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Controlling equalisation with an Epever AN controller.

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  • Controlling equalisation with an Epever AN controller.

    My questions relate to setting and controlling the equalisation for the Epever AN series of controllers. I have just commissioned my system and am learning how everything works. The controller does an equalisation on the 28[SUP]th[/SUP] of every month and the default time is 120 min.[LIST=1][*]Can I stop and start the EQ once it starts?[*]What happens if I switch the panels off in the middle of EQ? Does the controller keep timing or does it stop and re-start the clock?[*]What happens if the PV output is too low for effective EQ during the time period? Does this effect the total EQ time?[/LIST]
    The Trojan data sheet recommends an EQ voltage of 16.2V. This seems very high and I am worried that my 12V devices will be damaged by such a high voltage.
    What would be a lower voltage for a flooded Trojan that still gives effective equalisation?

    After doing some research I am beginning to wonder whether monthly equalization is really necessary, at least in my case. I have 550watts of PV at 48V and 460 Ah of Trojan Solar SPRE batteries connected as 12V. I have a steady 12v only load (no inverter) consisting mainly of security cameras and a modem/router. I believe my system is somewhat over designed and don't anticipate depleting the batteries very often. Perhaps I should just do a manual EQ every few months by fiddling with the date and timer in the controller.


  • #2
    Ideally, you should be monitoring the specific gravity of your battery fluid to determine if equilization is necessary. One like this, that compensates for the ambient room temperature would work best.

    Check Trojan's spec sheet for what your batteries should be, which I think will be around 1.275. You might want to equilize when the cell to cell, battery to battery variance in density is >0.015 units. That means if one battery has a density of 1.275, and another is 1.260, it is time to equilize. It's appropriate to shut off your inverter for a few hours if the battery's equilization voltage is above the inverter manufacturer's recommendation.

    If you have multiple strings of batteries in parallel, it might give you the best performance to equilize each string separately, to bring them all up to the same final SG.
    Last edited by MichaelK!; 07-01-2019, 03:49 PM.


    • #3
      According to EPEver the eq time will continue the next day if voltage drops too low.

      If you want to disable the eq, set it to 1 minute and set the voltage to just slightly higher than the normal charging voltages