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Agm battery charging..

Discussion in '2.5 Gen Tundras (2014-2021)' started by Mrf1987, Nov 2, 2021.

  1. Feb 20, 2024 at 2:05 PM
    #211
    Saltyhero13

    Saltyhero13 Throbbing Member

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    Fuel delete mod Cup holder upgrade
    There is a ~.2V drop across the diode to keep it open. The ECU sees the drop and increases the output of the alternator by the same amount.
     
    seahaul[QUOTED] likes this.
  2. Feb 20, 2024 at 2:35 PM
    #212
    bfunke

    bfunke Tundra Curmudgeon

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    An alternator produces current flowing through the spinning field coil (the rotor) which creates high frequency AC power in the stator (stationary) coils. This is rectified to DC by a series of diodes, which are mounted behind the regulator and cover. Control schemes vary, but all alternators regulate output voltage by varying current in the field coil, which is fed via 2 brushes and the slip rings. The current is varied to maintain a specific output voltage. On 12V systems this varies from 13.3-14.7 volts depending on vehicle type and temperature. The regulator the alternator compares the voltage between B+ (alternator output) and ground to its reference voltage. The current in the field is adjusted accordingly.

    By adding a diode to the B+ side of the regulator, we fool the regulator into thinking the main bus (B+) voltage is lower than reality. The regulator will then adjust the output voltage so that it is equal to its internal setpoint +Vfwd (usually about 0.5V) of the diode.

    Hope that explains it.
     
  3. Feb 20, 2024 at 2:51 PM
    #213
    seahaul

    seahaul New Member

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    thanks for the replies, I understood the voltage looked lower because of the diode but didn't understand why. I did not understand why a diode would change voltage until now :). thanks again!!
     
  4. Feb 22, 2024 at 8:17 AM
    #214
    Rodtheviking

    Rodtheviking New Member

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    I used the diode for a couple of years without any issues but switched to the voltage booster pro for a little peace of mind.

    https://voltageboosterpro.com/
     
  5. Feb 22, 2024 at 8:39 AM
    #215
    Saltyhero13

    Saltyhero13 Throbbing Member

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    That still use diodes but has an inline fuse.
     
  6. Feb 22, 2024 at 9:04 AM
    #216
    Rodtheviking

    Rodtheviking New Member

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    Somebody is salty but yes it still has a diode.
     
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  7. Feb 22, 2024 at 9:08 AM
    #217
    Saltyhero13

    Saltyhero13 Throbbing Member

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    Encrusted, I sweat a lot.
     
    hagrid likes this.
  8. Feb 22, 2024 at 9:37 AM
    #218
    seahaul

    seahaul New Member

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    Looks cool, I like that it can be adjusted to two different settings and has a fuse!
     
    Saltyhero13[QUOTED] likes this.
  9. Feb 22, 2024 at 9:53 AM
    #219
    Chad D.

    Chad D. New Member

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    I just cheat and have a 200w solar panel on my canopy roof. I can set the voltage where I want it with the solar charge controller…. Keeps them Odysseys super happy.
     
  10. Feb 22, 2024 at 11:04 AM
    #220
    danno266

    danno266 n00b

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    Do you have a build thread somewhere?
     
  11. Feb 22, 2024 at 11:12 AM
    #221
    Chad D.

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    danno266[QUOTED] likes this.
  12. Feb 22, 2024 at 11:17 AM
    #222
    RCwyoming

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    Camp without the electronics.
     
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  13. Apr 2, 2024 at 4:10 PM
    #223
    Optic15

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    Has anyone used an add a fuse like this? I tried and didn’t see any change on my volts… charging at 13.6 volts when running. I’m also checking at my battery terminals, that’s how you’re supposed to right?

    IMG_1034.jpg
     
  14. Apr 2, 2024 at 4:11 PM
    #224
    daveeasa

    daveeasa FBC Harness Solutions

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    Wrong hole
     
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  15. Apr 2, 2024 at 4:35 PM
    #225
    Optic15

    Optic15 New Member

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    Thank you for pointing that out. Bumped me up a whole .2-.3DCV lol may just ride this out till I’m willing to upgrade my alternator. Or go maybe go solar for that trickle charge idk all I know is that I have a lot of accessories that need lots of juice
     
  16. Apr 2, 2024 at 6:16 PM
    #226
    daveeasa

    daveeasa FBC Harness Solutions

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    What your charging voltage? My ‘02 is older tech and with hkb (I did add a fuse diode while waiting for the HKB) I charge at 14.3-14.7 ish.
     
  17. Apr 2, 2024 at 7:08 PM
    #227
    Optic15

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    Pretty sure, assuming I was testing it correctly I’m charging at 13.9 now, where as prior it was 13.6
    My USBC charger has a voltage reading of 13.9 as well
     
  18. Apr 2, 2024 at 8:27 PM
    #228
    daveeasa

    daveeasa FBC Harness Solutions

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    K, that sounds low to me. I’m guessing 2.0 gen has more smarts than first gen does? I like my two old trucks for how dumb they are, easy to fool.
     
  19. Apr 2, 2024 at 8:36 PM
    #229
    ZPhilip

    ZPhilip Custom title here

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    What’s the correct orientation of the fuse and diode in that assembly?
     
  20. Apr 2, 2024 at 8:41 PM
    #230
    daveeasa

    daveeasa FBC Harness Solutions

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    Bottom slot, wrong way should show a dash light.
     
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  21. Apr 2, 2024 at 9:29 PM
    #231
    SLA10

    SLA10 New Member

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    Difference between charging voltage on cold start and trickle voltage after that. My truck will push 14.2v on cold start and drop to 13.7 or so after a few min of run time. I run an agm, but just top it off with an agm charger about once a month or so. If you test it first thing in the morning on a cold start you'll likely see a slightly higher voltage.
     
  22. Apr 2, 2024 at 9:37 PM
    #232
    Optic15

    Optic15 New Member

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    I got up to 14.1 when I was driving earlier and then as it darkened outside and I ran my lights, fogs, and light bar on in addition to my sound system running. It only dropped to 13.8. So I definitely got a jump with the diode, I guess I’ll find out with time if it’s enough.
     
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