is midnite solar is the best charge controller in the world?

[James1079]

Thanks Mike. A good friend of mine had just told me about the acid in plumber's flux that's why I mentioned it. I will cut and redo the wires. Yes I understand the question mark was in the title, and like I said no offense to the moderators, I hope one day that I can help to teach people also, I understand that your purpose is to help people understand solar principles. I guess sometimes that requires editing other people's words to fit the general understanding of the public? LOL. Could I get a quick advisement on string configuration? I think three in a string is my Max for this controller?

[James1079]

"Plumbers flux is ACID core "

the plumbers flux I used was just to dip the copper wire in. The sodder I used was rosin core electric solder. I guess I would have been better off just not using the extra flux?

[Mike90250]

To size your panel strings. I need 2 numbers
1) The Voc number from the sticker on the back of the panel
2) the max input voltage of your controller

[James1079]

To size your panel strings. I need 2 numbers
1) The Voc number from the sticker on the back of the panel
2) the max input voltage of your controller

1) 37.1
2) 150
at four panels that comes out to 148.4 which is pretty darn close to 150. I think the true question is how much error margin does the Trina solar panel or the Morningstar 60 give me. I'm on the 43-degree latitude in Michigan and once in a blue moon we have some pretty clear cold mornings

[jflorey2]

at four panels that comes out to 148.4 which is pretty darn close to 150. I think the true question is how much error margin does the Trina solar panel or the Morningstar 60 give me. I'm on the 43-degree latitude in Michigan and once in a blue moon we have some pretty clear cold mornings

Safer to assume no voltage margin. Figure out the coldest temperature the panels will _ever_ see (weather stations usually have almanac data for this) then figure out what Voc they will produce based on the temperature coefficient (listed in the panel's data sheet.) That will give you max voltage.

[James1079]

Safer to assume no voltage margin. Figure out the coldest temperature the panels will _ever_ see (weather stations usually have almanac data for this) then figure out what Voc they will produce based on the temperature coefficient (listed in the panel's data sheet.) That will give you max voltage.

I'm not sure what the equation is for that can you show me? My closest weather station is fox farms in Portland Michigan

[Mike90250]

I will say with GREAT confidence, that your 4 panels in series will FRY a controller with a 150V limit.

Your best option is 2 panels in series, parallel with the other 2 series panels, gives 70V, well under the kill voltage. and enough voltage to charge 24V bank.

[James1079]

I will say with GREAT confidence, that your 4 panels in series will FRY a controller with a 150V limit.

Your best option is 2 panels in series, parallel with the other 2 series panels, gives 70V, well under the kill voltage. and enough voltage to charge 24V bank.

I have 12 panels total and a 48 volt battery Bank. I was thinking three panels in series on four strings?

[Mike90250]

Sorry, lost count of all the panels, so yes, 3 series in a string would be under the kill voltage of the Controller. 2 in a string would be marginal to EQ a 48V bank.

[James1079]

So two would be the most efficient? but 3 would save me some wire and breakers?

[littleharbor]

Being 60 cell panels their voltage isn't high enough to charge a 48 volt battery when only 2 in series. 3 in series is really your only option for a 48 volt system.

[James1079]

Being 60 cell panels their voltage isn't high enough to charge a 48 volt battery when only 2 in series. 3 in series is really your only option for a 48 volt system.

I have just two panels connected right now until the weather's nicer to mount the rest and it seems to be charging the battery. do I need to hook up one more

[littleharbor]

Yes.

[James1079]

Yes.

I am watching the Morningstar training video and it mentions to reach 99% efficiency you need 48 volts in and 48 volts out

[littleharbor]

I am watching the Morningstar training video and it mentions to reach 99% efficiency you need 48 volts in and 48 volts out

For their MPPT controller? Regardless your panels aren't 24 volt panels. They are considered 20 volt nominal so 2 in series is a 40 volt nominal voltage which will not PROPERLY charge a 48 volt bank. 2 in series will keep your batteries from discharging below a certain point, but won't top off or equalize them. If you don't mind replacing your batteries on a regular basis , then, by all means stay with 2 in series.