so I get a phone call from my wife today saying the car won't start. I run down town as she is stranded and sure enough dead battery. I called toyota and they sent someone out to jump the car and told her take it to the dealership. She gets there and they tell her she must have left something on but no worries they have it on the charger and it will be ok. I check all the rigs every night to make sure nothing is left on so I know it wasn't that. If she leaves her smart key in the car can it communicate back and forth with the car even though it's not running? I am wondering if its possible that may have caused the problem. Also does anyone know the size on the 12v battery? I'm a realist, if it went dead once it will do it again. I would like to just get a new one to put in it but toyota won't tell me the size and none of the books here at the parts store will tell me what it is.
You will not find an exact fit replacement at your local auto parts store because the battery terminal size is smaller-than-normal. The price of the replacement 12V battery at your Toyota dealer should be $139 if they sell parts at MSRP. I'm sure that the Toyota dealer parts counter clerk would be happy to sell you a replacement. If the Smart fob is left near or in the car that might cause a very slight current drain but if that was sufficient to provoke a no-start situation then your battery should be replaced anyway (or at least fully-charged to see whether that is sufficient to forestall future no-start events). How much use does the Prius get? If it is very lightly driven then maybe it would help to hook up a 12V battery charger periodically, like 2x a month overnight.
Only the Toyota battery will fit with no modifications, these guys have a kit that includes the parts to modify it. 12 Volt (12v) Toyota Prius Auxilary Battery for 2004, 2005, 2006, 2007, 2008, 2009 and 2010 with installation kit
We have only had the car for a week. She has put about 400 miles on it in that time frame. That should have been sufficient enough to hold at least enough surface charge to start the car I would think. I have been in the automotive industry for years now I realize these cars are different then what i am used to but, this screams bad battery. However toyota says its ok. I don't believe it though.
If you search on PC you will read of many cases where the dealer said the battery was OK, and it wasn't. read this tread: http://priuschat.com/forums/newbie-forum/73400-weird-stuff-happening-mpgs-dropping-test-battery.html
Dealers often use a PASS/FAIL tester with voltage limits good enough for a conventional car, but lower than what the Prius really needs. The thread above has an easy accurate procedure you can use yourself with no tools required.
But your battery is 3 years old & is due. I would give it a full charge then check the voltage readings on the MFD in Maintenance Mode. If they are low then swap it out. If you try starting the car several times (3-5? I don't remember what worked for me) on a dying battery you may be able to get it to start. That trip better be to buy a battery.
