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johnm1's avatar
johnm1
Explorer
Jun 01, 2016

Battery monitoring (Trimetric type vs Panel mount type)

Please help me in understanding the pros and cons and maybe more importantly the differences between these types of units.

I can get panel mount volt meters that will also measure amp draw but based upon what I've read here, they do not keep track of amps in and amps out. Just amps out?

Whereas the Trimetric type counts both? So this way I can, at a glance, have a fairly good idea how much "juice" I have left in the batteries?

I like the pricing of the panel mount units much more. Can they be used in the same (or similar) way somehow?

Just to be clear, I'm looking at the 12V side.

Thanks,

25 Replies

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  • Shadow_Catcher's avatar
    Shadow_Catcher
    Explorer
    Jun 01, 2016
    We have a Victron battery monitor and it is set for SOC state of charge, simple easy to read.
  • brulaz's avatar
    brulaz
    Explorer
    Jun 01, 2016
    johnm1 wrote:
    brulaz - this meter was posted on here not that long ago but I had forgotten about it. I'll have to look into it some more.
    Yes that's where I found out about it
    Roy - That's the type of meter I was referring to in my OP. I think it'll only do amps out and not in, right?

    With either of these meters, how do I know what my SOC is without using the hydrometer? Does voltage give you enough info?
    First you check the calibration, both V and A of the meter. I Compared it to the read out of my Solar Charger and a clamp-on ammeter.

    And then you fully charge your batts, guesstimate their fully charged Ah, and set the meter. I chose 400Ah, close enough?

    So now relative to my guesstimate, it calcs the % of max (400) and the current Ah. I haven't been using it much for the last few weeks, the trailer is unplugged from shore power in storage, and now the % is 100% and Ah is 401 Ah in the afternoon when it's floating. They do say that after a while it will get of sync, depending upon how good your initial calibration is.

    I just found the pdf of the ebay unit. Looks like it can give you the remaining AH of the battery (aka - battery fuel gauge).

    "Setting the Rated Battery Capacity
    Such resets are necessary for the initial installation of either the meter or a battery, so
    that the Elite meter correctly display the actual remaining capacity of the battery.
    1. Determine the rated capacity of the battery, expressed in Amp-hours, eg 100 Ah.
    2. Using the SET button on the panel meter, step to the third item of the debug menu.
    3. The LED labelled AH, to the right of the panel meter, will light up.
    4. The bottom line of the numerical display will show the battery capacity (Ah).
    5. If the reading is the same as the rated battery capacity, then quit debug mode.
    6. If the reading differs from the rated battery capacity then adjust the meter.
    - 4 -
    7. Press the V/W button to increase the reading to the rated value, or press the A/AH
    button to reduce the reading to the rated value.
    8. Save the settings by pressing the:
    - SET button to step the debug menu through to save-settings (ES),
    - V/W button to change the display from –n- (No) to -y- (Yes), and SET button to
    confirm the selection."
  • johnm1's avatar
    johnm1
    Explorer
    Jun 01, 2016
    brulaz - this meter was posted on here not that long ago but I had forgotten about it. I'll have to look into it some more.

    Roy - That's the type of meter I was referring to in my OP. I think it'll only do amps out and not in, right?

    With either of these meters, how do I know what my SOC is without using the hydrometer? Does voltage give you enough info?


    I just found the pdf of the ebay unit. Looks like it can give you the remaining AH of the battery (aka - battery fuel gauge).

    "Setting the Rated Battery Capacity
    Such resets are necessary for the initial installation of either the meter or a battery, so
    that the Elite meter correctly display the actual remaining capacity of the battery.
    1. Determine the rated capacity of the battery, expressed in Amp-hours, eg 100 Ah.
    2. Using the SET button on the panel meter, step to the third item of the debug menu.
    3. The LED labelled AH, to the right of the panel meter, will light up.
    4. The bottom line of the numerical display will show the battery capacity (Ah).
    5. If the reading is the same as the rated battery capacity, then quit debug mode.
    6. If the reading differs from the rated battery capacity then adjust the meter.
    - 4 -
    7. Press the V/W button to increase the reading to the rated value, or press the A/AH
    button to reduce the reading to the rated value.
    8. Save the settings by pressing the:
    - SET button to step the debug menu through to save-settings (ES),
    - V/W button to change the display from –n- (No) to -y- (Yes), and SET button to
    confirm the selection."
  • RoyB's avatar
    RoyB
    Explorer II
    Jun 01, 2016
    I too went with the individual panels meters for my project which I have two 12VDC VOLTMETERS and ONE 0-70ADC CURRENT meter. This was several years back before all of the nice meter panels are now available...

    This was mounted on the back of a SPECIALITY Three Gang Light Switch and Electrical box from LOWES and is mounted vertical in my monitor position......


    The two DC Voltmeters just ties into my main Battery selector switch and measures each battery bank Dc VOLTS. The DC Current meter is using the DC CURRENT Transformer method and is just in front of the Battery selector switch and measures the DC current being drawn from the selected batteries showing a minus symbol in front of the reading. This current meter also measures how much current the selected batteries are demanding from the on-board converter/charger setup when connected to shore power or my 2KW Generator. The meter panel shows just a DC current meter reading without the minus symbol when in this mode.

    This is quick schematic showing my hookup


    The only thing I wish I had was a auot alarm whenever my 12V Meter drops to around 12.0VDC telling my my battery banks is at its approximately 50% charge state...

    All installs are certainly different. Just showing what I did here for my setup to get you to think of different ways to do this... This may not be you cup of tea at all haha...

    They have come out with a couple of monitor panel meters real cheap using a panel that shows all of this info on it... NICE...


    I do alot of camping off the power grid (sometimes a couple of weeks at a time) and this is my primary way not to allow my batteries to drop below their 50% charge state so that i don't damage them...

    Roy Ken
  • brulaz's avatar
    brulaz
    Explorer
    Jun 01, 2016
    My ~$32 panel mount from ebay measures both amps in and out and amp-hours.
    But I've got it set up to measure net total amps in and out. It all depends where and how you place the shunt. Works fine.

    ebay link

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