Announcement

Collapse
No announcement yet.

Mixing Panels

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • #31
    Originally posted by Offgrid View Post
    You missing something,the inverter and the AC 15w bulb...not dc?
    No I am not missing anything except .6 watts you just told me about. The math is staight foward.

    Battery capacity = voltage x amp hours = watt hours.

    12 volts x 102 AH = 1224 watt hour capacity.
    20% of 1224 wh = 245 wh
    factor out the wattage element to get time in hours = 245 wh / 15.6 watts = 15.7 hours.
    MSEE, PE

    Comment


    • #32
      My apologies

      So now what, I can only assume the voltage after 5 hours rest was not conclusive... Only thing I can think is my battery is stuffed or nor not charging properly but I don't want to assume because I am new at this.

      I have a small charger.Do you think I should charge it over night tonight at about 1 amp and then let the solar take over in the morning and if it still doesn't last close to 15 hours assume the battery needs to be replaced?

      Comment


      • #33
        Originally posted by Offgrid View Post
        My apologies
        No apology needed, especially on forums. I'm tuff, you cannot hurt my feelings that easily

        Originally posted by Offgrid View Post
        So now what, I can only assume the voltage after 5 hours rest was not conclusive...
        No done in the manner of letting it rest is conclusive the battery is at 100% state of charge. But the problem is SOC has nothing to do with battery capacity. It does not tell you the condition of the plates, electrolyte, and internal resistance.

        How are you measuring the voltage after letting it run 5 hours?

        Did you disconnect the battery at let it rest for a few hours?

        SOC voltages are completely meaningless when there is either a charge or discharge current operation. Only real time measurement of SOC is not with a volt meter. For real time data you have to use a lab quality temperature compensated hydrometer.

        I can take a brand new battery, fully charged and load tested at 110% of rated spec, put enough load on it and the voltage will drop to 10 volts instantly. That would indicated a completely shot battery. Take the load off and the voltage jumps right back up to 13 volts.

        If you really want to load test the battery to find the capacity I can tell you how to build a Poor Man's James Bond method using nothing more than a volt meter, hydrometer, and car head light.
        MSEE, PE

        Comment


        • #34
          Did you disconnect the battery at let it rest for a few hours?
          What I did was after a day of charging on solar.I disconnected every single thing from the battery so it was the battery alone and nothing on the terminals.This was on 12.88 and went to 12.82.During this time nothing was drawing on the battery and voltage readings were taken frequently.


          SOC voltages are completely meaningless when there is either a charge or discharge current operation. Only real time measurement of SOC is not with a volt meter. For real time data you have to use a lab quality temperature compensated hydrometer.
          I agree,problem is its a sealed maintenace free battery so no place to stick the hydrometer in. hehe

          I can take a brand new battery, fully charged and load tested at 110% of rated spec, put enough load on it and the voltage will drop to 10 volts instantly. That would indicated a completely shot battery. Take the load off and the voltage jumps right back up to 13 volts.
          Dear Lord,please dont say its so i my case.

          If you really want to load test the battery to find the capacity I can tell you how to build a Poor Man's James Bond method using nothing more than a volt meter, hydrometer, and car head light.
          Its a sealed battery,I am gathering its not possible we do a James Bond thing to test?

          Comment


          • #35
            Ok I think I found the problem,battery couldn't have been charged since I left overnight charging and then on the solar charging the next day and now I'm getting about 2 hours more,**** hope the battery's did not sulphate too much hopefully if there was any sulfating , the crystals arnt too hard and some of it has dissolved in the charging chemical process.Would this be a good time to do a equalize charge???

            Comment


            • #36
              AGM / sealed batteries not not get an equalize cycle. It will destroy them.

              After they have been in float an hour and have cooled off, re-boot the system, and let them go through another absorb cycle, they should weather that OK. Go to the Mfg's website and see what they recommend.
              Powerfab top of pole PV mount (2) | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
              || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
              || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

              solar: http://tinyurl.com/LMR-Solar
              gen: http://tinyurl.com/LMR-Lister

              Comment


              • #37
                Originally posted by Offgrid View Post
                Would this be a good time to do a equalize charge???
                No they are AGM or sealed. Consult manufacture for EQ settings and times.
                MSEE, PE

                Comment


                • #38
                  Thanks Mike,Sunking. Will do...interesting side note.I think I the the cause of the under charge. I measured those DIY panels again today again.Together (in parallel) the only producing 17v and 3 amps (50watts MAX) and they were paralleled to my new 100watt panel meaning I'm loosing 50w in total.Do you agree to toss the DIY panels and just use the new 100w panel? Should give the 102ah battery a better charge?

                  Comment


                  • #39
                    If you have a good AC charger, charge the battery up for 24 hours.
                    MSEE, PE

                    Comment


                    • #40
                      Alright I will do that but should I rather use the 100w alone or keep the other DIY panels too?

                      Comment


                      • #41
                        Sunking went through this a few posts ago but I am not sure if you have picked up on it.

                        how are you determining your DOD,

                        I think? you may be using the volt reading while the battery is under load to determine DOD.

                        As sunking posted to get a volt reading to use as a state of charge you need to rest the battery "after charging", you did that and got your 12.88

                        But you also need to do that "after loading" the battery, the volt meter reading under load is not indicative of the battery SOC, you need to load it for say 5hrs, then disconnect and rest it for 5 hrs, then check the voltage, then use that voltage to get an idea of the DOD%

                        Comment


                        • #42
                          Originally posted by Offgrid View Post
                          Alright I will do that but should I rather use the 100w alone or keep the other DIY panels too?
                          Huh?

                          If you have an AC powered battery charger, plug it in the wall socket, and let it run for 24 hours. Solar is not in the picture.
                          MSEE, PE

                          Comment


                          • #43
                            Lol, I was asking ( besides the AC charging topic which I am charging while I speak on a AC charger) if I should remove my 50 watt panels from my 100 watt new panel as I'm loosing 50 watts having the 2 in parallel.

                            Comment


                            • #44
                              @ Bala,I must of missed the SOC under load is not accurate part,thanks will try that and revert as I knew a SOC was not true under CHARGE but was not sure if it was true under LOAD.That helps.Will re read this thread again to find that part.

                              Comment


                              • #45
                                SOC voltages cannot be used on any active real time system. It is only somewhat accurate on a fully rested battery.
                                MSEE, PE

                                Comment

                                Working...
                                X