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DC current limiter

Discussion in 'Misc Electronics' started by Kamus of Kadizhar, Jan 22, 2004.

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  1. Is there a currrent limiter that can limit 12VDC to < 60 amps?

    I have a situation with a deep cycle lead-acid battery where the 60 amp
    breaker trips when charging. I'd like to limit the current to reasonable
    levels and have continuous charging rather than spikes of > 60 amp
    current, breaker trips, resets, spikes, etc....

  2. You can make a current limiter for any current.
    But, There is a voltage burden in doing so.

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  3. Roger Gt

    Roger Gt Guest

    in message

    What are the cause of the spikes, what is the peak
    value (if known) and how long do they last?
  4. This is part of an RV charging system. There is a 60A breaker followed by
    a solenoid. When the engine is off, the solenoid is open and the starter
    battery is isloated from the RV battery.

    The problem comes in when the RV battery is depleted and you start the
    engine to charge it. The solenoid closes and the engine starts to charge
    teh RV battery. The current is greater than 60 A, so the breaker trips.
    It resets autmatically, but trips again and again until a series of these
    short cycles charges the battery enough so that less than 60 amps is
    required for charging.

    The problem is that some sort of breaker is needed; loads on RV batteries
    can be 100A or greater for short times (like when using a microwave) and
    you really want to isolate the car alternator from having to deal with
    loads like that.

    A battery isolator introduces a voltage drop (0.7 V or so) so I'm trying
    to see if a current limiter of some sort exists that does not have a
    current drop like that.

  5. Current drop like what? Did you confuse the voltage drop for a current
    Current limiting is inherently a voltage drop!
  6. He could put a low resistance across the breaker, say about 1 ohm.
    That would allow about a dozen amps to flow even when the breaker is
    tripped. What would make a cheap low resistance? Well, how 'bout a
    car headlamp? They're not expensive and they're easy to find. You
    might consider going to a junkyard to buy a sockete for it.

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  7. Fat finger typo.
    Well, yes. But I guess I'm looking for some sort of "intelligent" current
    limiter - one that gets out of the way if the current is less than 60 amps.

    I've found a DC-DC charger that might work; I'll contact the manufacturer.
  8. Ross Mac

    Ross Mac Guest

    There are battery isolators that have almost no drop..
    Here is one you might consider...
    Just do a google search and you will find others such as MasterVolt....Happy
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