Help My solar panel don't work as it should.
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Everyone is confused about what he has. If he has 2 CC then that requires two separate independent solar arrays feeding a common battery. After re-reading it also sounds like he might have 2 series panels in parallel with 3 panels in series. Something is not right, just cannot tell what.MSEE, PEComment
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As I try to remember. all the negetive wires are conneced to the disconnect/combine box beside the inverter and the charge controller. The box has a large 125amps braker and three small 20 amps brakers. two of the 20 amps brakers connected to the 12 original panels and the other 20amp braker connected to the 8 new panels.Comment
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No Paul that is not what we are asking. We know the panel wattages. It is th efull spec we need an dhow they are configured.
P-Max
Voc
Vmp
Imp
Isc.
How are they arranged? You cannot mix panels of different wattage without sacrifices. If in series the Imp is limited to the lowest value in the series string. Fo rexample if one panel is 7 amps and the other is 8 amps you only get 7 amps and you loose 9% of your power.
If in parallel the voltage is limited to the lowest value. For is one is 30 volts, and all others are 35 volts you only get 30 volts and loose 10% of your power.
What it sounds like to us from your description you have 2 panels in series in parallel with 3 panels in series. If that is the case you have eliminated 1 of the 5 panels and just as well throw it away or sell it.
The 8 new panels are rated 250watts per panel. I connected them 4 in one series and other 4 in another series. each series connected on a 10 amp braker and then combine the two braker into one positive wire to a seperate CC. I think there is only two negative wires go down that one for each controller.
Thank you.Comment
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Second point is how are the panels arranged and what are the specs of the panels? All we know is 235 watts and you have 12 of them. I can only assume being 235 watts they are grid tied panels. Bu tthey could be 60, 72, 90 cell panels. Need to know at least the Vmp and Imp. Not woried too much about Voc in Jamaica mon because if it freezes in Jamaica we know everyone on the face of earth is dead from nuclear winter.
With 12 panels there are only three realistic possibilities of:
6 x 2
3 x 4
4 x 3
With 8 panels there are only two realistic configurations of:
2x4
4x2
Which would depend again on panel specs we do not know.
Assuming the panels are configured correctly and wiring is in good order what I think is going on is you just have way too much panel wattage for the batteries, and or the whole system is over sized. Very rare to oversize, but that is what I suspect at this point. I hope with that much panel wattage with a 48 volt battery is at least 800 Amp Hours, or no more than 1200 Amp Hours of battery capacity.
Only way you could realistically test the system is with a load box which you do not have access too, load the system down with a 6000 watt load which you likely cannot, or turn off the panels and let the batteries discharge down to around 50% DOD, then turn the panels back on at solar noon on bright sunny day.MSEE, PEComment
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OK with 2820 watts with 48 volt battery one can only expect at best is 55 to 56 amps. That is assuming the batteries are demanding that much charge. They would have to be pretty deeply discharge to demand that much if available. You really cannot tell. Only way to see what is really going on is at solar noon assuming a bright sunny day is to turn on enough load to force the demand to go above 60 amps and at 48 volt battery we are talking a 3000 watt or more load on the system. That is a huge load.
Second point is how are the panels arranged and what are the specs of the panels? All we know is 235 watts and you have 12 of them. I can only assume being 235 watts they are grid tied panels. Bu tthey could be 60, 72, 90 cell panels. Need to know at least the Vmp and Imp. Not woried too much about Voc in Jamaica mon because if it freezes in Jamaica we know everyone on the face of earth is dead from nuclear winter.
With 12 panels there are only three realistic possibilities of:
6 x 2
3 x 4
4 x 3
OK now you have bought 8 more and I assume you made a completely separate panel array consisting of 8 panels and another CC. That can be done. With 2000 watts @ 48 volt battery means a possible 40 amps of charge current. However like above only if the batteries and or load demand it. When added together both compound and add to get 100 amps. The batteries may or may not be able to use that much depending on DOD. Again the only way to really tell is either deeply discharge the batteries and leave turned off until solar noon on a bright sunny day, or now turn on a load that demands 100 or more amps and at 5000 watts highly unlikely you can out that much load unless you have well over a 5000 watt inverter and more than 5000 watt load devices. I just do not see that being realistic. That would be a very large Air Conditioner or electric cook top and Oven with all burners turned on.
With 8 panels there are only two realistic configurations of:
2x4
4x2
Which would depend again on panel specs we do not know.
Assuming the panels are configured correctly and wiring is in good order what I think is going on is you just have way too much panel wattage for the batteries, and or the whole system is over sized. Very rare to oversize, but that is what I suspect at this point. I hope with that much panel wattage with a 48 volt battery is at least 800 Amp Hours, or no more than 1200 Amp Hours of battery capacity.
Only way you could realistically test the system is with a load box which you do not have access too, load the system down with a 6000 watt load which you likely cannot, or turn off the panels and let the batteries discharge down to around 50% DOD, then turn the panels back on at solar noon on bright sunny day.
Thank you.Comment
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So how many days have you been sucking that 48V battery bank down to 46V? Do you have a temp compensating SG tester for the batteries?1150W, Midnite Classic 200, Cotek PSW, 8 T-605sComment
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Paul first thing you need to do is either start up your generator connected to the SMA inverter and get your batteries charged up, or even better connect commercial power to the inverter gen input to charge up th ebatteries before you destroy them.
Without panels specs I cannot help you anymore other than to say connect Commercial Power to the Inverter Gen Input and call it done. Commercial power will be a lot less expensive than battery power. Then when and if commercial power fails, you will have battery power and whatever the panels can provide. Otherwise when commercial power is up and running, you will be on commercial power.
What are you panels make and model number?MSEE, PEComment
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The 12 original panels are same equal panels, the are rated 235watt max. I put 4 panels connected in a series. meaning one after another. so the amps is the same and the voltage increase each panel add on. it is about 33 volt each and it give me 132 volts total series. I have 3 of those series. each series connected to a 10amps braker at the roof. one braker connected one positive wire and the other two brakers connected to one positive wire to go down to the CC.
The 8 new panels are rated 250watts per panel. I connected them 4 in one series and other 4 in another series. each series connected on a 10 amp braker and then combine the two braker into one positive wire to a seperate CC. I think there is only two negative wires go down that one for each controller.
Thank you.
If that is the case I do not know how you are getting the 40 to 45 amps that you mentioned in your first post. Something is incorrect with how the panels are wired.
More than likely you have more wired parallel which will increase your total system amps.Comment
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No battery is going to last long with a 100% daily DOD though and if you have done that for very long you may be dealing with a battery isuues not a panel problem.1150W, Midnite Classic 200, Cotek PSW, 8 T-605sComment
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It is pure speculation but I believe he is talking about the amps the CC is putting into the battery bank. I've felt behind on this topic since the get go.1150W, Midnite Classic 200, Cotek PSW, 8 T-605sComment
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For the last time what are your panel specs?MSEE, PEComment
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