Amp Meter Recommendation

bcripps
bcripps Registered Users Posts: 16 ✭✭

Looking for a DC capable, clamp-on amp meter. My boat has a very simple solar system: 2-50 watt panels, a Midnight Brat, 2-80 amp batteries used mainly to power fans, charge computer and phone. Can someone recommend a simple, clamp-on amp meter (available on Amazon), with basis features that I can use to check the system. Budget: under $50

Thank you everyone...

Bry


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  • BB.
    BB. Super Moderators, Administrators Posts: 33,433 admin
    edited October 2022 #2
    If you are looking for a AC+DC current clamp DMM, this one seems to be a good deal (note, as always, link is FYI to start your search, I/We are not connected to these links/websites. Do your own searches for products and suppliers):

    https://www.amazon.com/UNI-T-Digital-Handheld-Resistance-Capacitancer/dp/B0188WD1NE (around $50 USD & good enough for our needs)

    An FYI for a mid range AC+DC clamp meter:

    https://www.amazon.com/Auto-Ranging-Resistance-Klein-Tools-CL800/dp/B019CY4FB4

    There are also DC AH/WH meters that can be permanently installed. Note: Most (almost all) DC current/power meters use a precision shunt resistor to measure current. Only AC power lines can use a Current Transformer to measure current flow.

    DC power meters typically only measure current AH/WH in one direction (i.e., the load is always consuming current):

    https://www.amazon.com/s?k=dc+power+meter&crid=B8C2D7SRNA47&sprefix=dc+powe,aps,1162&ref=nb_sb_noss_2

    There are battery monitors that count up and down and are intended to monitor the battery bank state of charge:

    https://www.amazon.com/s?k=battery+monitor&crid=21O2QJLISZZ3I&sprefix=battery+monitor

    There are very inexpensive monitors (above) and very nice high end monitors too (with alarms, Bluetooth, etc.):

    https://www.solar-electric.com/residential/meters-monitoring/battery-monitoring.html

    There  are Voltage based monitors and current/shunt monitors. Your choice. Note that all battery monitors can drift. Checking/confirming battery bank state charge with other methods (such as a hydrometer with flooded cell lead acid batteries) is still imporant.

    -Bill

    PS: Add that Solar-Electric.com / NAWS / Northern Arizona Wind & Sun founded and pays the rent for this forum. They have good pricing and great people & product support. I am a volunteer here and do not receive any payments from NAWS.

    This forum is for "everyone", and purchasing from NAWS or elsewhere is your choice.

    -Bill "full disclosure" B.
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • bcripps
    bcripps Registered Users Posts: 16 ✭✭
    Thanx Bill. That UNI-T meter looks to be exactly what I'm looking for.
    Bry
  • littleharbor2
    littleharbor2 Solar Expert Posts: 2,040 ✭✭✭✭✭
    edited October 2022 #4
    bcripps said:
    Thanx Bill. That UNI-T meter looks to be exactly what I'm looking for.
    Bry
    I have one and I really like it. I also have a Klein brand and I find the Unu-T model easier to use.

    2.1 Kw Suntech 175 mono, Classic 200, Trace SW 4024 ( 15 years old  but brand new out of sealed factory box Jan. 2015), Bogart Tri-metric,  460 Ah. 24 volt LiFePo4 battery bank. Plenty of Baja Sea of Cortez sunshine.

  • BB.
    BB. Super Moderators, Administrators Posts: 33,433 admin
    A suggestion--To learn to use the Current Clamp Meter, try it on your car battery. Car off, head lamp on motor not running, lights on motor running, etc...

    Note that DC current flow has a +/- polarity (i.e., if battery is on left side of clamp or right side of clamp) so you can measure the direction of DC current flow (battery charging, not charging).

    For AC clamp current measurements, the simple clamp meter cannot determine the direction of current flow.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset