mppt charge controller - ZLPOWER ??

[conntaxman]

solar panel connection

I have a small {lol} question in which way is the best/better way to wire panels. I'll use 4 panels, each 65watt x 3.5 amp x 18vdc. I guess im trying to get more amp's. I now have them all in parallel. Should I take Two and wire them in parallel and then take those and connect them to the other Two in Series. It would them be 36 vdc, ...BUT would it be 3.5 +3.5= 7AMPS, Then going through the Two in series 7 + 3.5 =10.5 amps at 36 vdc.
Tks
John

[billvon]

So why not spend an extra 50 to 100 bucks on a quality MPPT controller?

Potential reasons:

1) You don't need it (i.e. you don't need the extra power.)
2) You are combining outputs of several disparate panels.
3) You are combining outputs from panels oriented in different directions.
4) You are sensitive to EMI (electromagnetic noise.)
5) You have a diversion load you want to use.

[Sunking]

I'm not going to get into the technical issues at hand here, but wanted to make a comment. Why would someone scrimp on a cc when they have at least 100's of dollars (if not 1000's) invested in panels, and 100's of dollars (if not 1000's) invested in batteries.
So why not spend an extra 50 to 100 bucks on a quality MPPT controller? Unless you are a re-seller.

That being said, I do not have an MPPT controller, because I did not know about their existence.

It is not so much technical, but rather simple economics. As a rule of thumb below 200 to 300 watts in panels, economics dictate a PWM controller. Above 300 watts you cross the line and now MPPT becomes less expensive because it takes less panel wattage.

[pmaru77]

I'm not going to get into the technical issues at hand here, but wanted to make a comment. Why would someone scrimp on a cc when they have at least 100's of dollars (if not 1000's) invested in panels, and 100's of dollars (if not 1000's) invested in batteries.
So why not spend an extra 50 to 100 bucks on a quality MPPT controller? Unless you are a re-seller.

That being said, I do not have an MPPT controller, because I did not know about their existence.

[Sunking]

When you said Battery Wattage .. I think you implied Battery Voltage

Correct my bad, and yes you need a 40 amp controller

[Mike90250]

Battery Wattage is correct. Even more correct would be to call it Wattage Delivered to Battery, but it's the same thing really.

MPPT controllers work by watts in = watts out minus 5%.

Your Wattage Delivered to Battery is the same, to the limits of the controller
400W delivered at 12V = 33amps
400W delivered at 24V = 16amps

If you have chosen a battery voltage that hits the amps limit of your contrller, you need to re-design the system to a different voltage, or live with the losses you have chosen

[wbsolar12]

MPPT Charge Controller current is Panel wattage / Battery Wattage. So you have a problem because 960 watts \ 12 volts = 76 amps. So if you are running @ 12 volt battery you need a 80 amp controller. If you have a 30 amp MPPT controller it can only handle 350 to 400 watts, so you can only use one of your panels

When you said Battery Wattage .. I think you implied Battery Voltage,
Then you mean the Battery system voltage right not the individual battery right? Because my Battery is 12v connected 2 in series, so which makes it 24v. Still short as I need 38 amps ... ?

[Sunking]

MPPT Charge Controller current is Panel wattage / Battery Wattage. So you have a problem because 960 watts \ 12 volts = 76 amps. So if you are running @ 12 volt battery you need a 80 amp controller. If you have a 30 amp MPPT controller it can only handle 350 to 400 watts, so you can only use one of your panels

[wbsolar12]

Depends on how you measure it. IF you are using the Voc and Isc test that is correct. If you try to put a load on the panel then you have little of either voltage or current. Solar panels are current sources, not voltage

Sunking,

I've a charge controller rating question for you - am a newbie so not sure if I can open a new thread.

If my Solar Panels are 230w and I connect a string of 2 in series in parallel with another string of 2, totally 4 panels.

The Isc of each panel is 8.2 amps.

Charge controller am looking at is rated at 30 amps MPPT with 95v max input voltage.

Now, for Charge Controller Purpose :

Is this equivalent to 8.2*2=16.4*1.25~ 21 amps so I can use 30 amp MPPT ? (I am doing 8.2 x 2 because of the parallel connection)
OR
Is this equivalent of output of 920 watts/battery bank volt size => 920/24 = 38 ? so I have to upgrade to higher charge controller?

I am confused really whether this rated charge controller amperage is at the input side of the charge controller or the output of it?

I've seen experts using 2 ways to do it. Not sure which is right.

Thanks

[conntaxman]

panel

Russ, i know that, I was just wondering what readings are coming from a panel/panels in different day time conditions. Cloudy,sunny, raining, Mine were putting out voltage and amp's when it was snowing and gray clouds.Not much.
what readings do your panels put out.You must have volt and amp meter's on the input.
tks
John

[Sunking]

Am I right in saying the amperes are very low when it is cloudy,but you still get voltage.

Depends on how you measure it. IF you are using the Voc and Isc test that is correct. If you try to put a load on the panel then you have little of either voltage or current. Solar panels are current sources, not voltage

[Mike90250]

... Am I right in saying the amperes are very low when it is cloudy,but you still get voltage....
... Single panel would be better.

Volts, amps - it takes BOTH to produce power (watts)

Single panel is not "better", it's merely a single panel.

[russ]

Am I right in saying the amperes are very low when it is cloudy,but you still get voltage.tks
John

That is correct

[conntaxman]

panel

Question about panel output. I know it's hard to answer because every day is different. But I would like an idea or what people are getting out of their panel's/panel. Plus having the right angle too. But on a Bright cloudy day and a clear sunny day. Am I right in saying the amperes are very low when it is cloudy,but you still get voltage.
I know their are alot of factors.
so what are you getting off your panels or a single panel. Single panel would be better.
tks
John

[enerteq]

MPPT Controller

Hello,
yes, ZL Power vs. Victron Energy have the same controllers, I think Helior Technology is a white label OEM manufacturer.