Eco-Worthy 160W

billybob9billybob9 Registered Users Posts: 141 ✭✭
 Five years ago I bought an Eco-Worthy solar system from amazon. It had 5 panels 160W that were 18V for a 12 volt system. A cheapy controller and hooked these up to a 12 volt battery system ( four 6 volts series and parallel ). I soon found out that any 12 volt system over 500w would start heating the wires ( and it did ). So I put another controller into my panels that were parallel and this cooled it down. This year I thought my cheapy batteries were about to die so I turned it into a 24 volt system to get the most out of them. Only paid $ 300 for 4 at Costco. Since my new test tools came ( Thanks Bill ) I decided to pull the whole system apart and test it. I tested every cell in the batteries one by one with the DC meter ( 2V per cell ) and they were all good. I charged the batteries with a battery charger and they took a full charge. Checked it the next day and they held the charge. Amazing. Now I would test each solar panel through the controller to a 12V battery ( two 6v ). What I found was the controller was seeing the panel but not allowing the 18V to go to the battery. I then checked the voltage directly from the panel and found the voltage to be 20V. So how could that be ? Then I remembered from youtube, a man from Australia who bought 2 flexing 100W panel. One was $300 and the other was $100. He tested both and found the cheaper one put out 1 Amp more then the expensive one. So he was blown away and threw up his hands. Then I realized that the Expensive panel was very shinny and the cheap panel was dull. Then I remembered a test in a book called Quantum Electro Dynamics that would explain this. Two panels the same size at the same angle to the sun would receive the same number of Photons. The shinny one would reflect more of these photons away and the dull one would absorb more. So what I believe is happening with my system is, with age my panels have got duller and the voltage has increased to the point that the controller will not let it through. I ordered a Mppt controller and will test again when it arrives....   

Comments

  • TecnodaveTecnodave Registered Users Posts: 437 ✭✭✭✭
    Billybob,
    when you connect things back togather it is important to connect the battery first, then the panels, try disconnecting the panels,  shutting off the power , wait a few minutes for the charge to disappate, reconnect power to controller then connect panels,   20 volts is not too high a voltage for an unloaded "12 volt" panel, some will be 21-22 volts with no load

    when powering down, shut off solar first, then shut off battery,  when powering on power the controller first, then connect the panels
    2 Classic 150, 2 Kid, 5 arrays 7.5 kw total  2ea.  2S6P Sharp NE-170/NE-165, 1ea. 12P Sanyo HIT 200,  2ea. 4/6P Sanyo HIT 200, MagnaSine MS4024AE, Exeltech XP-1100,  2 Banks L-16 battery, Rolls-Surette S-530 and Interstate Traction, Shunts with whizbangJr and Bogart Tri-Metric, iCharger i208B  dc-dc buck/boost converter with BMS for small form lithium 8S 16650 or LiFePO4,
  • billybob9billybob9 Registered Users Posts: 141 ✭✭
    Tecnodave

    I said the exact same thing you did in one of my posts about connecting the battery first. That's what I did and put a load on it.  It could be this controller is a goner. Thanks...  Well see when the Mppt arrives. 
  • littleharbor2littleharbor2 Solar Expert Posts: 1,654 ✭✭✭✭
    You're metering open circuit voltage when testing the panels. When connected to the controller and batteries the battery will clamp the Vmp. voltage (18 volts) down to the batteries voltage. The voltage rises as the battery charges. If the battery voltage could rise up to 18 volts, it eventually would.

    2.1 Kw Suntech 175 mono, Classic 200, Trace SW 4024 ( 15 years old  but brand new out of sealed factory box Jan. 2015), Bogart Tri-metric, 540 ah @24 volt AGM battery bank. Plenty of Baja Sea of Cortez sunshine.

  • PhotowhitPhotowhit Solar Expert Posts: 5,729 ✭✭✭✭✭
    @billybob9 said " This year I thought my cheapy batteries were about to die"

    Not unlikely, at 5 years old is not a bad life for golf cart bateries that are regularly cycle, particularly if youhave some pattern of heavy discharge once in a while.

    @billybob9 said "...so I turned it into a 24 volt system to get the most out of them."

    This won't help, a bad battery will draw them all down.

    @billybob9 said "....I tested every cell in the batteries one by one with the DC meter ( 2V per cell ) and they were all good."

    Voltage is NOT a good indicator of a good battery. A battery can have 2.1 volts per cell but no capacity. Better to load test them once they are fully charged. They make load testers, they introduce a heavy load and the voltage should drop at first then settle out and remain with only a small drop over a 3-4 minutes.

    @billybob9 said "Now I would test each solar panel through the controller to a 12V battery ( two 6v ). What I found was the controller was seeing the panel but not allowing the 18V to go to the battery."

    The charge controller is doing it's job! It's job is to be sure there is no more voltage than the battery needs to charge properly. If I ever saw 18 volts passing through a charge controller to a 12 volt battery, I would be on the phone yelling and screaming at the charge controller's manufacturer. 18 volts with just a small percentage of current would allow your batteries to over charge and become worthless.

    @billybob9 "I then checked the voltage directly from the panel and found the voltage to be 20V. So how could that be ? "

    You are measuring Open circuit voltage, under load it will be close to vmp, you are measuring voc (voltage open circuit)

    @billybob9 said "I ordered a Mppt controller and will test again when it arrives.... "

    Quite likely a complete waste of money. Did you check the specs for the MPPT controller? MPPT controller want voltage 30% above the charging voltage, for most efficiency you would normally run the panels in strings of 2, but you have 5 panels. Can the charge controller you ordered handle over 100 volts VOC? Many cheap ones can't.

    At rest your 12 volt battery bank will no higher than 12.7 volts, this is the battery voltage. While charging the voltage will rise above the battery voltage to what some call the system voltage.

    During charging, there are basically 3 stages of charging, Bulk, Absorb, and Float.

    BULK;
    First thing when charging starts you will be in bulk, the voltage rises from what ever the system voltage was to a set point, around 14.5 volts. At that point the Charge controller stops the voltage from rising. Higher voltage can damage sealed batteries.

    ABSORB;
    Once the battery hits the preset point the charge controller keeps it at that point. Your batteries are roughly 80% full. Flooded batteries will start accepting less current at 80-85% full AGM/Sealed may go a little longer before accepting less current.
    On many controllers you can set this point, Some will have different presets for Flooded, and sealed batteries, or flooded, AGM, and sealed batteries. 

    The charge controller has a couple ways to know when to switch to float, Most inexpensive Charge controller are just timed for 1.5-2 hours. Some will also see less current flowing through the charge controller and shut it down when minimal current is flowing through the controller. On more expensive charge controller. You can set battery capacity to give the Controller a better idea of when to stop. you can also set a longer Absorb time. Or set 'end amps' a amount of amps flowing through the charge controller to stop Absorb and switch to the final stage.

    FLOAT;
    Once the Controller has determined the battery is fully charged it reduces the voltage to a point where very little current is flowing to the battery. This will prevent the battery from over charging and heating up.

    While in 'Float' the charge controller watch for voltage drop, which would indicate a load. If the voltage begins to drop the charge controller will allow as much current to flow from the panels/array to compensate and maintain the voltage. If the voltage can be maintained, the load will in essence be running directly off the array/solar. If the voltage drops below the preset float voltage, the controller may start a whole new cycle if it stays there for a period of time.

    The system voltage drop you see at night when the sun goes down is the charge controller moving into a resting mode with no energy to contribute to the system.

    The morning voltage may reflect a load present that is effecting the voltage level. With sealed batteries, you would want to disconnect the battery from the system and allow it to 'rest' for a while to get an accurate idea of it's SOC (Sate Of Charge) from the voltage
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Magnum MS4024, Prosine 1800(now backup) and Exeltech 1100(former backup...lol), 660 ah 24v Forklift battery(now 10 years old). Off grid for 20 years (if I include 8 months on a bicycle).
    - Assorted other systems, pieces and to many panels in the closet to not do more projects.
  • billybob9billybob9 Registered Users Posts: 141 ✭✭
    I just put a 100W panel on the controller replacing the 160W panel and the controller started charging the battery right away. So that controller did not like the 160W. It's one of the older kind and I was just testing the panels anyway. I did it just in time as the sun is going down. Thanks for all the input . My new controller is a 40 amp so I might have to get serious about the stuff I buy now...
  • EstragonEstragon Registered Users Posts: 4,496 ✭✭✭✭✭
    billybob9 said:
     Then I remembered from youtube, a man from Australia who bought 2 flexing 100W panel. One was $300 and the other was $100. He tested both and found the cheaper one put out 1 Amp more then the expensive one. So he was blown away and threw up his hands. Then I realized that the Expensive panel was very shinny and the cheap panel was dull. Then I remembered a test in a book called Quantum Electro Dynamics that would explain this. Two panels the same size at the same angle to the sun would receive the same number of Photons. The shinny one would reflect more of these photons away and the dull one would absorb more. So what I believe is happening with my system is, with age my panels have got duller and the voltage has increased to the point that the controller will not let it through. I ordered a Mppt controller and will test again when it arrives....   
    It's possible a $300 panel has been subject to stricter Q.C., and a given sample panel  produces very close to spec, whereas a $100 one has a much wider range of variance to spec.  In an application where it's important for components to perform to spec values in order for the overall system to function properly, the extra cost may be acceptible. 

    It's also possible he simply paid too much for the $300 panel, or the $100 panel "fell off the back of a truck".

    As for degradation of your panels, I'd expect optical degradation (eg hazing/scratching) to show up as decreased Isc, but degraded wiring/connections, heating, etc to show decreased voltage.

    A paper on degradation rates (with discussion of causes in bibliograpy section near the end):

    https://www.nrel.gov/docs/fy12osti/51664.pdf
    Off-grid.  
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
  • billybob9billybob9 Registered Users Posts: 141 ✭✭
    Estragon

    After inspection of my panels I did notice hazing and scratches but as I did not take any electrical measurement when new I just believed the advertised numbers were correct. So no or little degrading appeared to have taken place. I did find a stripped screw on the panel which holds the connecting wire on the positive side. Since it wouldn't tighten completely this might be an area for a bad connection (I will replace this screw ). I looked up Eco-Worthy systems on ebay and found all systems of 160W panels totaling 640W  were 24V now with mppt controller on one. I had to look at the wiring diagram to figure out the systems volts. These panels are expensive if bought separately. Thanks 
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