12 volt battery

I've just recently had the same problem as many of you, with a 2009 Prius -- just less than a year old and 13k miles. We took our Honda on a trip for a week and returned to find the Prius dead as a doornail!

I charged it up with an ordinary trickle charger and it's run fine ever since. I don't think this would be a good car to leave at the airport when we travel out of the country for a week or more!

One think I think strange: no one but Toyota sells a replacement battery! The guy at Batteries plus says this is because the battery has special venting/valving and this may be Toyota-patented. Has anyone found a reliable non-Toyota source? A little battery like this shouldn't cost $150+ that Toyota wants!

 

I am just about to take delivery of 2010 model lll and the 12 volt problem is a main concern, I will be keeping a battery jump pack with me all the time. I wonder too if this crappy battery can be replaced with a somewhat larger one, Does anyone have any information about a replacement other than Toyota... eg. Mtcy, boat, lawntractor, etc.

 

Optima Yellow top
There's info in PC It costs about the same as the OEM but is a much more solid battery.
Installation kit for installing Optima battery in 2000 - 2003, 2004 - 2009 & 2010 Prius

 

the dealers end up asking for more service than required generally.

 

If you do a search you will find others that have replaced the 12V with one of thier own choice. Some threads are very discriptive also.

 

My 2005 Prius which has given me no problems in the 5 years of ownership, just let me down this week. It didn't stall, but while in a drive-thru line for food, a long beep sounded and I looked up and there appeared to be 10 lights illuminated, including the triange with exclamation point, the main req, check engine, VSC, ABS, BRAKE PADS, and some other ones I don't even know what they are for. Was afraid to drive it but was only a mile from my work so got back there and called the dealership. They told me when the computer senses certain problems, it shuts the ABS, VSC, and other systems down and that I should be able to drive it to the dealer which was 3 or 4 miles away. Took it in and when they did the diagnosis, it was the main battery. Have only 55,000 miles on the car and fortunately that battery is warrantied for 8 years or 100,000 whichever occurs first. To replace that battery now is $3,500 with labor. The replacement cost has come down some but my fear is what to do in three more years, either trade or keep. Had planned on keeping this car as long as possible but now maybe I should rethink as the hybrid system warranty gets closer to running out. Most Prius owners 10 years out haven't had to replace either battery. The dealership tested my 12-volt battery and it test OK and (5 years old). I also don't drive long distances, but do drive the car daily. Have left the car on several occasions for two weeks while on vacation. When leaving the car for that long, I always disable the smart key system.

 

I am confused, isn't one free replacement on the HV battery enough? How many decades are you planning on keeping the car?

 

So if you've read through most of this or any of the many other 12V battery threads you will know to take that dealer battery check with a grain (or a full cup) of salt. Test it yourself: http://priuschat.com/forums/newbie-forum/73400-weird-stuff-happening-mpgs-dropping-test-battery.html
Or just dive in and get a new 12V battery anyway. Might save you a lot of hassle - even if it is fully covered under warranty.
I just find it hard to accept that your traction battery is failing BEFORE your 12V...

- D

 

In installed the Audio Force XPC550 Deep Cycle 12V battery in my new Prius - AND
because it is sealed and an AGM battery - it does not leak, corrode the terminals,
and does not need to be vented. Installed exactly like the Optima d51 instructions.
It had more reserve capacity and terminals than the OPTIMA.

I purchased mine at:
batteriesareus.com

 

Is this battery made in USA? I get the feeling from the look of it it is made in china. Not sure about the venting issue, aren't the Optima AGM but with vent? Looks like a really good option, if, for me anyway, the item is US made and the vent is not needed.

 

My 2008 Prius battery was just fine when I did not drive it for four weeks and 2 days. Plus I never heard that before.

 

Our dealer needs a SMART FUNCTION button, too. I had a problem with my '07 Prius battery. The car would start and run, but it would intermittently lose all it's memory except for the odometer. I stopped at the dealer, they checked the battery and said it was fine. As soon as I got home, it happened again. My car was in the shop one whole day and they could find nothing wrong. They asked to keep it the next day. Meanwhile, we had a death in the family and needed to leave the next morning for Ohio. This problem happened more than just a few times. We drove to Ohio, luckily with no problem. After the funeral, my son and my BF took the compartment apart. What do you think they found? The terminals on the battery were loose AND the tech left his tools in the spare tire well. Anyone have a SMART FUNCTION button they aren't using???

 

I have a 2007 with about 35,000 miles on it and probably drive it a bit less than you and have no problems as of yet. Being retired, I have plenty of time on my hands, and I would considering following up with Toyota. That just does not sound right.

Best

Hal

 

There are many different avenues you can take when buying a 12V battery. I bought an ordinary wet cell from batteries are us for $90.00 The terminals were the identical size, that's why I chose this battery. One can also buy a MC, Lawn equip, smaller deep cell. Almost anything works. It should be around 30Amps. A smaller battery MAY charge up better tho. If you are a DIY and electrically inclined you can go these routes. Some changes have to be made to accommodate any differences between battery and connections. The Purist on PC will warn of dire calamitous events should you not subscribe to the exact orig equip or the optima battery. But it is simply untrue. The biggest problem one has seems to be with the Prius Charging system, it appears to be current limiting, so never will you be able to hold a 13-14 Volt Charge, even on a new battery. Even on the OEM battery! I think this is the main reason for so many dead or weak battery problems.

 

On a 2005 Prius with just over 80,000 my wife had the red exclamation point go off while traveling in New Hampshire. Following the owner's manual, she had it towed to the nearest Toyota dealer. They said that the cause was the 12V utility battery. Their charge was $300 ($200 for the battery + $100 labor).

This seemed excessive to me, but they had us by the short ones. We had them replace the battery.

We also have a 2006 Prius, so when it gets to 75,000 I'm likely to just replace the battery myself, to try & stay ahead of the dealerships.

Any other thoughts? Suggestions?

 

elearnaid sells a kit to convert a D51 Optima Yellowtop to fit a Prius

Toyota Prius 12 Volt Auxiliary Battery with install kit for 2004 - 11

Optima themselves sell a custom made Prius battery for $200

Optima 12 Volt Performance Battery - Sealed Batteries by Optima

And there is the Battery Toyota sells.

You need a AGM, externally vented battery with odd posts, that limits your safe choices. (Many batteries would fit and work fine in the car, but not be safe for your passengers and you)

 

The local dealer quoted me $150 for battery + install. He said there wasn't a special sks battery, is this true? A good deal?

 

There is a real issue with the 12V battery. Batteries have been traditionally used to start a car. If it can start a car it is in reasonable condition. With the Prius the 12V battery does not have really high current loads. It only needs to provide 9.5V to start the computer (at a few amps). Once in Drive the HV battery charges the 12V one. I am a qualified Electronic Engineer, by the way, and I see this as a reckless process. If a 12V battery is allowed to deteriorate to the point where someone needs to jumpstart the 12V battery, the battery will be in such poor condition that it may well not provide a good enough 12V for all the safety equipment. (All the other ECUs) It is possible to check the 12V line voltage from the diagnostic screen if you know about it. It can be checked easily, in ACC,IGN and Drive. The 12V battery is guaranteed for 3 years, but I am yet to find the specification that the guarantee is written to. In my view the 12V battery on a Prius is a critical component and should be tested each service for degradation. It should be replaced if it cannot be guaranteed for another year.

 

I have a 2010. The dealer said that the battery will die after TEN DAYS of non-use. I said Wth! It is true. He showed me a service bulletin which showed how to pull the "short pin" in the fuse box if the car will not be driven for 10 days. Very Bad Engineering.

 

Where is that short pin?