NOCO battery tender ?

Discussion in 'Fred's House of Pancakes' started by cyberpriusII, Sep 17, 2025 at 10:56 PM.

  1. cyberpriusII

    cyberpriusII Maybe it was the roses

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    I bought one of the small Noco 12 volt battery tenders awhile back when I was not able to drive. Did not end up using it as it always seemed someone else was using my car...

    Wanted to hook it up today to my Subaru Outback and saw that there are various settings based on if the batt is just an old school 12v, AGM, extra flooded, etal.

    The factory OEM battery just has CCA on it and a part number. Extensive Googling got me nowhere except that some claim it is flooded. Some say regular and some say AGM. Subaru parts lists I found are no help.

    I could call the dealer, but I think that is about a 50/50 chance of a correct answer.

    So, if I hook it up as just a regular 12V will the world end?
    kris
     
  2. Trollbait

    Trollbait It's a D&D thing

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    The lack of such basic info on the battery seems common. It is likely a maintenance free flooded.

    Charging an AGM with flooded settings could lead a shorter life for the AGM. Sealed batteries like AGM, gel, and maintenance free don't have a way of replacing water from off gassing. Their charge profiles are intended to reduce that off gassing.

    The maintenance or float charge difference between the types likely won't be an issue. The amperage draw for a full battery will be low. I suspect any potential harm is less than letting the battery sit for extended periods without a maintainer.

    Not going to apply to your maintainer, but my Outback manual says not to charge the 12V at over 10amps.
     
  3. Mendel Leisk

    Mendel Leisk MMX GEN III

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    My (very limited) understanding, basically from reading in between the lines in my CTEK 4.3 manual, is that the only difference is for certain* AGM's only, the "snowflake" setting is recommended. It's for extreme cold weather, uses slightly higher charging voltage.

    FWIW, I installed a Optima Yellow Top battery, in September of 2015. With our usage so sporadic, I've had it on the charger more than off, and IIRC for the first few years I didn't use the snowflake setting. It's still going strong.

    * Pretty sure I saw the expression "spiral-wound" somewhere, like the 6-pack style Optimas, but not finding it at the moment

    upload_2025-9-18_10-56-48.png
     
    #3 Mendel Leisk, Sep 18, 2025 at 1:52 PM
    Last edited: Sep 18, 2025 at 2:01 PM
  4. cyberpriusII

    cyberpriusII Maybe it was the roses

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    Hey, all:

    Thanks for helping bounce the idea around.

    I needed to clean the Outback as I have to take a passel of people around this weekend. Apparently not everyone enjoys being covered in canine fur and for some reason they believe they ought to be able to see out windows without doggie slobber covering the glass.

    Anyway, the woefully underpowered Outback battery tends to die if I leave the hatch and doors open while cleaning. This time I just worked turbo mode and did half the cleaning. I then jumped in the car and ran some errands, recharging the battery and finished cleaning when I arrived back home at 8 p.m. We will see if it starts in the morning. LOL!
    kris
     
  5. T1 Terry

    T1 Terry Active Member

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    The AGM charging setting won't harm a flooded cell battery, but the flooded cell setting could damage an AGM battery .... that help at all?

    T1 Terry
     
  6. Mendel Leisk

    Mendel Leisk MMX GEN III

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    My CTEK manual says it’s setting for “certain” AGM batteries is slightly higher charging voltage. I’d take that to mean the regular charging parameters are safe for all, albeit under-performing for those AGM batteries.

    I’m an electrical dummkopf though…
     
    #6 Mendel Leisk, Sep 19, 2025 at 9:47 AM
    Last edited: Sep 19, 2025 at 10:08 AM