2010 II 12 Volt Battery Dead After 17 Days of Parking

[lmeren74]

I have a 2007 Prius (with GPS and bluetooth). Recently - ~ 3 months ago - it wouldn't start after being in my garage overnight. I got a friend to help me jump it, and took it into the dealer; they kept it overnight and told me that they couldn't find anything wrong with the aux battery. Over the next month it occasionally wouldn't start: all the lights on the instrument panel would come on, including the big red '!' but the car wouldn't be able to shift into drive. Leaving it for a few minutes and trying again would resolve the problem.

One month ago, it wouldn't start at all, even with a helpful neighbour jumping it: lights would come on on the instrument panel, but the car couldn't move into drive. I ended up having to get it towed to the dealer (and got them to pay for it), and after keeping it overnight they told me that the aux battery was fine, was holding charge well within normal parameters. Their conclusion was that I didn't drive the car enough for the aux battery to charge up.

My question is: has anyone else heard of this? I drive ~13 miles to work each way, which is some distance. This week the car wouldn't start at work, and is now completely dead (I thought it may have been the battery in the key fob, and brought in the - unused - spare fob, but no response at all); the car can't even be locked using the switch on the inside of the driver's door. If I go back to the dealer they'll charge me for the tow, and probably tell me that I need to drive it more. This seems ridiculous for a car that's designed to be fuel efficient!

[qbee42]

There have been problems with short drives and the 12V battery. I would think that yours is long enough, but maybe not. Either way, it appears that your 12V battery may be getting weak. I would test it or replace it.

Tom

[itradegreen]

I have been working on this problem for five year as I have had these many problems in my 2005. And just today had left some meetings at US manufacture and found a few ways to "repair" the toyota prius 12 volt battery mistakes those engineers are not seeing how they messed up the producton of these items. Now since I have expeirenced these 12 volt battery problems now after 4 years of driving an 2005 anad I only have 28 thousand on it now! Any, soon I will let you know how my kit to repair the ongoing battery dain outs the prius people have become mad about and it has continued into. These battery problems will plague prius parties and as each day goes by and each prius with a battery becomes a day older the possiblities that they just have a "massive battery compication wich will keep you anxious everyday you are out there drving that amp heavy prius 1,2 & even the present 3rd generation.

[indianapens@msn.com]

Originally Posted by wfolta

Have them give you the service bulletin and please scan it and put it here in the forums. Otherwise, I'll say that your dealer is lying. There are no instructions to shut things down in the manual, though it specifically mentions that all lights are shut off after 30 minutes and the SKS shuts off after 3 days. (Did you leave your key in the car?)

Many of us have left our 2010's for longer than that with no problem.

The service bulletin is T-SB-0152-09 issued April 30 2009. It is titled "Maintenance for HV and Auxiliary Batteries".

It states "if the hybrid vehicle is put into storage, the state of charge (SOC) if its HV battery and auxiliary battery will gradually increase. To prevent the battery from becoming discharged during storage, proper maintenance is necessary.

Under "Maintenance Items" this bulletin states " To store for 10 days or more: Disconnect wire harness from exclusive jump starting terminal (found in Junction Block under hood) (Prevent decreasing SOC during storage due to parasitic current drain)"

No, I didn't leave the key in the car.

[tumbleweed]

In case anyone is interested here is a site 12 Volt (12v) Toyota Prius Auxilary Battery for 2004, 2005, 2006, 2007, 2008, 2009 and 2010 with installation kit and free shipping that will sell you an Optima Yellow Top with an installation kit for a 2010 Prius, $159 free shipping. I have not bought one of these and don't know anyone who has but it sounds OK and I thought I might give it a try if (when) I need a new battery. I think others have used the Optima in the Gen2 and it should work fine.

[RodJo]

Originally Posted by wfolta

Have them give you the service bulletin and please scan it and put it here in the forums. Otherwise, I'll say that your dealer is lying. There are no instructions to shut things down in the manual, though it specifically mentions that all lights are shut off after 30 minutes and the SKS shuts off after 3 days. (Did you leave your key in the car?)

I believe the TSB has already been provided (see Post #6 or, better yet, Post #12) and discussed in this thread.

[Prius5138]

Originally Posted by indianapens@msn.com

Left my 2010 Prius II at a parking facility in Chicago for just over two weeks. Upon return, the 12 volt battery was completely dead. After a $50 jump start, returned the car to the dealership for assistance. Their report:"everything is fine and this is common for the Prius as there are numerous computers that are running as well as SKS". BTW, SKS can not be easily turned on and off in the 2010 series.

According to the dealer, Toyota's position is that anything over 10 days of storage with no driver activity will result in a discharged 12 volt battery. Both the dealer and I looked in the owner's manual and could find nothing describing this situation, but apparently they have a service bulletin that covers it.

One possible solution when parking the car for an extended period is to disconnect a lead from the battery but that would require me to climb through the back seat area and manually open the hatch door to gain access to the battery to reconnect the lead. Another idea would be to pull a small fuse called the "short pin" located in the center of the main fuse box. Both ideas are rather cumbersome to say the least.

Anyone have any other ideas?

I am a relativley new and ignorant Prius 2010 II owner. I was away for 7 days and came back to my dead Prius and had to enlist friends to jump start it. A colleague who got the car the same time as me was away for 14 days and had no problems with her Prius.
I will be going away for a month soon and need info/help in disconnecting the battery - the instructions in the manual looks pretty complicated to me. And could anyone tell me where I could get one of those portable jump start kit? Thanks.

[PriusWoman]

If this a repeat I apologize in advance:

Quote from the 2010 manual:
"However, if the vehicle is left parked for a long time the hybrid battery will slowly discharge. For this reason, be sure to
drive the vehicle at least once every several months for at least 30 minutes or 10 miles"

[tumbleweed]

Originally Posted by PriusWoman

If this a repeat I apologize in advance:

Quote from the 2010 manual:
"However, if the vehicle is left parked for a long time the hybrid battery will slowly discharge. For this reason, be sure to
drive the vehicle at least once every several months for at least 30 minutes or 10 miles"

That quote makes perfect sense and that's how it should work. Anyone who drives the car once a month for a half hour or so should not have a dead battery if the system is properly designed. Problems could be due to insufficient charging capacity, sneak circuits that draw down the battery when the car is off, or Toyota is buying a lot of bad batteries, or all three.

Toyota really needs to look at this problem and come up with a solution, but don't hold your breath. Their modus operandi seems to be ignoring problems unless they think they will result in massive law suits.