12V battery. In this case you should consider a battery minder, or perhaps make a few longer drives.

Tom


Tom

 

My 2010 Prius sits outside for weeks at a time in the cold of Western Pennsylvania and has never failed to start. One time it sat for over three weeks and started. There must be some problem with some of them because this issue has reared its ugly head many times.

 

I think the dealers are supposed to charge the batteries (new batteries often are not fully charged). When this is not done AND the car sits or endures short trip driving, batteries die young. Looking into battery minder options on another thread now.

 

Get it checked.

I left mine for over 3 weeks and it was fine. The only thing I noticed was that instead of unlocking instantly when I pulled on the door, it switched on at the first pull, then unlocked when I pulled it again.

After that, it started fine.

It may be that your car for whatever reason isn't switching to low power mode when you leave it for a few days.

 

My 12v battery dies after 36 hours. I had this happen several times after not driving my car for a bit over a full day. Turns out, it is because I leave the rear hatch up while it is in my garage. I have always done this with my cars to air them out since I have a dog. My other cars could be left like this for over a month with never a hint of a problem.

There are no lights on (I check at night when it is pitch black in there).

Has anybody else seen this? Does anybody actually think this is reasonable? 36 hours! A day and a half! Anybody have any suggestions on whether this is fixable, short of disconnecting the battery between drives? For now it means putting the hatch down but we have still left it up by accident now several times after caring arm fulls of groceries into the house.

 

If there are no lights, then perhaps disabling SKS might help. Perhaps the SKS is not shutting off when the rear hatch (or any door) is left open?

 

Why not roll the windows down instead of leaving hatch open?

 

Good advice, as a point of referrence, define "short trip".

 

Short trip as measured in time and not distance. For example, if you drive your Prius only 5 minutes per week.

There is time needed that 12V battery gets recharged fully. So if you do not use your Prius much, 12V battery voltage gets depleted to such extent, that during very short trips, it does not get enough electrical charge.

Another way of charging up your 12V battery beside driving or using battery minder, is to put your Prius into "Ready" mode, let's say for 30 minutes. Basically having it parked, but turned on, so that high voltage hybrid system is online. 12V battery will get its charge via inverter and internal combustion engine will run occasionally when high voltage battery voltage drops below certain level.

 

That would be a band-aid fix but doesn't explain why the car uses so much power when just sitting there. It also doesn't deal with the fact that both my wife and I have been known to forget to put it down after grabbing a handful of groceries. The good news is we aren't likely to do this except at home. It still feels like a broken design. But, yes, leaving the windows down would accomplish our goal of keeping the vehicle aired out.