12 volt 12v Battery chargers with repair or recondition mode

Discussion in 'Gen 3 Prius Technical Discussion' started by StephenFromCT, Nov 4, 2019.

  1. StephenFromCT

    StephenFromCT Junior Member

    Joined:
    Jul 17, 2019
    41
    11
    0
    Location:
    Connecticut
    Vehicle:
    2013 Prius
    Model:
    ----USA----
    Hello all,

    I do not understand the chemistry which explains why an auxillary 12 volt battery which is deeply drained (and therefore needs to be jumped started) has a very short life span. In other words, it is not the jump starting which damages the battery, but the initial deep draining.

    I would like to buy a battery charger for the 12 volt battery. Some chargers, which are more expensive, have a repair or recondition mode which they claim can increase the storage capacity of old or restore the ability of heavily sulfated batteries to store a charge.

    Does anyone have experience recharging drained Prius 12 volt batteries using a charger with this feature? If the Prius 12 volt battery is drained, then will using a charger with a repair or recondition mode extend the useful life of the 12 volt battery? Another feature which I like is overcharge protection.

    Two companies which sell these types of charger are Noco and Smartech.

    Thanks for your thoughts!
     
  2. StarCaller

    StarCaller Senior Member

    Joined:
    Feb 15, 2014
    1,142
    631
    0
    Location:
    Cedar Crest, NM, USA
    Vehicle:
    2014 Prius
    Model:
    Two
  3. Iketorz

    Iketorz Junior Member

    Joined:
    Oct 7, 2018
    33
    11
    0
    Location:
    Florida
    Vehicle:
    2010 Prius
    Model:
    IV
    I have experience using an oddball eBay cheap knockoff pulse charger (“Foxsur” brand, whatever that is) and it’s fixed some batteries but not others. In my experience a lot of batteries fail just from the jarring of being in a vehicle causing internal connection failures. If it’s got that, no amount of pulse charging will save it. If it really just got seriously discharged, I’ve read about leaving the battery on there in pulse mode for weeks at a time and seeing if it fixes. Be sure to monitor the battery temp doesn’t get really high while this is going on. With some off my batteries it got scary hot. I aborted the experiment when that would happen.
     
  4. ASRDogman

    ASRDogman Senior Member

    Joined:
    May 29, 2018
    3,811
    2,268
    0
    Location:
    Florida
    Vehicle:
    2010 Prius
    Model:
    Two
    A regular battery is not designed to be drained. A marine battery is and can handle it.
    I guess it is how they make it, and what they use.
     
  5. Nor'easter

    Nor'easter Member

    Joined:
    Nov 16, 2019
    151
    91
    0
    Location:
    New Hampshire
    Vehicle:
    2010 Prius
    Model:
    II
    I have a Pulsetech Xtreme charger that works well on sulfated batteries. I was terribly skeptical of claims. But when I inadvertently killed a 6 month old auto battery (dome light left on during Winter storage for about 8 weeks) and could not charge at all with my old school charger (3 days on charge, no action), I bought the Pulsetech (with 30 days satisfaction guarantee, and all expectation of sending it back). It worked great. Battery began to charge over the course of a few days and finally after 5 weeks it had been restored to as new in terms of performance and measured voltage & specific gravity. So the technology definitely works... but only if sulfation is your problem. Batteries have other failure modes, of course.

    So I bought a 2010 Prius with 98K in November. 12V battery is original (May 2010 date code iirc) and definitely ready for replacement. Hasn't failed to start the car, but the brake pump was clearly running slow and labored before starting the car, measured voltage at battery < 12 V with all loads switched off.

    About ten days ago, I put a charging pigtail on the 12V battery and I've put the pulsetech charger on it whenever the car is home. Let's say 12 hours a day average for ten days. One can leave the charger connected to the battery continuously and plug the charger in to AC when convenient. The battery is responding. I didn't bother putting the charger on last night (better things to do :)) and I checked the 12V battery this morning (well, maybe early afternoon, Christmas don't ya know) and It showed 12.25V, all loads off. The brake pump runs much better now. After the brake pump run, the 12V battery still shows better than 12.2V. It will be interesting to see how much capacity can be restored.
     
  6. Mendel Leisk

    Mendel Leisk Sand Pounder

    Joined:
    Oct 17, 2010
    46,021
    32,861
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    My CTEK 4.3 has a recondition option. That's about all I know though, haven't really needed it. I did try it at least once that I can recall. You can download pdf of the owner's manual, see how they describe it.
     
  7. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    95,324
    43,213
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    there are youtube videos
     
  8. Leadfoot J. McCoalroller

    Leadfoot J. McCoalroller Senior Member

    Joined:
    May 12, 2018
    4,459
    4,403
    1
    Location:
    Pennsylvania
    Vehicle:
    2018 Prius c
    Model:
    Two
    You already know that battery is toast. While you can gain some interesting data points but it's also a bit of a risk particularly going into winter.

    Just make sure the knowledge you're gaining is actually worth the risk. 12.25V @ all loads off is still quite low.

    I'd go buy the new battery, top it up on the bench, and leave it in the back of the car with a 10mm wrench. Then continue the experiment knowing you have a get-out-of-jail card already on board.
     
    Johnny Cakes and Ed Beaty like this.
  9. ChapmanF

    ChapmanF Senior Member

    Joined:
    Mar 30, 2008
    15,206
    10,582
    0
    Location:
    Indiana, USA
    Vehicle:
    2010 Prius
    Model:
    IV
    My understanding has been that it isn't the deep discharge per se, but some of what can happen next:

    • if deeply drained and allowed to sit that way a long time, the plates can grow sulfate crystals
    • deep discharge raises the electrolyte's freezing point closer to that of plain water, so if left that way in very cold weather, freezing damage can occur
    • most car charging systems aren't designed to charge a battery at a slow controlled rate, and will violently dump current into a very low-charge battery as soon as the engine has started (as is also happening during the jump start while racing the donor engine). That's where a lot of damage to the battery is done, and can be avoided by just swapping in a charged battery and taking the dead one to a nice controlled bench charger.

    The first couple Prius generations had a fairly low charge voltage, and probably weren't likely to damage the discharged battery during recharging; the flip side of that coin was needing to leave the car in READY for at least ten solid hours to fully recharge the battery. Gen 3 boosted the charge voltage, and AHetaFan measured its charge current reaching 60 or 70 amps if the battery is discharged enough ... but Gen 3 also has a temperature sensor above the battery, so maybe that helps.

    Prius batteries are built more like deep-cycle batteries than like starting batteries, because they don't need to start anything. That makes the situation better than it could be.
     
  10. Nor'easter

    Nor'easter Member

    Joined:
    Nov 16, 2019
    151
    91
    0
    Location:
    New Hampshire
    Vehicle:
    2010 Prius
    Model:
    II
    Another data point... after charging another 24 hours, I disconnected the charger, ran the brake pump, let the battery recover for a minute or so, measured 12.35V.
     
    bisco likes this.
  11. Nor'easter

    Nor'easter Member

    Joined:
    Nov 16, 2019
    151
    91
    0
    Location:
    New Hampshire
    Vehicle:
    2010 Prius
    Model:
    II
    The pulsetech charger has been on the car about 70% of the time since my last update. The car was driven 2 - 3 hours yesterday, parked overnight, charger left OFF. 8 hours later, I popped the hatch and checked the 12V battery, 12.64V. After running the brake pump and recovering for a minute or so, 12.45. After another half hour resting, it measures 12.63. Ambient temp is right around freezing.

    That's performance I'd be satisfied with in a 3 - 4 year old battery (see post #5, this one is almost ten years old). I'm going to score this one as a win for life extension.
     
    Mendel Leisk likes this.
  12. AzWxGuy

    AzWxGuy Weather Guy

    Joined:
    May 22, 2011
    842
    412
    0
    Location:
    Tucson, AZ
    Vehicle:
    2021 Prius
    Model:
    Limited
    I'll throw in for anything in the Optimate line I suppose. Based on my experience with an Optimate 5, I think their prediction of a 400% improvement in battery life is pretty close. I started using it in my 2008 and got an extra year or so (5 years) out of the OEM battery, and then moved it to my 2011 and got 8 years on the OEM battery. This device will also tell you if your battery is toast.
     
Loading...