Testing actual power of Panels

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cswaite
cswaite Solar Expert Posts: 46 ✭
in Solar Beginners Corner #1
Ok. Quick question. If my charge controller shows for example 5.5 AMPS coming in on the display of the controller, but when I put my multimeter leads to the positive and negative screw going into the controller it shows 6.5 AMPS, would the correct Amps, be the reading from the meter rather than the controller (which I think is probably not so accurate). I bought one of the Juta controllers, I know they arent the best controllers, was just wondering what others think my correct AMPS would be in this situation.

Thank You
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  • dwh
    dwh Solar Expert Posts: 1,341 ✭✭✭
    #2
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    Re: Testing actual power of Panels
    cswaite wrote: »
    Ok. Quick question. If my charge controller shows for example 5.5 AMPS coming in on the display of the controller, but when I put my multimeter leads to the positive and negative screw going into the controller it shows 6.5 AMPS, would the correct Amps, be the reading from the meter rather than the controller (which I think is probably not so accurate). I bought one of the Juta controllers, I know they arent the best controllers, was just wondering what others think my correct AMPS would be in this situation.

    Thank You

    I would place more trust in the multimeter testing the wiring from the panels directly than I would in the display of the controller.

    Are the screws tight on the wiring going into the controller? (Just checking.)
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  • cswaite
    cswaite Solar Expert Posts: 46 ✭
    #3
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    Re: Testing actual power of Panels

    Yes, the screws are tight. I might buy a higher quality charge controller.

    Do you think even if the controller is displaying approx. 1 amp below what the meter says I am still getting that 1 amp to the batteries?
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  • dwh
    dwh Solar Expert Posts: 1,341 ✭✭✭
    #4
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    Re: Testing actual power of Panels
    cswaite wrote: »
    Yes, the screws are tight. I might buy a higher quality charge controller.

    Do you think even if the controller is displaying approx. 1 amp below what the meter says I am still getting that 1 amp to the batteries?

    I doubt it. More likely the controller display is showing what is going into the batteries, while the missing 1a is what the controller is consuming.
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  • n3qik
    n3qik Solar Expert Posts: 741 ✭✭
    #5
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    Re: Testing actual power of Panels
    cswaite wrote: »
    Ok. when I put my multimeter leads to the positive and negative screw going into the controller

    This is the incorrect way to test amps. That is the way to test for voltage.

    To test for amps/current, you need to remove one wire from the panel going to the controller. Then take one wire from meter and attach it to that wire from panel. Now take the other wire from the meter and attach it to the controller lug you just removed the wire from.

    This is called a series connection, this is how you measure amps.
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  • cswaite
    cswaite Solar Expert Posts: 46 ✭
    #6
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    Re: Testing actual power of Panels
    n3qik wrote: »
    This is the incorrect way to test amps. That is the way to test for voltage.

    To test for amps/current, you need to remove one wire from the panel going to the controller. Then take one wire from meter and attach it to that wire from panel. Now take the other wire from the meter and attach it to the controller lug you just removed the wire from.

    This is called a series connection, this is how you measure amps.

    Ok, ill give it a try. Thank you.
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  • icarus
    icarus Solar Expert Posts: 5,436 ✭✭✭✭
    #7
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    Re: Testing actual power of Panels

    I suggest that you read the manual for your multi-meter as many can only handle some number of milliamps, not full current 6.5 amps!

    A good way to toast a meter if you do it incorrectly.

    Icarus

    PS. that is what shunts are for!
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  • cswaite
    cswaite Solar Expert Posts: 46 ✭
    #8
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    Re: Testing actual power of Panels
    icarus wrote: »
    I suggest that you read the manual for your multi-meter as many can only handle some number of milliamps, not full current 6.5 amps!

    A good way to toast a meter if you do it incorrectly.

    Icarus

    PS. that is what shunts are for!

    My meter has a 10AMP DC setting.
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  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    #9
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    Re: Testing actual power of Panels
    cswaite wrote: »
    My meter has a 10AMP DC setting.

    You may also have to move one of the meter leads, to a jack on the meter
    labeled 10A
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