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  1. #1
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    Re: 12 V DC Chiller Build



    .

    250Amp battery is 1Amp for 250 hours, 250 Amp for 1 hours or any combination in-between.

    A quick calculation with 3.5 kW load would require 1 kW input so your battery would last about 3 hours......
    If my maths is correct???

    Rob

    .


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  2. #2
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    Re: 12 V DC Chiller Build

    Yes your right Maths is good.

    Rob what can i do.

    Spal Fan 8 A per Hour 2 Fans 16A per Hour what a Kompressor can i use Danfoss Bd250 12 V ?

  3. #3
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    Re: 12 V DC Chiller Build

    Just need to ask - is the 250amps the battery capacity or its CCA cold cranking amperage (to start and engine)?

    According to the bd250 data sheet it should be around 7-8amps at -15C, see page 22 -
    https://www.google.co.uk/url?sa=t&so...or81YW7-fYMqJe
    Last edited by Brian_UK; 02-12-2018 at 11:01 PM.
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  4. #4
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    Re: 12 V DC Chiller Build

    Hello Brian

    The Battery is 12V 200Ah Deep Cycle 800A/EN sorry fro my bad English.

    thanks for helping ,i see to page 22 max Ampere 4400 rpm 19,18Amps per hour

    20A+16A=36A (16 A 2 x Spal Fan)
    200A:36A=5,5 Hours of running ?

  5. #5
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    Re: 12 V DC Chiller Build

    Agreed 19amps at maximum load.

    This load will reduce as the refrigerant load is pulled down towards your design temperature. Once at temperature the compressor operation will be further reduced as it comes under thermostat control.
    Brian - Newton Abbot, Devon, UK
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  6. #6
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    Re: 12 V DC Chiller Build

    Quote Originally Posted by yilmaz22@gmx.de View Post
    Yes your right Maths is good.

    Rob what can i do.

    Spal Fan 8 A per Hour 2 Fans 16A per Hour what a Kompressor can i use Danfoss Bd250 12 V ?
    .

    Brian has a good point. as the load is achieved it will reduce the demand on the battery
    but it might only get you and extra 1/2 hour. Is it not as simple as getting another battery
    and doubling your supply?

    It will be hard to reduce power drawn due to the motors and other components design
    there is no easy way to reduce demand but you can double capacity of battery and that
    might be enough?

    Regards
    Rob

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  7. #7
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    Re: 12 V DC Chiller Build

    Thanks Guys

    i will inform you in some days i start build this unit .

    best thanks .

    i wait your Ideas

  8. #8
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    Re: 12 V DC Chiller Build

    All well and good...but you should not drain a battery below 80% capacity.

    How is the battery recharged to continue the refrigeration cycle once down to temperature?
    I'm back on the Pale

  9. #9
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    Re: 12 V DC Chiller Build

    Hello Frank
    the unit charged only with 240V,the Refrgeration runs 5-7 Hours from the battery(i Hope)
    and chardged after the work .


    best thanks Guys

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