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    PV with Arduino and 12Volt Sealed Lead Acid battery

    I have bought this solar charger (Epsolar-LS0512E): https://www.manualslib.com/manual/97...12.html#manual , a 12 Volt Sealed Lead Acid battery, and I use this solar panel:

    Voltage: 12V Peak Power: 40 W Number of Cell: 36 Pcs Short Circuit Current (Isc): 2.47 A Open Circuit Voltage (Voc): 21.82 V Maximum Power Current (Imp): 2.27 A Maximum PowerVoltage (Vmp): 17.6 V

    I want to supply a load, and by reading the solar charger manual it says to use fuses. I use special cable (4mm) for DC current from solar panel to the solar charger. My question is what fuses should I use? Is there any special fuses for PV? Should I take care of something else? It is the 1st time I use PV and I don't know how to proceed...

    Can I use this: https://learn.adafruit.com/adafruit-...akout?view=all connected to the LOAD position of the Epsolar-LS0512E, so that I get measurements or will destroy anything?

    Thank you!

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    Re: PV with Arduino and 12Volt Sealed Lead Acid battery

    as you have written:
    the solar panel provides up to 2.5 A short circuit current, less under normal use
    4 mm (about 6 AWG) is a bit big 2mm (about 12 AWG) should be big enough
    how big a wire can you connect to the solar panel?
    how big a wire can you connect to the Epsolar-LS0512E?

    solar panel charger manual says to use fuses
    does it recommend a size and location?
    generally, the fuses protect what comes before against a fault that comes later
    in your case, the fuses are to protect the solar panel charger
    i suggest putting the fuse in the high side to the load
    i suggest a fuse like this
    https://www.littelfuse.com/~/media/e...asheet.pdf.pdf

    start with a 2A for safety the first time or two

    unless you need remote monitoring, the adafruit current sensor shouldn't be necessary
    you aren't looking at high side voltage

    i haven't seen the manual for the charger-only what is posted on amazon
    https://www.amazon.com/EPsolar-LS051.../dp/B01M317ZGV
    a plain voltmeter should do


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    Re: PV with Arduino and 12Volt Sealed Lead Acid battery

    I believe you should first determine what current your load will draw. I see on page 15 it recommends 2 times rated current fuse is connected with battery and load. Not sure how to interpret this. Whether it's 2 times load current. Or 2 times maximum current rating of controller which is 5 amps.


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    Re: PV with Arduino and 12Volt Sealed Lead Acid battery

    I use 2 meters cable from the solar panel to the charger. From the charger to the battery and from the charger to the load I use 30 cm cable, not 4mm, but the common copper wire that can handle 4-5 Amperes. So, can I connect the INA219 to the LOAD position? Ok, I will use 5A fuses? The circuit I expect to draw around 1A max. I do not know what Amperes does a 12 Volt 2,4Ah Selaed LEad Acid battery needs.... Thank you....



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    Re: PV with Arduino and 12Volt Sealed Lead Acid battery

    You might consider 5 amp fuse between battery and controller. Then lower rated fuse from controller to load as wwfeldman suggested.


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    Re: PV with Arduino and 12Volt Sealed Lead Acid battery

    Thank you! What about the INA219? Can I connect it to the load position? Thank you...



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    Re: PV with Arduino and 12Volt Sealed Lead Acid battery

    When charging, the solar panel and the charger will safely charge the battery

    the battery does not "need" current
    it will provide the current the load requires, at 12V.

    the energy contained in the battery when it is fully charged is (12V) * (2,4Amperre hours)
    at 3600 seconds/hour, 8640 coulombs
    at 12 volts, 103680 joules

    that energy will come out of the battery to the load at whatever current the load requires
    the fuse will protect the battery and the charger in case of a fault at the load

    you specified a 1A load current
    The circuit I expect to draw around 1A max
    so a 2A fuse should be enough to allow operation and provide safety

    the IN219 is intended for high side operation. your load is not high side
    you can use a simpler device

    your cable selection looks okay.
    the 4mm is the diameter you specified in the first post
    I use special cable (4mm) for DC current from solar panel to the solar charger...


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    Re: PV with Arduino and 12Volt Sealed Lead Acid battery

    Can't we see the load position of the charger as the high side and the load as the low side? Do I miss something here? Thank you...



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  9. #9
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    Re: PV with Arduino and 12Volt Sealed Lead Acid battery

    the load position of the charger goes to the load
    same two wires, same points, except for minor voltage drop in wires

    "high side" is used when discussing power converters
    certain types of power converters have switches with one side connected to ground
    and some switches connected to the high voltage side.
    the switches connected to the high voltage side are "high side"
    one needs to add specialized circuits to control and monitor high side

    you do not have that situation
    you are essentially connecting the battery across the load
    the battery voltage and the voltage across the load are the same, except for minor
    voltage drop in the wires, which you can ignore



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