I've heard that if the Prius is not run for a couple of weeks (away on vacation, etc.) the battery dies. Does anyone know about this, and is there something that can be done if it's true?
The big NiMH traction battery won't die and can sit unused for many months. The 12V battery requires a bit more exercise, and in the early 2nd generation versions we would see it die after 10 days to 2 weeks if unused. Since those models I've heard nothing about a well maintained battery causing any issues even if not used for a month or more. Certainly it's probably best to start, drive and allow for a full recharge every couple of weeks, but you won't find your car dead at the airport after a couple weeks if that's what you're concerned about. If you will be leaving it unused for longer periods of time then a battery maintainer is probably in order to keep it from draining.
Thanks for the help. I just drove a new Prius III home today and someone told me about the battery issue, or non-issue as you've mentioned, thus my question.
Congratulations! There have been hints of some bad 12V batteries shipped with Gen3, and there have definitely been some 12V batteries drained and seriously wounded while on dealer's lots, in all models of cars, before delivery to customers. These buyers then start seeing battery problems prematurely. And a general problem with the Prius family is that 12V batteries that would be dead on any non-hybrid, keeping on working in a Prius -- sort of, and not completely trouble free. A failing battery in a Prius doesn't produce the familiar weak starter cranking of past cars, so drivers have to learn a completely new set of symptoms, some bizarre. That has lead some drivers to keep suffering unusual problems for extended periods, on weak batteries that would have been replaced long ago on any other car. Another real difference is that Prius has a comparatively small 12V battery, so an interior light inadvertently left on will drain it flat faster than on other cars.
The dealer I bought my 2010 from had it for almost a year and according to the Carfax they didn't drive it much. I'm surprised the original battery made it through all that sitting. I'll be switching it out to a yellow top Optima with the standard terminal kit as soon as it shows signs of deteriorating. I'm going with the standard terminal because Autozone stocks them and they warranty them in-store with minimal hassle.
I had a 2005 Prius until today (bought a 2011 and it sits in my garage this very moment). Anyhow, I have been away for 3 weeks to a month many times and have never had a problemwith the battery. Some people said to shut down the key search with a button under the wheel so as not to drain the battery. Don't know is those are on the 2010/2011s or not.
The SKS off button is no longer in the car. The GIII just shuts it down on its' own earlier (even the GII shut it off after some time).
:mod: Thanks for the information. I was most concerned with leaving it at an airport for a week and then returning to find a dead car! I don't anticipate extended trips more than a week. I just got the car yesterday; Prius III and so far it's terrific; 54 MPG. Hey I noticed your ID is Huskers. Are you from Neb? I went to school in Lincold and I am a Husker fan.
I wrote to you a while back about rehabilitating my prius battery (12v). I removed it, opened it, and added water (a lot btw), and it has run til yesterday. I was looking at all the info about the optima for prius... but my local Auto Zone says they have had problems here in Taos, NM at 7000' of the batteries freezing which ruins them. Do you have any knowledge about this? Alberta has to get colder than here. Thanks
There is way to force it to turn off. This is good if you are going to leave the car for a long period of time. If you search the forums there are threads that explain the process.
I'm not buying the statement that the Optima batteries are freezing, there are plenty of owners here that have been using the yellow tops in cold conditions with no issues, put the Optima in and save yourself some headache.
A charged lead-acid battery won't freeze down to at least -60C. The Optima is a lead-acid battery. I don't think Taos will get that cold. Leave one discharged and all bets are off.
The only problem I had with mine is when my 9 yr old left a dome light on or door ajar, but that has been a 12V issue with lights left on. Never had issues with the ion battery and I have a 2006. Many happy hours driving your new car!
