HO alternators

Discussion in 'Marine Electrical / Electronics' started by winterking, Feb 1, 2019.

  1. winterking

    winterking Captain

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    Last edited: Feb 1, 2019
  2. djmarchand

    djmarchand Captain

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    What are you trying to accomplish with an upgraded alternator?

    If you are a recreational boater who needs more battery recharging capability after a night or two on the hook then you also need an external regulator. And to hook up an external regulator you need an an alternator with the proper external connections to let you plug in the external alternator.

    Most internally regulated alternators which is where your link pointed to are set at a fixed voltage in the mid 13s. This won't provide much current particularly when your batteries get charged up to 75% of capacity. It takes well over 14 volts to push enough current into batteries at that charge capacity. That is what external regulators like those from Balmar do.

    For commercial operators who use power all day long while the engine is running it is probably less important to have an external regulator. In that case you are not trying to replace battery capacity, you are using the power as it is produced by the alternator, so the mid 13s voltage output works fine.

    So think about what you are doing so you can set up an alternator system that works for you.

    David
     
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  3. winterking

    winterking Captain

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    Thanks David, I appreciate your insight!
    I’m usually ideling, either deep dropping or tending gear overnight, I’m powering electronics, nav lights, small led deck lights. I like the idea that it puts out 55amps at low rpms, and it will fit in the small space same as original.
     
  4. djmarchand

    djmarchand Captain

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    Well if all you are doing is keeping up with small loads at night, that alternator should work for you. But I wouldn't expect it to produce 55 amps at idle. It will only do that if your batteries are almost dead.

    David
     
  5. Diesel Jerry

    Diesel Jerry Captain

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    Have you looked at Balmar?
     
  6. winterking

    winterking Captain

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    No I haven’t Jerry, but I’m gonna have a look now that you say that. Forgot about them, and theirs no doubt they’ve got a good reputation. I really want to keep it the same size wise so it fits back in the same place.
     
  7. djmarchand

    djmarchand Captain

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    I didn't want to push Balmar as they are expensive, probably $750 for an alternator/regulator package, and it sounds like you may not need their capability. But I do think that they are one of the best.

    They can provide an alternator to fit most marine engines.

    Are you having problems with your current alternator keeping up overnight?

    David
     
  8. winterking

    winterking Captain

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    I guess as I re read their info that’s why it says we build these units to provide “up to 55 amps at idle” instead of, provides 55 amps at idle. Tricky wordy for the uneducated. (Me)
    I’m going to look at the balmors as Jerry mentioned, I think the oem alt is 51 amps, have no clue what it puts out at idle, really looking to get a little more output at lower rpm range, if that makes any sense.
    Thanks for the continued discussion from all, I appreciate the info.
     
  9. winterking

    winterking Captain

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    I’m trying to upgrade a few things, would like to have a bit more charging capabilities when everything is running over night. Noticed a slight drop in battery’s, I forget the numbers it wasn’t much, maybe I’m worrying to much but would rather err on the side of safety.

    Thx Tom
     
  10. Diesel Jerry

    Diesel Jerry Captain

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    Are you idling for long periods of time? That is not good to do if you are running a diesel. Do you know your amperage draw for all the loads you have on while idling?
     
  11. winterking

    winterking Captain

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    I’m not sure, I’d have to look it up. It’s not straight ideling all night, running 7-8 knots in between. Touch screen plotter, radar, 12 volt side lights, led red over white lights, two small led deck lights, bottom machine, old furuno gps 32, I think that’s about it.
     
  12. steveinak

    steveinak Captain

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    smaller pulley on alternator ?
     
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  13. TCL

    TCL Senior Member

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    Another potentially high draw item at low RPM's depending on the engine is the air pre-heaters. My previous boat with 4BT's would have great voltage/RPM swings as the heaters cycled on/off, disconnecting them solved the problem.
     
    TCL,
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