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  • #46
    Originally posted by Niron View Post
    Same as in my screen data:

    When the sun rises, the PV voltage has not reached> 52.8V
    If One stage charger Constant Voltage, MPPT Buck Converter need PV Voltage > 52,8.

    PV Voltage 49.1V mppt it is already charging, this is CC mode.
    CC Mode = MPP(Max. Power Point) and
    Constan Current, when charger reach protection ampere setpoint.

    Comment


    • #47
      While the term CC in the PV world is in fact NOT correct I did already notice what you've said in your last 2 replies. See attachements.

      Since you've filled in the same voltage for float , do you think that your charger is now acting like a "float-charger" then?

      Ref lithium DIY POWERWALL:
      In your previous replies you've said that you've bought a BMS , thats it. I assume that you think your DIY powerwall is safe also because you're monitoring voltages.

      I find this a "dangerous" statement to let people beleive that, for example with a 40watt soldering iron, everybody can make a powerwall if they put a bms on it and monitor the voltages.
      Attached Files

      Comment


      • #48
        Originally posted by GeorgeF View Post
        While the term CC in the PV world is in fact NOT correct I did already notice what you've said in your last 2 replies. See attachements.

        Since you've filled in the same voltage for float , do you think that your charger is now acting like a "float-charger" then?

        Ref lithium DIY POWERWALL:
        In your previous replies you've said that you've bought a BMS , thats it. I assume that you think your DIY powerwall is safe also because you're monitoring voltages.

        I find this a "dangerous" statement to let people beleive that, for example with a 40watt soldering iron, everybody can make a powerwall if they put a bms on it and monitor the voltages.
        Dangerous statement?
        Show me, where is my statement.
        You know DIY terms.
        Not for you to discussion my diy powerwall.

        You statement only one stage CV charger is dangerous.
        Last edited by Niron; 09-22-2020, 11:50 PM.

        Comment


        • #49

          You are not DIY person, so no need to talk about my diy powerwall.

          Discuss your statement only one stage CV charger!

          Comment


          • #50
            It is for sure that I will not even think about of making a lithium powerwall myself at home. Im not crazy as I know my limits. I think most of the DIY Li guys overestimate themselves. Perhaps it is for you also wise to see other threads here about DIY lithium powerwalls, as an example see attachement.

            Ref charging:
            A moderator above and the "stickies" already explained what "constant current" in fact means. When charging your battery with PV only the term CC is in fact incorrect.

            You yourself did control the charging proses by defining ONE "constant voltage" only (13.2v x 4=52.8v) , no switching in between, no lower float voltage.

            If I may describe it , it is a "PV current/CV" scheme , regardless of the type of chargecontroller used, correct me if im wrong.

            And, if you have to use the current limited option of your MPPT perhaps you have to re-evaluate your design.
            Attached Files

            Comment


            • #51
              Originally posted by GeorgeF View Post
              It is for sure that I will not even think about of making a lithium powerwall myself at home. Im not crazy as I know my limits. I think most of the DIY Li guys overestimate themselves. Perhaps it is for you also wise to see other threads here about DIY lithium powerwalls, as an example see attachement.

              Ref charging:
              A moderator above and the "stickies" already explained what "constant current" in fact means. When charging your battery with PV only the term CC is in fact incorrect.

              You yourself did control the charging proses by defining ONE "constant voltage" only (13.2v x 4=52.8v) , no switching in between, no lower float voltage.

              If I may describe it , it is a "PV current/CV" scheme , regardless of the type of chargecontroller used, correct me if im wrong.

              And, if you have to use the current limited option of your MPPT perhaps you have to re-evaluate your design.
              Your focus only CC charging term, you forgot there is an MPP charging(Max Power Point=see datasheet) that works together in CC mode.

              You forgot if battery voltage has not yet reached constant voltage, the controller operates in constant current mode, delivering its
              maximum current to the batteries (MPPT Charging).

              As a said before, CC Charging term limited to a protection system that will not be active if the PV resource is smaller than the CC setpoint.

              I ask you again, where is Bulk Voltage?.
              My datasheet b
              Attached Files

              Comment


              • #52
                I think I"ve already answered. See my previous answer

                Comment


                • #53
                  Originally posted by GeorgeF View Post
                  I think I"ve already answered. See my previous answer
                  B Voltage?

                  My datasheet B voltage same as equalizing charging term.
                  And you can see screen print=equalizing time setting if lead acid

                  Comment


                  • #54
                    Perhaps I can shine a light on battery charging Algorithms. With the exception of the Nickel battery chemistry, all use Constant Current / Constant voltage. Now that may sound complicated, but is really easy to understand.

                    Any battery charger, DC Power Supply, Charge Controllers, etc can only supply so much charge current. They use use current limiting circuitry to limit current to a safe level for the charger. Otherwise the charger would burn itself up. A battery will take as much current as the source can provide only limited to the batteries internal resistance.

                    Example say you buy a 10-Amp CC/CV charger, a 12 volt 100 AH battery at 50% SOC. You set the voltage to 14.2 volts. Turn the charger on without the battery connected and you see 14.2 volts. You check the battery voltage before connecting and it reads 12.1 volts (OCV). You connect the charger and immediately you see 10-Amps going into the battery. You check the battery/charger voltage and it reads 12.2 volts. Why doesn't it read 14.2 volts where you set it too earlier.

                    Because the charger can only supply 10-amps, and had to lower (Fold Back) the voltage to limit the the current to 10-amps. When a battery is charging a battery, the Battery Voltage = OCV + (Amps x Ri)

                    Where OCV = Battery Voltage at rest on an open circuit
                    Amps = Charge Current
                    Ri = Battery Internal Resistance.

                    So 12.1 volts + (10-amps x .01 Ohms) = 12.1 volts.

                    Hours pass by as the battery keeps charging at 10 amps constantly. The battery voltage rises as it charges up. Battery voltage reaches 14.2 volts and we notice charge current starts to taper down toward 0. The voltage remains constant at 14.2 volts until charge currents drops to 0-amps as the battery is now fully saturated.

                    That my friends is CC/CV. Time for a wake up call. Bulk/Absorb, Float, Equalize, Boost or any other marketing term you want to call it to fool the public is CC/CV. The only difference between any of them is the voltage set point.

                    On a 12 volt battery, Boost/Absorb set point is 14 to 14.4 volts. Boost is the Constant Current phase, and Absorb is the Constant Voltage phase. Float would be 13.2 to 13.8 volts, and Equalize is roughly 15 to 16 volts.

                    So now let's look at a real CC/CV circuit. Extremely complicated circuit that takes 20 years of college education in the USA to figure out, or a 5th grade education in any other country.

                    ?u=http%3A%2F%2Fcdn.instructables.com%2FFU1%2FCKKV%2FG3TE0Z3G%2FFU1CKKVG3TE0Z3G.LARGE.jpg&f=1&nofb=1.jpg
                    MSEE, PE

                    Comment


                    • #55
                      Originally posted by Sunking View Post
                      Example say you buy a 10-Amp CC/CV charger, a 12 volt 100 AH battery at 50% SOC. You set the voltage to 14.2 volts. Turn the charger on without the battery connected and you see 14.2 volts. You check the battery voltage before connecting and it reads 12.1 volts (OCV). You connect the charger and immediately you see 10-Amps going into the battery. You check the battery/charger voltage and it reads 12.2 volts. Why doesn't it read 14.2 volts where you set it too earlier.
                      Of Course CC/CV

                      Example PV MPP 16V x 9A=144Watt
                      Say my charger controller 100% efesiensi.
                      I set 14,4V
                      I=P/V
                      I=144/14,4=10A

                      CC charging not reach.
                      So if CV charging = 12.1 volts + (10-amps x .01 Ohms) = 12,2V
                      P=10x12,2=122Watt
                      Charging efesiensi 122/144=84%

                      So if mpp charging?
                      Example if algorithm set 12,3V
                      I=144/12,3=11,7A

                      12.1 volts + (11,7-amps x .01 Ohms) = 12,211V

                      ​​​​​​P=11,7Ax12,111A=141Watt.
                      Charging efficiency = 141/144=98%

                      Correct me if i'm wrong
                      Last edited by Niron; 09-23-2020, 01:47 PM.

                      Comment


                      • #56
                        Originally posted by Niron View Post

                        Of Course CC/CV

                        Example PV MPP 16V x 9A=144Watt
                        Say my charger controller 100% efesiensi.
                        I set 14,4V
                        I=P/V
                        I=144/14,4=10A

                        CC charging not reach.
                        So if CV charging = 12.1 volts + (10-amps x .01 Ohms) = 12,2V
                        P=10x12,2=122Watt
                        Charging efesiensi 122/144=84%

                        So if mpp charging?
                        Example if algorithm set 12,3V
                        I=144/12,3=11,7A

                        12.1 volts + (11,7-amps x .01 Ohms) = 12,211V

                        ​​​​​​P=11,7Ax12,111A=141Watt.
                        Charging efficiency = 141/144=98%

                        Correct me if i'm wrong
                        ​​​​​​P=11,7Ax12,211A=142Watt.
                        Charging efficiency = 142/144=98,6%

                        Comment


                        • #57
                          Think our friend Niron is mixed up with the terms cause of his MPPT manual. They talked in the manual about "boost charging" in the "constant voltage" phase, see attachement

                          As I stated before, it can be very confusing when controller's manuals use the same terms as battery specs but with different meanings
                          Attached Files

                          Comment


                          • #58
                            Originally posted by GeorgeF View Post
                            Think our friend Niron is mixed up with the terms cause of his MPPT manual. They talked in the manual about "boost charging" in the "constant voltage" phase, see attachement

                            As I stated before, it can be very confusing when controller's manuals use the same terms as battery specs but with different meanings
                            Maybe the folks writing the manuals have have some of the same fluency problems with english as you and Niron have.

                            Comment


                            • #59
                              It is only complicated if you make it complicated. Example no solar charge controller made is capable of Constant Current, not possible. A top of the line MPPT Controller is a Power Converter. It can only charge Constant Power or Constant Voltage. Physics tells you it cannot do Constant Current.

                              Simple circuit analogy. Let;s say we have a perfect 100 watt solar panel, a 11 volt battery with a 10-Amp Charge Controller.. No matter what you do or think cannot change the fact the panel cannot generate any more than 100 watts no matter what a true hugging democrat says. So our battery is down to 10 volts, and we connect the panel and charger. Panel is generating 100 watts which develops 10 volts @ 10 Amps. You know this statement is true because watts = Volts x Amp. The math works and equals out the equation. .

                              Now our battery continues to charge and charges up to 10.75 volts. Panel is still generating 100 watts. How much battery charge current is there? If you said 10 amps are drinking tree hugger kool-ade. Current dropped to 100 watts/ 10.75 volts = 9.3 amps. That is not constant current, that is constant power. So any charge controller that claims constant current is full of it. Not possible.

                              Only way to have CC/CV is with a still source using commercial AC or a generator. In the above example a generator is not power limited using a solar panel current source. In the above example, to maintain constant current the power would have started at 100 watts. But as the battery charges starts drawing more power to maintain CC and at 10.75 volts would have to go up to 107.5 watts. A 100 watt panel cannot do that. At best, and does a piss poor job of it, is supply constant power. But if you get real the power is all over the place during the day. Never generates rated power, and peaks for 5 minutes at solar noon. You will never see constant current unless you are clipping off power throwing it away. Like over sized panels.

                              Sooner or later once you get your noodles wrapped around how it works realize all those names like Bulk/Absorb, Float, and EQ are just voltage set points. Not the magic marketeers made you think with their Smart Charger. and fancy confusing terms that have no meaning.
                              MSEE, PE

                              Comment


                              • #60
                                Originally posted by Sunking View Post

                                Sooner or later once you get your noodles wrapped around how it works realize all those names like Bulk/Absorb, Float, and EQ are just voltage set points. Not the magic marketeers made you think with their Smart Charger. and fancy confusing terms that have no meaning.
                                Yes of course, just voltage setpoint.
                                Algorithm do that.
                                ​​​​Bulk not Constant Voltage.

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