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  • #61
    Originally posted by Cajun Bill View Post
    Just a quick note: got camper back today, but have not had time to analyze the batt AH nor to run my Kill-a-Watt meter on the fridge and freezer. i did notice, however, that my 12V PSW Xantrex inverter is 600W (not 1500W as I stated previously). Don't get excited SK, I agree that I will probably have to change that out for a 24V inverter. BTW, I will be "out of pocket" for the next few days, but asap, I will run all the numbers and repost to get the latest and greatest advice. thx again to all. I'm learning a lot from all this.

    P.S. still waiting for neighbor to tell me if she will sell me the greenhouse so that will be part of my decision as to what I will end up trying to power.
    That Xantrex inverter is nice (I have one myself). Don't get rid of it because you will find a use for it somewhere else on a 12volt system like your car some day.

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    • #62
      Okay, I was out of town for a few days, but while I was gone, I had both the fridge and the chest freezer plugged into my Kill-a-Watt meter and it appears that over an 80 hour period, they used 11KW so if my math is correct, it takes 3.3KW per day to run both or are my computations incorrect? Now I will unplug one from the KAW to see what one will draw and report back.

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      • #63
        Latest update: ran the KAW on just the chest freezer and it used 3.76KW in 48.25 hours which I compute to a rate of 1.87KW/day. That being the case, it means the fridge uses 1.43KW/day. With that in mind, is it feasible with my proposed setup to run either one of these appliances? I don't think I could do both without destroying my batts.

        BTW, my neighbor decided to keep her greenhouse so that idea to run the aquaponics pump on this proposed system is not happening, at least at this point. That is why I'm back to considering running one of these appliances again.

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        • #64
          Ok. Don't get the wrong labeling. According to your measurements that chest freezer uses on average 1.87kW in a 24 hour period or ~45kWh a day (1.87kW x 24hr = 44.8kWh).

          Is that correct or do you mean 1.87kWh a day?

          If the value is 45kWh a day that is a lot for a single load since my home uses that much a day which includes my 3 Ton AC unit, 25 cuft fridge, lights, TV's, fans, pool pump, computers, etc.

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          • #65
            I think I mean 1.87kWH a day. My computations are based on the KAW figures which I figured are that the chest freezer used 3.76kW in a 48.25 hour time period. I divided 3,760W by 48.25 hours which I think gives me the watts used per hour then I multiplied that by 24 to get what I think is the use of 1.87kwh/day. Am I correct and if so, is that feasible with my proposed system?
            Last edited by Cajun Bill; 08-24-2016, 09:31 PM.

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            • #66


              Watts is like horsepower. Saying "Watts per hour" is like saying "horsepower per hour" and wouldn't mean much here. But watts multiplied by time equals energy (watts X hours, AKA watt hours). Burning a 60 watt bulb for two hours uses 120 watt hours. But you swerved into the right number, which is 1870 watt hours per day. equation.jpg
              Last edited by sdold; 08-24-2016, 09:50 PM.

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              • #67
                Originally posted by SunEagle View Post

                As Sunking and Sensij state your best bet is a MPPT type charge controller. You should be able to get ~ 45amps out of the 2 x 280watt panels charging a 12volt battery. The battery system should have a rating somewhere between 360 and 540Ah.

                A typical 6v battery for an RV is rated about 230AH so 4 of them wired for a 12volt system would get you about 460Ah which is just fine with 45amps of charging.

                The problem you might have is that a 460Ah battery system can safely provide about 1380watt hours daily which is about a 25% discharge of a 460Ah 12v battery system. Hopefully your freezer and fridge do not use more than that amount or you will hurt the life of the batteries.
                SE, I went back and reread your post above. Two questions: if my fridge takes 1.43kW/day and my freezer takes 1.87kW/day, it appears that I am right on the line as far as using my proposed system for either appliance (but only one, not both), but "mo better" if I do the fridge rather than the freezer? If I follow the majority of recommendations and use the batts in series to get 24V thereby using a 24V CC, do my AH stay the same therefore making this possibly feasible?
                Last edited by Cajun Bill; 08-25-2016, 12:16 PM.

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                • #68
                  Originally posted by Cajun Bill View Post

                  SE, I went back and reread your post above. Two questions: if my fridge takes 1.43kW/day and my freezer takes 1.87kW/day, it appears that I am right on the line as far as using my proposed system for either appliance (but only one, not both), but "mo better" if I do the fridge rather than the freezer? If I follow the majority of recommendations and use the batts in series to get 24V thereby using a 24V CC, do my AH stay the same therefore making this possibly feasible?
                  Unfortunately when you wire batteries in series the voltage adds up but the Ah stays the same. So with 4x 6v 230Ah batteries you can get;

                  1) wire them in 2 pairs of 2 for a 12v 460Ah = 5520 watt hours system.
                  2) wire them 4 in series for a 24v 230Ah = 5520 watt hours system.

                  It is all the same except at 24volts you draw lower amps and can use small wire.

                  That is why running big loads like air conditioning or refrigerators make a solar / battery system expensive.

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                  • #69
                    or add 4 more batteries (in series for 48V) and you get 48V, 230Ah, 11,040Wh
                    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

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                    • #70
                      Any thoughts on this charge controller? The price is right, but wondering if it is "cheap China stuff"? The reviews look good also.

                      https://www.amazon.com/dp/B015ZBOFIG?psc=1#Ask
                      Last edited by Cajun Bill; 08-28-2016, 04:43 PM. Reason: to add link

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                      • #71
                        or even better.................. the reviews seem to indicate it is a better unit

                        https://www.amazon.com/TRACER-3215RN.../dp/B008KWPGAE

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                        • #72
                          The Tracer is a known OK brand
                          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


                          • #73
                            Okay, thought long and hard about it and I really want to order either the Midnight Kid or the Morningstar, but gonna be chintzy and order the Tracer for now. My thought process is that this is just an experiment/hobby so I can get a small solar project under by belt and although it will never be cost effective for what I'm doing, I want to keep the cash outlay as small as possible. I will also be ordering a 24V MSW inverter (any suggestions on that would be appreciated also).

                            Now to help me size the wire please: I will be wiring the panels in series so the amps should be less than 15A if my calculations are correct. The panels will be about 15 ft. away from the controller, then from the controller to the batteries will be less than 5 ft and the batts will be less than 5 ft. from the inverter. What are your thoughts? I'm thinking I can use wiring the same size as the what is presently on the panels as they come from the factory which I believe is 10 Gauge, but might be a tad bigger. If that is correct, what about the wire between the CC and batts; then the wire between the batts and the inverter. Should that be 2 gauge or larger?

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                            • #74
                              Originally posted by Cajun Bill View Post
                              Okay, thought long and hard about it and I really want to order either the Midnight Kid or the Morningstar, but gonna be chintzy and order the Tracer for now. My thought process is that this is just an experiment/hobby so I can get a small solar project under by belt and although it will never be cost effective for what I'm doing, I want to keep the cash outlay as small as possible. I will also be ordering a 24V MSW inverter (any suggestions on that would be appreciated also).

                              Now to help me size the wire please: I will be wiring the panels in series so the amps should be less than 15A if my calculations are correct. The panels will be about 15 ft. away from the controller, then from the controller to the batteries will be less than 5 ft and the batts will be less than 5 ft. from the inverter. What are your thoughts? I'm thinking I can use wiring the same size as the what is presently on the panels as they come from the factory which I believe is 10 Gauge, but might be a tad bigger. If that is correct, what about the wire between the CC and batts; then the wire between the batts and the inverter. Should that be 2 gauge or larger?
                              UPDATE: Well, bought the Tracer and installed it with 12V temporarily. Used 10 AWG from PV panel to CC, used 4 AWG from Battery to Blue Sea switch, then 4 AWG to CC, 4 AWG from CC to inverter (all runs less than 5 ft.). Hooked everything up, one 12V battery first connected to charger, then the PV panel of one 280W to the CC and then the CC to the 12V inverter. Well, green lights indicated the batts were being charged and PV panel was providing 32V then I turned on the inverter which chirped then nothing. Checked the voltage output of the Tracer and it was less than one volt (actually .25V). Don't know what it was before the inverter chirped, but can only assume it should have been 12V. I rechecked all my circuits and I'm sure everything is correct. Bottom line, I took the inverter out of the circuit and jumped it to the battery and it worked fine so my only conclusion is that the CC failed. Boxed it up and am sending it back to Amazon. Then I bit the bullet and ordered a Morningstar 45A MPPT CC which I will temporarily use on 12V. Figure when I convert that to 24V system, it should be able to handle my upgrade needs if I decide to try to run the fridge and freezer. (Should have listened to SK and SE in the beginning, but I'm hard headed.)
                              Last edited by Cajun Bill; 09-09-2016, 03:09 PM.

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                              • #75
                                Originally posted by Cajun Bill View Post

                                UPDATE: Well, bought the Tracer and installed it with 12V temporarily. Used 10 AWG from PV panel to CC, used 4 AWG from Battery to Blue Sea switch, then 4 AWG to CC, 4 AWG from CC to inverter (all runs less than 5 ft.). Hooked everything up, one 12V battery first connected to charger, then the PV panel of one 280W to the CC and then the CC to the 12V inverter. Well, green lights indicated the batts were being charged and PV panel was providing 32V then I turned on the inverter which chirped then nothing. Checked the voltage output of the Tracer and it was less than one volt (actually .25V). Don't know what it was before the inverter chirped, but can only assume it should have been 12V.
                                Hold the bus and wait a minute, you gotta a wiring problem.

                                If you had the battery, charge controller, and Inverter correctly wired it is impossible to see anything other than 12 volt battery voltage. There is no way a 24 volt charger can make a 12 volt battery go to 24 volts unless something is terrible wrong. If you are certain the battery is good, then you had to have something wired up incorrectly to see anything greater than 12 volt battery. Only place you would see higher voltage is at the Input of the Charge Controller from the panels. Anything with the battery connected to the output of the Charge Controller will be 12 volts even if the Controller is fried.

                                I have a clue and a hunch what is going on with some of the voltages you mentioned. The only way to see 32 volts out of your controller is if the battery is not connected properly. The output wires of the controller are terminated directly to the Battery Term Post through a fuse. The Input of the Inverter is connected directly to the Battery Term Post through a fuse. Make sno difference if the controller is turned on, panels hooked up or not, night or day, you wil see nothing but battery voltage.

                                The diagram below is not exactly what you have. Just Ignore the Green wires and what is left is exactly how you should be wired up.

                                Last edited by Sunking; 09-09-2016, 03:50 PM.
                                MSEE, PE

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