Auxilliary Battery Life: Please POST if you have replaced yours

Since you are new to the site and have little credibility at this point. Some of us here are reluctant to participate in your survey.

Before some of us would give this information we would want to know.

1) Who you are.

2) What organization that you represent.

3) What the information will be used for.

4) Why you want the information.

5) Some type of verifyable identity so we can check out you credentials.
Phone number
Address
Wed site

Thanks in advance for supplying this essential information. You may not know this, but this site gets a lot of trolls. Before we feed the troll (so to speak) we like to make sure that this is a worthwild survey.

 

Hi. I replaced mine too at near the 4 year mark. I had left the car in our garage (with the dash button under the steering wheel disabled) while on an extended trip and when I got home in about 6 weeks the car wouldn't start. I trickle charged it and it came back seemingly ok. The next time I left on a similar trip, I disconnected the auxilliary battery under the hood at the special "Jump" terminal located in the fuse box. Then I learned a lot more about this battery that actually doesn't start the car, only powers several 12V items. I learned a lot at elearnaid dot com website, Prius Parts, and select the Yellow Top 12V battery - like you can actually test the auxilliary in place in the Prius. I failed the load test at about 10 VDC so I replaced the battery with an original type from a local dealer ($138.50) (I was very tempted by the Optiplex Yellow Top though [$165 plus kit]). Important Note: If the auxilliary battery is continuously trying to charge from the Nickel/Metal/Hydride it lowers gas mileage because that electricity is not available then for Hybrid use.

 

i agree w/ jayeeegee, however opted for the OPTIMA Yellow Top after reading the following from eLearnaid...

"The 12 volt battery is not used to crank the gasoline engine in the Prius but it does supply all the 12 volts circuitry which includes all of the computers in your car. If this battery fails, the computers will not start and the Prius will not start. A weak battery can also pull the 12 volts power down to a lower voltage. This can cause problems with all of the computers that control your car. (When I had a problem with my car the first thing the dealer insisted I do was replace the battery. The problem was caused by something else but the battery was weak.)

Since the 12 volt battery does not start the gasoline engine you can still use the car with a very weak battery. So much so that at least three Classic Prius users have told me that their Prius now gets better mileage with the new battery. One told me that getting a new battery restored his mileage back to the original mileage he was getting when the car was brand new and another told me that he is now getting better mileage then he did originally. Here is the third owner's comments: "All installed and working GREAT! My mileage has jumped amazingly (>10 mpg). Would have saved considerable amount of money by replacing earlier. Thanks again for being there."

So if you 12 volt battery is weak it could also be affecting your gas mileage because your Prius is wasting energy trying to recharge a battery that will not take a charge.


Another user had let the 12 volt battery degrade to a point that he had to turn the ignition on and off four or more times to start the car. He told me his gas engine would never shut down when he was driving.

In short, if your 12 volt battery is four or five years old we recommend you replace the battery. The normal battery life is four to five years."

12 Volt (12v) Toyota Prius Auxilary Battery for 2004, 2005, 2006, 2007, 2008 and 2009 with free shipping

 

Mine is 3.5 years old and I'm having problems with the discharge that occurs when charging the Hymotion pack. Right now I'm running a trickle charger as I charge the Hymotion pack, but I'm pretty sure my problems indicate that the battery is nearing the end of its life.

This site for the Optima yellow top battery lists some nice commonsense tests for checking your auxiliary battery. Look at the bottom of the page to see (e.g.) acceptable voltage drop when you turn on the headlights.

12 Volt (12v) Toyota Prius Auxilary Battery for 2004, 2005, 2006, 2007, 2008 and 2009 with free shipping


Also, the discussion of possible reduced mileage from a bad aux battery was new to me. The argument is that the car expends energy trying to charge your dying auxiliary battery. Not sure I buy it but it sounds plausible.

Finally, does anyone else find it odd that there appears to be only one off-the-shelf alternative to Toyota for the auxiliary battery? I understand that the battery is a little exotic, but these cars are going to need hundreds of thousands of battery replacements in the next few years. You'd think a few companies would have figured out a way to make a buck off that, when the alternative is spending $250 at the dealer.

 

Mfr Date Jan. 2004
Model Yr 2004
Mileage 40,000km(24,860miles)
Date Aux Bat Replaced not yet
City/State Yokohama, JAPAN
My aux battery seems fine, but my dealer checked it using a battery tester, then the guy told me the aux battery becomes weak and it won't die tomorrow, but it'll die in six months.
So, maybe, 5.5 years aux battery life.

Ken@Japan

 

I wasn't expecting the Spanish Inquisition but I'll share my information:

• 2003, NHW11, 115,000 miles
• Added water summer 2008
• Replaced auxiliary battery January, 10, 2009
• Replacement Odyssey PC925

Odyssey PC925 Specifications:

• 925 cranking amps for 5 seconds
• 870 cranking amps for 10 seconds
• 765 cranking amps for 20 seconds
• Short circuit current over 2400A
• 28 amp hours
• 50 minute reserve capacity with 25amp load
• Female brass terminal w/M6 SS bolt
• Length 6 15/32"
• Width 6 7/8"
• Height 4 7/8"
• Weighs 24 lbs
• Rugged Drycell sealed design
• Military grade
• Vibration resistant
• 60% more starting power
• Deep discharge reserve power
• 2 year storage life
• 8-12 year design life
• Can be mounted in any orientation (see link below)

http://www.odysseybatteries.com/battery/pc925l.htm

With a 1kW inverter with 1.2kW surge capability, I wanted a battery capable of providing surge for short intervals. With this battery, I would feel comfortable with an inverter with a 1.5kW surge but would stay within a sustained, 1kW inverter limit. The normal Prius inverter provides 1 kW before starting to drop voltage.

Since the PC925 rating of 28 Ahr is lower than the OEM reported values, I'm adding a $20, 1.5W solar tickle charger. This will handle any long-term power requirements and hopefully maximize the 12 VDC battery life.

Bob Wilson

 

96 posts, in my mind, does not make him new to the site, or am I missing something?

 

for one thing.. I would like the information. I have 175K on my car, with the original battery.. had it tested.. and it is weak.. but not dead..
the car is just 5 years old. (by MFG date) so.. I will probably replace it in the spring.

one other thing I would like to add to his specs..
Is if you have the SKS system or the regular key FOB.
I think I remember there being a beefed up battery in the prii that have the SKS system..

Scott

 

Battery manufactured 21 Feb 2004 and put in service 09 April 2004. Replaced 31 Jan 2009 at 35,000 miles with an Optima yellowtop from eLearnaid when the no-load voltage went to 12.4V (there were probably a few more months of life in it, but what th' heck).

The fob batteries fail when they get to about 2.7V. I moved the battery from my unused spare fob about six months ago when the battery in the primary fob died, but the old spare lasted only six months in service. So I will not buy another one for the spare unless I start using it.

 

+1

Since others w/ 2004's were starting to croak ~ we went ahead & got the yellowtop optima to replace the underpowered stock'er. Since then, I've accidently left the dome light on all night (2 or 3 times) to no issue. Much better.

 

Replacement Odyssey PC925

• 8-12 year design life

Bob Wilson
From odyssey web page
"Designed and built to last up to 3 times as long.
Thanks to rugged construction and AGM (Absorbed Glass Mat) design, ODYSSEYâ„¢ batteries have an 8-12 year design life and a 3-10 year service life. "
Thanks for your stepping out into some new territory with your purchase, something I'll probably do as well. The 8- 12 year spec caught my eye, maybe we should all be expecting a lot more from these newer style batteries. My 04 with 133k seems okay with it's original. I do check it's voltage sometimes when car is off with scanguage, 12.3-12.4. I probably should check it directly at the battery, I sure there is some voltage drop by the time it gets to my scanguage. A wikipedia chart states 12.24 as 50 % capacity and 12.45 as 75 % capacity, so.... guess it's something I am thinking about.

 

'04/4 years.

 

2008 with 31,000 miles.

Battery checked weak (not dead). Previous owner traveled frequently so car sat. Replaced with Optima Yellowtop, largely for peace of mind reasons. Having one of these 12v batteries go dead can be a much larger hassle than losing the 12v in a conventional vehicle and needing jump to get home.

 

I bought my Prius new in May 2007. I replaced the 12V battery with an Optima Yellowtop this morning. This was an act of preventative maintenance. I wasn't having any signs of trouble yet, but figured the battery was on the downside of its life and I wanted to be safe instead of sorry.

 

Mfr Date: Don't know - not near car.
Model Yr: 2007
Mileage: Guess 15k
Date Aux Bat Replaced: Jan 2008
City/State: So Cal.

I had foot surgery so I couldn't drive for 6 weeks or so.

During that time, the OEM battery died really good and hard - NO signs of life. (I suspect that the trunk light got left on...)

After that, the original battery wouldn't hold a charge at all.

Optima Yellow top in there since and nary a problem since.

 

Aarrrrggghhhh....Nobody expects the Spanish Inquisition, it's 2 main fears are Hummers, Opec, and the 12 volt Battery going to hell!!

I just replaced mine with a Yellowtop from eLearnaid, drove the 4Runner over and picked one up. They are just a piece up the freeway from me, Nice Folks!!! Great Battey!!!
OEM battery had 21k miles. I was on Vacation, the car sat for 3 weeks, the battery got sucked down to 3 volts twice.......NOT GOOD EGON, I now have put big honkin high amp capable on / off kill switch to kill the "Extra Acessories" that tend to suck all battey lifeforms to death if left to do so!!! I.E. Subwoofer amp, 2way radio! Will also have to remember to kill SKS!
In 3 Vacation weeks, I was working so much on putting in my new front yard, I did not need to drive it. I was using the 4Runner for big dirty things....that don't fit or belong in a Prius!
Yellowtop, Good Battey +1