Constant Voltage Regulation voltage / Absorption Charging voltage

kansas
kansas Solar Expert Posts: 100 ✭✭
in Solar Beginners Corner #1
My Trimetric meter asks me to input a percentage of the charge controller's absorption charging voltage. My charge controller literature provides information on its constant voltage regulation voltage, but makes no mention of absorption charging. I would like to have confirmation that, as I believe, the two terms are functionally equivalent. Thanks.
Two 140 watt Kyocera panels, wired in parallel; Ironridge top of pole mount; two 6 volt, 242 AH US batteries, wired in series; Morningstar ProStar 30 charge controller and SureSine 300 inverter; Trimetric 2025-A meter; IOTA DLS-45 charger, Honda EG3500X generator; Aermotor 702 water pumping windmill.
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  • vtmaps
    vtmaps Solar Expert Posts: 3,741 ✭✭✭✭
    #2
    Re: Constant Voltage Regulation voltage / Absorption Charging voltage
    kansas wrote: »
    My Trimetric meter asks me to input a percentage of the charge controller's absorption charging voltage. My charge controller literature provides information on its constant voltage regulation voltage, but makes no mention of absorption charging. I would like to have confirmation that, as I believe, the two terms are functionally equivalent. Thanks.

    I have a trimetric... I don't recall inputting any such value. Are you asking about charge efficiency factor or charged setpoint voltage?

    --vtMaps
    4 X 235watt Samsung, Midnite ePanel, Outback VFX3524 FM60 & mate, 4 Interstate L16, trimetric, Honda eu2000i
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  • kansas
    kansas Solar Expert Posts: 100 ✭✭
    #3
    Re: Constant Voltage Regulation voltage / Absorption Charging voltage

    You're right. The input is the charged setpoint voltage, which is a percentage of the charge controller's absorption charging voltage. So you have to know the absorption volatge before you can input the setpoint. Hence, my question.
    Two 140 watt Kyocera panels, wired in parallel; Ironridge top of pole mount; two 6 volt, 242 AH US batteries, wired in series; Morningstar ProStar 30 charge controller and SureSine 300 inverter; Trimetric 2025-A meter; IOTA DLS-45 charger, Honda EG3500X generator; Aermotor 702 water pumping windmill.
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  • vtmaps
    vtmaps Solar Expert Posts: 3,741 ✭✭✭✭
    #4
    Re: Constant Voltage Regulation voltage / Absorption Charging voltage
    kansas wrote: »
    You're right. The input is the charged setpoint voltage, which is a percentage of the charge controller's absorption charging voltage. So you have to know the absorption volatge before you can input the setpoint. Hence, my question.

    The charged setpoint voltage is the charge controller's absorption voltage. You want the trimetric to reset when 'end amps' is achieved. That means the voltage is at absorption voltage and the current has declined to the 'end amps' value that indicates 100% SOC.

    You should set the trimetric's charged setpoint voltage to be 0.1 volt below your controller's absorption charging voltage... if you set the trimetric and the controller to the same voltage, minute calibration differences may mean the trimetric sees .01 volts less than the controller and the trimetric will think the charged setpoint voltage was never reached.

    --vtMaps
    4 X 235watt Samsung, Midnite ePanel, Outback VFX3524 FM60 & mate, 4 Interstate L16, trimetric, Honda eu2000i
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  • kansas
    kansas Solar Expert Posts: 100 ✭✭
    #5
    Re: Constant Voltage Regulation voltage / Absorption Charging voltage

    Thanks - I appreciate your analysis of how the Trimetric works and why it is important that the CSV is not the same as the charge controller's ACV, but must be set below the ACV by 1% or 2%.

    My question is really simple.

    My CC's specs don't speak of absorption charging. Instead, they refer and give a value for something called "constant voltage regulation voltage." What I asked is if anyone knows whether those terms - "constant voltage regulation voltage" and "absorption charging voltage" - are functionally equivalent. My belief is that they are.
    Two 140 watt Kyocera panels, wired in parallel; Ironridge top of pole mount; two 6 volt, 242 AH US batteries, wired in series; Morningstar ProStar 30 charge controller and SureSine 300 inverter; Trimetric 2025-A meter; IOTA DLS-45 charger, Honda EG3500X generator; Aermotor 702 water pumping windmill.
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #6
    Re: Constant Voltage Regulation voltage / Absorption Charging voltage

    We'll have to ask what charge controller this is but ...

    Standard RE charging terms and meaning:

    Bulk: as much current as is available to charge with, rising Voltage as charging occurs turns to

    Absorb: Voltage held steady, current decreases over time until triggered to

    Float: Voltage held steady, current fluctuates against varying loads as long as enough power is available from PV.

    Cycle repeats.


    Some companies use "Bulk Voltage" instead of Absorb, and some have a Bulk Voltage peak which then drops to a slightly lower Absorb level and then lower yet for Float. Much of this is done in a vain attempt at mimicking the charging available from AC sources where you can hold either current or Voltage steady depending on which stage of charging you are in.

    In my opinion "constant voltage regulation voltage" (got to be a Chinese low-dollar controller with language like that in the manual) would be Absorb because that is the charge stage where Voltage level is fixed (Float being more of a 'system maintain' stage).
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  • kansas
    kansas Solar Expert Posts: 100 ✭✭
    #7
    Re: Constant Voltage Regulation voltage / Absorption Charging voltage

    Thanks. That was my analysis.

    It's a Morningstar controller, which, as it turns out, won't charge. See my most recent post. It is made in Taiwan, but is not low dollar. Just had to send their voltage meter back when they announced the RM-1 would not function properly with their 300 watt inverter, though that is precisely how they market it. "A low priority software issue they may address in the future."

    Bill
    Two 140 watt Kyocera panels, wired in parallel; Ironridge top of pole mount; two 6 volt, 242 AH US batteries, wired in series; Morningstar ProStar 30 charge controller and SureSine 300 inverter; Trimetric 2025-A meter; IOTA DLS-45 charger, Honda EG3500X generator; Aermotor 702 water pumping windmill.
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #8
    Re: Constant Voltage Regulation voltage / Absorption Charging voltage
    kansas wrote: »
    Thanks. That was my analysis.

    It's a Morningstar controller, which, as it turns out, won't charge. See my most recent post. It is made in Taiwan, but is not low dollar. Just had to send their voltage meter back when they announced the RM-1 would not function properly with their 300 watt inverter, though that is precisely how they market it. "A low priority software issue they may address in the future."

    Bill

    Traditionally their products have been good quality and good value. I hate to say it but there appear to be more problems cropping up of late, and their technology is lagging behind. To say nothing of their value. They recently introduced a 30 Amp MPPT controller to compete with the Kid but it's just a re-hashed TriStar that sells for $70 more. They also brought out a 600 Volt MPPT to compete with the Xantrex/Conext unit and not only is it higher priced it is lower current.

    Morningstar better get its act together fast, I'd say.
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