Warning signs the 12V battery is on life support

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by working1, Feb 22, 2016.

  1. working1

    working1 Active Member

    Joined:
    Apr 1, 2013
    120
    108
    0
    Vehicle:
    2012 Prius
    Model:
    Two
    • Noticeable hesitation when ICE starts up while driving

    • ICE does not shut off when parked and idling

    • Check engine light with code P2200, NOx Sensor Circ Bank1

    • Heavy vibration when ICE starts up any time

    • The noise of the vacuum pump preparing the brakes before starting is very different. It becomes very long and drawn out. Almost like a plea for help.
    I encountered the first issue about 2000 miles before replacing the 12V battery. The original battery would always start up in ready mode, but, I’m worried what else was impacted by a battery at less than 100%. My impression is certain sensors/electrical components depend on a healthy battery otherwise it starts sending bad info to the computer which over and/or under compensates.

    The new battery (yellow top) solved all the problems above. I wish Toyota would have a more intelligent way of flagging a 12V battery issue. It seems way more important to know this on a hybrid than a non-hybrid.
     
  2. sillylilwabbit

    sillylilwabbit Active Member

    Joined:
    Jul 16, 2015
    405
    118
    0
    Location:
    Los Angeles
    Vehicle:
    2014 Prius Plug-in
    Model:
    Plug-in Base
    How old is your battery when you replaced it?


    iPhone ?
     
  3. working1

    working1 Active Member

    Joined:
    Apr 1, 2013
    120
    108
    0
    Vehicle:
    2012 Prius
    Model:
    Two
    Just over 4 years. Toyota OEM battery, manufacture date 01/2012. Car was purchased 04/2012.
    Just over 4 years. Toyota OEM battery, manufacture date 01/2012. Car was purchased 04/2012.
     
  4. Former Member 68813

    Former Member 68813 Senior Member

    Joined:
    Oct 3, 2010
    3,524
    980
    8
    Location:
    US
    Vehicle:
    Other Hybrid
    Model:
    N/A
    very interesting. the last item totally makes sense. the first 4 not really, but i believe you. I totally agree, there should be some warning for the 12V battery. there is one for the 3V one!
     
  5. Mendel Leisk

    Mendel Leisk Patron saint of newly poured sidewalks

    Joined:
    Oct 17, 2010
    50,004
    35,568
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    Pick up a multimeter and maybe an electronic load tester, no more mystery.

    image.jpeg
     
    padroo likes this.
  6. Rebound

    Rebound Senior Member

    Joined:
    Mar 11, 2010
    3,947
    2,584
    0
    Location:
    Portland, OR
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    What voltage should a Voltmeter display for a healthy battery?
    I just checked mine, and it's a steady 12.75V after four years and 85K miles. I checked from the jump start plug, with the car fully off.
     
    #6 Rebound, Feb 23, 2016
    Last edited: Feb 23, 2016
  7. qdllc

    qdllc Senior Member

    Joined:
    Aug 25, 2013
    1,328
    384
    0
    Vehicle:
    2013 Prius
    Model:
    Two
    That's problematic. A healthy battery not being charged reads at or above 12v, but being under 12v (by a little) isn't odd.

    The problem is that the Prius uses the big battery once things start up. This conceals the strength of the 12v battery.

    In a normal vehicle, the sound of the starter straining or a long crank cycle to start is a sign of a weak battery. Likewise, if your headlights dim when the engine drops to idle, that means the 12v is weak.

    Does the Prius headlamps work with the car off? That might be a way to see if the 12v is weak as I'd expect anything operating while the car is in OFF mode is running off the 12v battery.
     
  8. Mendel Leisk

    Mendel Leisk Patron saint of newly poured sidewalks

    Joined:
    Oct 17, 2010
    50,004
    35,568
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    That's very good. There's a chart of voltage here:

    The 12volt Side of Life (Part 1)

    Only thing, a battery showing decent voltage can still be getting on, somewhat weakened. The load testers (like the Solar BA5) test Cranking Amps electronically, are good for this. Most battery retailers will have a similar but professional level tester.

    One other thing, a freshly recharged battery will show voltage higher than reality for a day or so, best to drive it a bit, let it rest overnight, then test.
     
  9. working1

    working1 Active Member

    Joined:
    Apr 1, 2013
    120
    108
    0
    Vehicle:
    2012 Prius
    Model:
    Two
    Headlights worked with car in OFF mode. I turned them on for 30 seconds and used a voltmeter which showed 12.66 volts.

    The voltmeter reading is not useful, in my opinion, for a hybrid. References typically show what to use for a non-hybrid. There is something else going on with a hybrid 12V battery that impacts performance, such as ICE hesitation, yet good enough to start the car in ready mode.

    How difficult would it be to add software code to monitor the system for a failing 12V battery? This could include monitoring sensors and components that need a healthy 12V battery to function. Seems like all the software engineering went into the main battery pack and nobody thought about the 12V.
     
  10. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    101,172
    45,873
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    battery should last 7 or 8 years, unless you've drained it, or don't drive much.
     
  11. working1

    working1 Active Member

    Joined:
    Apr 1, 2013
    120
    108
    0
    Vehicle:
    2012 Prius
    Model:
    Two
    84 to 96 month battery life expectancy seems a bit long. Interstate Batteries has a graphic that estimates battery life based on climate which seems a little more logical.

    batterylife-map.jpg
     
  12. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    101,172
    45,873
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    i don't think interstate makes a prius battery?

    but anywho, we don't know your location of course. but i think interstate likes selling batteries. since my batteries have always lasted 8-10 years, in all my vehicles, i can only assume the ones not lasting as long have been abused in some way. but i could be wrong.
     
  13. FroggyTaco

    FroggyTaco Member

    Joined:
    Dec 4, 2011
    211
    58
    3
    Location:
    Paso Robles, Ca
    Vehicle:
    2013 Prius
    Model:
    Two
    bisco likes this.
  14. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    101,172
    45,873
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    thanks! looks just like an optima.
     
  15. Mendel Leisk

    Mendel Leisk Patron saint of newly poured sidewalks

    Joined:
    Oct 17, 2010
    50,004
    35,568
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    Click on the pic in the link and even more so:

    Capture.JPG
    For me the "view Canadian pricing" link is not much help: leads to a page with parts numbers, none of which correlate to the above. SaskBattery worked for me up here, free shipping and they charge GST only, no PST.

    GST = Goods and Services Tax
    PST = Provincial Sales Tax

    (both are 6% in BC at least)

    BC = British Columbia
     
    #15 Mendel Leisk, Feb 27, 2016
    Last edited: Feb 27, 2016
  16. Chris @PNW

    Chris @PNW New Member

    Joined:
    Dec 25, 2017
    5
    0
    0
    Location:
    Seattle, WA
    Vehicle:
    2012 Prius c
    Model:
    Four
    At 4.5 years & 18,000 miles, my 2012 Prius c could not be started. The first Geico roadside assistance guy gave up on jumping my car and left me stranded (no kidding, he left in a nasty huff after trying to pull off the cover under the back seat). Another guy came out, and we still couldn't get it started; but he had a tow truck and took me to my dealer. My dealer replaced the 12V battery for $276 (plus $125 labor). 9 months later (and only 1,000 extra miles), my car again won't start (it's obviously the battery). I've now moved clear across the country, so I'm not able to return to the dealer who replaced my 12V battery. It's most unpleasant when the battery fails unexpectedly (my problems were not the result of leaving lights on), because a jump won't work. I can't believe I've had this twice in a year, I now see the great risk in having a hybrid car when they're still not well understood.
     
  17. FuelMiser

    FuelMiser Senior Member

    Joined:
    Jun 29, 2008
    1,118
    786
    0
    Location:
    Monument, CO
    Vehicle:
    2016 Prius
    Model:
    Touring
    I wouldn't blame this on the battery, necessarily. You said the first/original battery lasted 54 months and 18,000 miles (333 miles/month) and next one 9 months and 1,000 miles (111 miles month). These are extremely low numbers, in my experience. I think you need to put your 12V on a maintainer/tender based on your low miles driven.
     
    working1 likes this.
  18. cipsaz187

    cipsaz187 Member

    Joined:
    Feb 19, 2014
    142
    36
    0
    Vehicle:
    2012 Prius
    Model:
    Four
    Ok, so my battery will be six years old soon. I sometimes put in on the charger, but haven't done that in months..

    It's has been below 0 F in the past two weeks. The car is being driven every day, and sometimes every second. I've been unable to check the battery level because the damn hood is frozen.
    The car starts just fine, but I know the battery is low on charge because it runs rough for some 40 minutes until it gets charged and then goes to EV and smoothens out. It runs high RPM even at the stop light and its annoying. Once the battery has enough juice, the car runs as its suppose to.
     
  19. padroo

    padroo Senior Member

    Joined:
    Jan 11, 2008
    2,763
    2,246
    13
    Location:
    Chesterton, Indiana Another third world country.
    Vehicle:
    2016 Prius
    Model:
    Four
    One problem with the Prius battery is it isn't a common battery. To my knowledge you can't get one from Walmart yet. At the first sign of strangeness on my 2008 I ordered a yellow top Optima on eBay and replaced it. The Optima was a lot cheaper than the OEM Toyota battery, and it was still fine at the ten year mark when I traded it in in November. The Optima was at that time the only manufacturer that had the place for the hose that vents the battery. I don't know if anyone else has made a replacement battery yet for the Gen 2.
    At that time the Optima was a lot cheaper that the OEM Toyota, I just checked and it is not anymore.
     
  20. ChapmanF

    ChapmanF Senior Member

    Joined:
    Mar 30, 2008
    19,412
    12,960
    0
    Location:
    Indiana, USA
    Vehicle:
    2010 Prius
    Model:
    IV
    Funny, I've noticed this particular behavior in my 2010 the last (very cold) couple of days.

    You're doing a huge amount of speculation there, though, about why the car's control software is behaving that particular way. (Necessary disclaimer: the software is Toyota proprietary, I've never read it, but then neither have most other PriusChatters who write very positively about why it does a particular thing. The best information most of us have is what the manuals tell about what it does and why.)

    There are some things we do know, though. First off (because this thread is about the 12 volt battery), it's worth remembering that the condition of that battery, whatever it is, becomes immaterial to the rest of the car as soon as the READY light comes on. The 12 volt bus, at that point, becomes powered by the car's DC/DC converter, and will have a stable voltage right around 13.8 to the low 14s. The only way a bad 12 volt battery could affect anything else voltage-sensitive in the car after that point would be if it is shorted, and drawing so much current that it loads down the DC/DC converter output. That's worth talking about as a possible scenario, even if only to remember how easy it would be to detect: watch the system voltage when in READY. I do (it's one of the values on my ScanGauge), and my voltage never wavers from the high-13-to-low-14 normal output range, so at least in my case, loading by a super-bad 12 volt battery is not among the possible explanations.

    There is another battery in the car, though, and I suspect it might play a part in the cold-weather high revs we're seeing. The traction battery is monitored for temperature, and the car treats it extra delicately whenever the temperature is too high or too low. In Gen 1, there was even a turtle-shaped light on the dash to show you when that was happening. Later gens have no turtle light, but they still watch the battery temperature.

    In my driving the last couple of days, I've noticed both: (a) more engine noise when moving off from a stop (because the engine is doing more of the work than usual, confirmed by the ScanGauge showing lower current from the traction battery than would be normal in milder weather), and (b) higher revving when slowing into a stop, lasting for some moments after stopping before coming back down to a normal idle speed. It sounds a lot like the B-mode use of the engine to burn off excess regen energy that the battery controller doesn't want to shove into the battery, and this is at least supported (I don't say confirmed) by the ScanGauge showing no more than 20 or 25 amps into the battery, during a deceleration/stop that would normally show 60 to 80. And this strange behavior happens less, further into a longer drive, which could well be a consequence, not of the battery's state of charge, but of it reaching a more suitable temperature.

    I have not set one of the ScanGauge displays to show traction battery temperature, which would be a natural way to test whether that possible explanation has legs. But there is enough information already to strongly suggest looking in other directions than the 12 volt battery.

    -Chap
     
    JStrenk and CR94 like this.
Loading...