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GM diode install

Discussion in '2.5 Gen Tundras (2014-2021)' started by shawn474, Nov 27, 2023.

  1. Nov 27, 2023 at 7:10 PM
    #1
    shawn474

    shawn474 [OP] Lego connoisseur

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    I have an optima yellow top for the last two years. It I completely forgot that I had ordered the GM diode to optimize awhile ago and just found it in the garage.

    I am a little gun shy about installing it especially since the battery has been performing fine since it was installed. But if the diode can extend my battery life I would like to install it.

    So i will ask the group;
    1. Is it with it worth it to install?
    2. Is it simple plug and play? If so where and how does it install?

    Thanks in advance!
     
  2. Nov 27, 2023 at 8:20 PM
    #2
    Jim LE 1301

    Jim LE 1301 Camaro Lover, SSEM # 11,TTC#179

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  3. Nov 28, 2023 at 11:04 AM
    #3
    Cruzer

    Cruzer Wheeling Full Size

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    Since it's an AGM and the Tundra alternator does not provide enough voltage to fully charge the AGM, your battery is dying a slow death.
     
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  4. Nov 28, 2023 at 11:46 AM
    #4
    blackoutt

    blackoutt YEAH BUDDY!

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    Yes. Shave the sides down and fit it into the ALT-S fuse spot under the hood. Agreed with Cruzer. Yes your battery is "working fine" until it's not. Your AGM needs more voltage, the damage might already be done.
     
  5. Nov 28, 2023 at 11:48 AM
    #5
    shawn474

    shawn474 [OP] Lego connoisseur

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    OK I will install it and see what happens. Hopefully it allows for it to charge effectively. I completely forgot I had it and wouldn't have ever remembered if I didn't open a drawer in the garage and see it. Do I need to simply install the fuse or build the fuse tap contraption linked above?
     
  6. Nov 28, 2023 at 11:57 AM
    #6
    MadMaxCanon

    MadMaxCanon New Member

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    Too many, but not enough....
    you can just leave the stock fuse and put your AGM on a trickle charger once in a while if you park indoors.
     
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  7. Nov 28, 2023 at 12:04 PM
    #7
    shawn474

    shawn474 [OP] Lego connoisseur

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    It is my daily driver and parked outdoors. I do not have the ability to trickle charge it.
     
  8. Nov 28, 2023 at 12:16 PM
    #8
    HulkSmurf14

    HulkSmurf14 ...Weighted Average...

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    Tastefully enhanced...
    You will visually see the increase in voltage on your factory voltage gauge... it's worth doing!
     
  9. Nov 28, 2023 at 12:19 PM
    #9
    shawn474

    shawn474 [OP] Lego connoisseur

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    Just to confirm, I do have to use the fuse tap creation linked above - not simply plug in the new fuse?
     
  10. Nov 28, 2023 at 12:36 PM
    #10
    Black

    Black Raised Hands Surround Us. 3 Nails To Protect Us

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    Have had AGM batteries in 4 vehicles now. 2 Toyotas, a GM, and a Ford never bothered with a diode or voltage booster.
    Never had an issue.
    1 Napa Legend and 3 X2 Power batteries. When I emailed the folks at X2 Power 3 years or so ago about this they said it is not needed.
    It is also mentioned no where on their website.
    Being they give a 48 month full replacement if the voltage boost was necessary for proper charging one would think they would mention it.
    But it is nowhere that I can find.
     
  11. Nov 28, 2023 at 2:19 PM
    #11
    MadMaxCanon

    MadMaxCanon New Member

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    Too many, but not enough....
    Building on the above post, you can get a AGM from costco and they will warranty it if it takes a dump early.
     
  12. Nov 28, 2023 at 7:29 PM
    #12
    pvn.beluga

    pvn.beluga New Member

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    Yeah, it is. I installed mine when I picked up the X2 power group 34 from B+B. Make sure you put it in the right way - and like others said, you gotta shave it down a bit.

    I used zip tie cutters to trim it down a bit to fit into the slot.
     
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  13. Nov 29, 2023 at 4:06 AM
    #13
    pursuit2550

    pursuit2550 New Member

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    Interesting read from Interstate Battery. Seems higher volts is what kills a AGM battery. And like you said, even X2 Power didn't say anything about a diode. Sometimes it's better to go straight to the manuf who built it than to ask on the Internet for advice.
     
  14. Nov 29, 2023 at 4:19 AM
    #14
    Dawoofles

    Dawoofles New Member

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    It’s super easy. Get a little orbital sander tip and shave the ends down. Instant 14.4V
     
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  15. Nov 29, 2023 at 4:21 AM
    #15
    windblown101

    windblown101 New Member

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    Some awesome stuff sprouts up from the internet "collective"... but it can be tricky separating the wheat from the chaff. ;)
     
  16. Nov 29, 2023 at 3:53 PM
    #16
    shawn474

    shawn474 [OP] Lego connoisseur

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    Ok so I think I have this correct but checking for confirmation. @BiggHertz is this correct? IMG_0006.jpg
    IMG_0005.jpg

    IMG_0004.jpg
     
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  17. Nov 29, 2023 at 3:54 PM
    #17
    HulkSmurf14

    HulkSmurf14 ...Weighted Average...

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    SEND IT!!
     
  18. Nov 30, 2023 at 7:53 AM
    #18
    CaptRatBoy

    CaptRatBoy New Member

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    Somewhere around 2500' Western Blue Ridge, NC
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    Here's the "best" solution, not the cheapest, to undercharging your AGM batteries. The GM diode mod does get the job done but ....
    https://voltageboosterpro.com/
    On the low switch setting I've averaged about. a 0.05-.06 volt increase on the high setting usually pick 1.0-1.2 volts.
    Check you battery going in and after a couple hundred miles of driving.
    Best
     
  19. Nov 30, 2023 at 12:48 PM
    #19
    ronrich

    ronrich New Member

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    This is an interesting idea. Quite frankly I didn't know this was even an issue until reading this post. My last AGM lasted just shy of 4 yrs. Isn't that pretty typical of battery life? I just checked my new AGM battery and with the vehicle running it reads 13.8 V and off 12.6 V. Curious what your battery reads when the vehicle is not running or as fully charged.
     
  20. Dec 1, 2023 at 6:37 AM
    #20
    CaptRatBoy

    CaptRatBoy New Member

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    ronrich....
    Think it just depends upon how big an obsessive nut case one tends to be. Ball park rule I'll just change out all battery's in the system about every four years because our vehicle's "have" to start and run. We've got other's depending on us. For a stock alternator your numbers 13.8 and 12.6 are in the ball park. Our truck's with the optional 180 alt., comes with the Tow Package, read about the same in stock configuration. Add the modification, Voltage Booster PRO, just brings them up a rousing additional half to 14.4-6 volts. Is it worth it? or even necessary? I don't know. I just look at it as an additional insurance policy.
     
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  21. Dec 1, 2023 at 6:43 AM
    #21
    shawn474

    shawn474 [OP] Lego connoisseur

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    That's kind of where I am at too.....if the $90 invested even brings a bit of performance over the life of the battery to extend it, I see it as a small investment for peace of mind especially with how long I plan to own the truck. I ended up buying the voltagePro booster so if anyone would like the diode fuse tap that I built above for free, I offer it up as Karma in the spirit of the holiday. Just PM me your address
     
  22. Dec 1, 2023 at 6:43 AM
    #22
    Johnsonman

    Johnsonman New Member

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    What i read is AGM will not tolerate high voltages for charging, that damages them. On the other hand they Want high amperage to charge, they can take far more current than non AGM, hence Faster charging but not with voltages over 14.5.

    Here's an article from Interstate Battery: https://www.interstatebatteries.com/blog/how-to-charge-an-agm-battery
     
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  23. Dec 1, 2023 at 6:45 AM
    #23
    texasrho83

    texasrho83 Old Member

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    I have used the Aussie-made option, and am now on the GM diode. I still have to hook my trickle charger up once a month.
     
  24. Dec 1, 2023 at 6:57 AM
    #24
    coTony

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    I have one of those jiggamabobs in my garage from my Tundra. It worked fine but took it out for something I was doing and never put it back in
     
  25. Dec 1, 2023 at 6:59 AM
    #25
    Ghost Rider

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    Honestly, I am using GM diode and trickle charge every other month or so (if I remember) but I really don't know what my voltage should read.....:(
     
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  26. Dec 1, 2023 at 7:00 AM
    #26
    coTony

    coTony member since sept, 2017 and a BUNCH of messages

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    My battery has that information on top of it, check yours out
     
  27. Dec 1, 2023 at 7:11 AM
    #27
    texasrho83

    texasrho83 Old Member

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    14.0+ while you're running around and 12.0+ with your engine shut off is normal specs from what I've read
     
  28. Dec 1, 2023 at 7:20 AM
    #28
    Ghost Rider

    Ghost Rider Mods wouldn't be an issue if money wasn't.

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    My morning startups have been 14.5V and would drop to around 13.8V-14V while driving. Not able to read bluetooth transmission when engine off.....
     
  29. Dec 1, 2023 at 7:23 AM
    #29
    texasrho83

    texasrho83 Old Member

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    A multimeter or charger w/diagnostic capabilities can tell you voltage when you're shut off. With your running numbers being what they are, you're probably golden
     
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  30. Dec 1, 2023 at 8:08 AM
    #30
    shawn474

    shawn474 [OP] Lego connoisseur

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    I installed an alpine head unit that connects to the OBDII port and reads voltage; while driving around yesterday I checked and it was reading 12.9-13.1 voltage. Is that normal?
     

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