C40 optional digital display yes/no?

If I purchase a C40 charge controller, do I need the optional digital display if I also plan on using a Trimetric TM2020 battery monitor? What capability am I gaining if I do add the optonal display to the C40?

Thanks, Kevin


  • nigtomdawnigtomdaw Solar Expert Posts: 705 ✭✭
    Re: C40 optional digital display yes/no?

    The C40 will show battery voltage at current level, total watts being produced by your solar array, total amp hours recievied during a set period, ie daily if you remember to press and hold the reset button. and total amp hours recieved since unit was switched on ie only resets on power down !

    A trimeric is a battery monitor it counts the amps going in versus the amps going out of our battery bank thus can give you an educated guess on the state of charge of your battery bank, when set to Fully charged by the user it adds and substracts the power flowing in and out to give you a % readout of state of charge, the C40 s only let you know how much energy your solar array has produced and gives you a current battery voltage reading. HTH
  • nigtomdawnigtomdaw Solar Expert Posts: 705 ✭✭
    Re: C40 optional digital display yes/no?

    I have 2 C40 remote displays and from a systems health check point of view they are usefull showing the solar arrays output dynamically great for troubleshooting . I'm a follower of system instrumentation, apart from a battery monitor most system monitoring is relatively cheap voltmeters and ammemeters and can greatly assist in troubleshooting. and help you to understand whats going on in your personal power plant.
  • H2SO4_guyH2SO4_guy Solar Expert Posts: 213 ✭✭✭
    Re: C40 optional digital display yes/no?

    I ended up with a Trimetric after researching the meters available. I have 2 of the C-40's, but elected not to get the optional meter for either of them. The meter for the C-40 as many who had them felt they were a waste of money and the Trimetric was much better anyway.

    12K asst panels charging through Midnite Classic 150's, powering Exeltechs and Outback VFX-3648 inverter at 12 and 48 volts.  2080 AH @ 48 VDC of Panasonic Stationary batteries (2 strings of 1040 AH each) purchased for slightly over scrap, installed August 2013.  Outback PSX-240X for 220 volt duties.  No genny usage since 2014. 
  • rrbvrrbv Registered Users Posts: 16 ✭✭
    Re: C40 optional digital display yes/no?

    I also recommend the trimetric. Spend your money on a charge controller that is more efficient than the C40. A MPP type will make a lot more power, particularly in the winter when the days are short and you need it

  • icarusicarus Solar Expert Posts: 5,436 ✭✭✭✭
    Re: C40 optional digital display yes/no?

    I think the Trimetric is great. I use it but with a twist. I have an additional ammeter (cheap digtital w/shunt) on the panel side of the controller. That way, the Trimetric will show the total amps in/out of the battery bank, but the add on meter will show the difference between PV amperage and the MPPT amperage into the battery.

    For the sake of entertainment, there is no such thing as too many meters. In the car(s) I have a Scan Gauge that gives me all kinds of information I don't really need, but it cool to have. Intake manifold temp anyone?

  • nigtomdawnigtomdaw Solar Expert Posts: 705 ✭✭
    Re: C40 optional digital display yes/no?

    Im with Icarus monitoring is a pre requesite if off grid, I have a Battery Monitor by Xantrex XBM and two CMR.s for my 2 X40s. But I also have 3 analogue meters for my ACgenset imput, the upside is at a glance u can monitor solar imput battery % charge and check and tailor your genset runtime to get your batteries fully charged.

    I spent $30,000 on my current system and the monitoring side is a small % ask Backroad about neglecting your batteries....$3000k + in 12 months is the best advert for system monitoring:blush:
  • System2System2 Posts: 6,290 admin
    Re: C40 optional digital display yes/no?

    correct me if I am wrong . But hitting and holding the reset button also puts your charge controller in desulfate mode.

    Tojan does not recommend doing this under normal situations. Only when the specific gravity is off on the batteries to a certain point.

    If you did that daily you would be desulfating your batteries...Kicking 1 volt higher to kinda boil the batteries.
  • n3qikn3qik Solar Expert Posts: 741 ✭✭
    Re: C40 optional digital display yes/no?

    There are two buttons. One on the front only resets the accumulative watts on the display. The button on the side is to do a manual equalization.
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