The final piece for my system.. panels.. 12v or 24v..??

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  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: The final piece for my system.. panels.. 12v or 24v..??

    There's not much difference between 4.3 Amps and 4.4 Amps. Switching things on/off it is not at all unusual to see numbers "bounce up and down" so to speak.

    The % PWM indicates the amount of time the controller spends "switched on" as it were to maintain levels. With only one panel connected it needs to be on more to achieve the same output. This will not be a linear function either.

    I should make a video of the MX60 doing a sweep; it'd drive you crazy. :p
  • ywhicywhic Solar Expert Posts: 612 ✭✭
    Re: The final piece for my system.. panels.. 12v or 24v..??
    There's not much difference between 4.3 Amps and 4.4 Amps. Switching things on/off it is not at all unusual to see numbers "bounce up and down" so to speak.

    The % PWM indicates the amount of time the controller spends "switched on" as it were to maintain levels. With only one panel connected it needs to be on more to achieve the same output. This will not be a linear function either.

    I should make a video of the MX60 doing a sweep; it'd drive you crazy. :p

    So with 2 panels its on about 1/2 as much at 53%..

    If I added a 3rd panel would that have dropped it to another LOWER % number??

    Also I saw while testing:

    NITE (panels off)
    PWM
    BULK

    But I never saw FLOAT on the display.. when would that kick in?? Does my dead battery not holding AMPs have anything do do with that??

    And would a better battery show me some better numbers?? I have a good 12v battery here I can use..
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: The final piece for my system.. panels.. 12v or 24v..??

    With even more panels available to supply power (greater current potential) the PWM would 'switch on' even less often.

    NITE = no panel power detected; the charger thinks it is night time.

    PWM = charger is pulsing to try to maintain a Voltage set point.

    BULK = charger can not maintain V point with pulsed current; it switches to 'full on' Bulk mode.

    FLOAT = charger has gone through BULK and ABSORB completely and switches to lower FLOAT Voltage maintenance level.

    In normal operation what you should see is first thing in he morning it will switch from NITE to PWM when Voltage is detected at the input. It will try to hold a Voltage set point for FLOAT. It may run up and down a bit, changing PWM percent until it determines full charging is needed. It then goes to BULK, where it will stay until the battery is brought up to ABSORB Voltage level, then it will run PWM with varying % to maintain the V point against loads (if it can). After full ABSORB time has passed it will shift down to FLOAT and try to maintain that V point as long as it can. Again it will be running PWM as it switches on/off to keep the Voltage steady against loads. When it can't it will increase 'on' time until it hits BULK again (in accordance with the programming). When panel Voltage drops below the detectable minimum it will go back to NITE.

    Note that with a defective battery and not running through a whole charge cycle in sequence the controller operation will be erratic. You really do have to leave it be and let it sort things out for itself.
  • ywhicywhic Solar Expert Posts: 612 ✭✭
    Re: The final piece for my system.. panels.. 12v or 24v..??

    Thanks..

    Tommorrow is supposed to be clear and sunny all day..

    I will take a known good battery and setup 1 panel at like 8am.. to try an run an unattended cycle..

    I may have to end the cycle at like 2-3pm to go get mail.. but I will simply turn the panels off.. and it should hopefully think its NITE by then..

    This weekend I will show my 10 yo son how it all is connected up (since the cabin will end up being his sometime down the line)..

    Then I will pack up this last panel and put into storage till 'go day' when I go back to TX.. (hopefully later this year or next spring)..
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: The final piece for my system.. panels.. 12v or 24v..??

    Al;

    Here's a little general information for you about testing equipment: the most important thing is to eliminate as many variables as possible.

    You haven't really achieved this with your efforts. For one thing, the panels' outputs will change due to insolation, panel temp, and load. Switching them on and off will only aggravate the changes. But the worst is that dead battery. With a good battery you have a reasonable chance of predicting performance in accordance with the Peukart Effect, especially if you can measure actual SG and battery temperature to get a reliable SOC figure. A bad battery is a crap shoot: it can have all kinds of problems inside, from sulphated plates which make it perform like a smaller battery to open connections or shorts or erosion or invasion of alien tadpoles. You just never know what's gone on inside. That's why I repeatedly warn against buying used batteries, no matter how much of a 'bargain' they appear to be.
  • ywhicywhic Solar Expert Posts: 612 ✭✭
    Re: The final piece for my system.. panels.. 12v or 24v..??
    Al;

    Here's a little general information for you about testing equipment: the most important thing is to eliminate as many variables as possible.

    You haven't really achieved this with your efforts. For one thing, the panels' outputs will change due to insolation, panel temp, and load. Switching them on and off will only aggravate the changes. But the worst is that dead battery. With a good battery you have a reasonable chance of predicting performance in accordance with the Peukart Effect, especially if you can measure actual SG and battery temperature to get a reliable SOC figure. A bad battery is a crap shoot: it can have all kinds of problems inside, from sulphated plates which make it perform like a smaller battery to open connections or shorts or erosion or invasion of alien tadpoles. You just never know what's gone on inside. That's why I repeatedly warn against buying used batteries, no matter how much of a 'bargain' they appear to be.

    Thank you.. didn't buy it.. it was laying here and my brother in law offered it for testing..

    I will yank my car battery in the AM and use that.. its GTG.. and not stagnant either..
    (and no blackened positive terminal either.. LoL..)

    I will just switch on the 1 panel (other went back to storage) and I'll see what I can get.. I will just let it run for the 6 hours (no switching or playing with it)..

    Supposed to be 80'F and perfect..
  • ywhicywhic Solar Expert Posts: 612 ✭✭
    Re: The final piece for my system.. panels.. 12v or 24v..??

    Today with a good car battery I hooked 1 panel up..

    And I get this for readings.. 12.9V 0 AMPS 0 WATTS BULK..

    129Bulk.jpg

    The solar panel voltage screen says 13.4 volts coming in.. guess the battery needs NOTHING from the panels..

    I even hooked up a small auto 12v bulb.. still nothing..
  • BB.BB. Super Moderators, Administrators Posts: 29,218 admin
    Re: The final piece for my system.. panels.. 12v or 24v..??

    You appear to have a problem on your solar panel side... Either the panels are shaded (or sun not up yet) or there is a wiring problem. It appears that the controller is trying to pull 100% current from the array and it is getting none.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • ywhicywhic Solar Expert Posts: 612 ✭✭
    Re: The final piece for my system.. panels.. 12v or 24v..??

    Must have been the shading.. getting 19V at the combiner and 16-17 on the meter for the solar voltage..

    No showing 22 watts and 14.4V and 1.X amps.. PWM 34%
  • BB.BB. Super Moderators, Administrators Posts: 29,218 admin
    Re: The final piece for my system.. panels.. 12v or 24v..??

    Since you are reaching 14.4 volts at the battery--Everything seems to be functioning correctly (and you have a pretty full battery).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • ywhicywhic Solar Expert Posts: 612 ✭✭
    Re: The final piece for my system.. panels.. 12v or 24v..??

    Just a small update..

    I got my 10 AWG 37 Strand Tin Annealed Copper wire cut to length (with some extra).. since I'm going 24V now I only need 3 runs.. its got all the ratings on it.. XLPE, PV, 10AWG, 600V, 90'C wet/dry, sunlight resistant, ROHS, UL, -40 C, VW-1 or RHW-2 (2kv) and has a 6mm OD casing..

    Got 10, 15, & 20 feet pairs cut and crimped (one one end as the other end goes into the combiner box)..

    Panels will be at 4, 9, & 14 feet from the back wall.. I want the combiner box 4 feet up from the bottom of the cabin wall. I plan on burying the wire about 1 foot down to run it out to the panels.. I will have a small section of gray PVC coming from the ground to the conduit inlet coming in the building..

    PVWire.jpg

    Next will be getting the Bluesea Fuse Mount $20 and 125 amp fuse $15 for the proposed 220 ah starter 24v battery bank..
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