How to wire up a solar panel kit?

[poot_traveller]

Here is the solar charge controller with the wires and connectors that came with the kit: https://ibb.co/xLM72kS

This is the pure sine wave inverter with wires and connectors: https://ibb.co/VQJT3Sz

And the solar panel wire connectors: https://ibb.co/Qbb1CrW

I have one pair of mc4 solar panel connectors on order so I can connect the solar panel to the wires.

I assume the white wire (which is quite long and has positive and negative wires in it) connects to the solar panel and the solar controller, correct?

Do I need to buy positive and negative wires to run from the battery to the controller?  The solar kit I got doesn't seem to have those wires.

The kit was suppose to have come ready to set up, does it look like I have everything to setup the solar panel kit?  (battery is still to come)

 

[Natgreen]

I didn't look at all the items. You're going to need wires to connect the panels. Then you will need wires coming off the string of panels to the charge controller. And yes, you need wires going from the charge controller to the batteries.

Any wire will do as long as it's the right gauge size. There are no special wires for positive and negative. They are the same though you may want to color code them. Red wire for positive. Black for negative. If all your wires are black you can use red electrical tape to identify the positive wires.

Hope that helps!

 

[poot_traveller]

Thanks. I only have one solar panel.  I have the wires for the solar panel to controller but not the battery to the controller.

Any guesses what the right gauge size will probably be for that?

 

[Natgreen]

You are going to have to figure out how many amps are going through the wire. You can Google wire gauge chart. How many amps does your panel generate? Do plan on adding more panels in the future?

Give a man a fish......

 

[B and C]

The longer the wire run, the larger the wire gauge needs to be to lessen voltage drop. Here is one of many such calculators: https://www.rapidtables.com/calc/wire/voltage-drop-calculator.html

 

[poot_traveller]

You are going to have to figure out how many amps are going through the wire. You can Google wire gauge chart. How many amps does your panel generate? Do plan on adding more panels in the future?

Give a man a fish......

My panel generates 160 Watts and maximum voltage is 17.8V, so it will be generating 8.98 amps.

I don't plan on adding more solar.

 

[poot_traveller]

The longer the wire run, the larger the wire gauge needs to be to lessen voltage drop.  Here is one of many such calculators: https://www.rapidtables.com/calc/wire/voltage-drop-calculator.html

The numbers on that calculator don't mean anything to me, I couldn't tell if that means it's a big voltage drop or not.

So basically I just need really thick wire for my whole solar kit. I think that's what you're saying.

 

[Natgreen]

It's not a bad idea to over gauge your wire. It will cause less resistance.

 

[B and C]

I used the biggest wire that would fit in my charge controller.

 

[Gypsy Freedom]

My panel generates 160 Watts and maximum voltage is 17.8V, so it will be generating 8.98 amps.

I don't plan on adding more solar.

if the max voltage is 17.8 the only time it will get that high is when there is no current flow.

most panels will be rated with several specs

max volage/open circuit voltage
max current/short circuit current
and peak power current
some may also include peak power volts

with a PWM controller the panel will run just slightly higher volts than the battery volts at any given moment

with an mppt controller the panel will run closer to the peak volts but not all the way up there. for example my 435 watt sunpower panels have a max voltage around 85 volts, but when charging the controller keeps them around the low 70 volt range. only once the batteries are getting close to full and the absorb phase is tapper off a lot will the volts go up higher. then when the batteries are full and the current drops to almost zero the panel volts come up to 84-85




when i size wires, i aim for less than 1% voltage loss due to wire size. i also aim for the entire circuit to have around 1 tenth of a volt drop or less running a full load.

but i am stingy with my power, i dont like wasting it to heat from small wires and bad connections