new guy: Wire gauge

hamr49 · July 2011

Two questions on wire size.
1. What is the correct Wire gauge to run from the my battery bank, into my
morning star, prostar charge controller? I have 4 150amp batteries.
2. What is the correct wire guage to run from my solar charger to my inverter?

Thanks

Cariboocoot · July 2011

Re: new guy: Wire gauge

hamr49 wrote: »

Two questions on wire size.
1. What is the correct Wire gauge to run from the my battery bank, into my
morning star, prostar charge controller? I have 4 150amp batteries.
2. What is the correct wire guage to run from my solar charger to my inverter?

Thanks

Well it's ask questions and toss out references time!

First question: four 150 Amp hour batteries configured at what Voltage?
Second question: Distances on wires (array to controller and controller to batteries)?
Third question: How much PV have you got and how is it configured?
Fourth question: Which MS Prostar are you using?

You see it all matters: the Voltages involved, the current expected, and the distances between one point and another.
For a bit of self-help, take a look at this Voltage drop calculator: www.solar-guppy.com/forum/download/voltage_drop_calculator.zip
And another useful reference is this wire gauge table: http://www.powerstream.com/Wire_Size.htm

There will probably be more questions later.

hamr49 · July 2011

Re: new guy: Wire gauge

1. Batteries are configured for 12 volts.
2. 25 feet from array to controller. 6 feet from controller to battery bank
3. 2 panels, each panel is 130 watts, 7.56A, 17.2V.
4. Using a ProStar PS 30 PWM CHARGE Controller.

Thanks for help, this is all new to me.

Cariboocoot wrote: »

Well it's ask questions and toss out references time!

First question: four 150 Amp hour batteries configured at what Voltage?
Second question: Distances on wires (array to controller and controller to batteries)?
Third question: How much PV have you got and how is it configured?
Fourth question: Which MS Prostar are you using?

You see it all matters: the Voltages involved, the current expected, and the distances between one point and another.
For a bit of self-help, take a look at this Voltage drop calculator: www.solar-guppy.com/forum/download/voltage_drop_calculator.zip
And another useful reference is this wire gauge table: http://www.powerstream.com/Wire_Size.htm

There will probably be more questions later.

Cariboocoot · July 2011

Re: new guy: Wire gauge

hamr49 wrote: »

1. Batteries are configured for 12 volts.
2. 25 feet from array to controller. 6 feet from controller to battery bank
3. 2 panels, each panel is 130 watts, 7.56A, 17.2V.
4. Using a ProStar PS 30 PWM CHARGE Controller.

Thanks for help, this is all new to me.

Well I said there'd be more questions.

These batteries: four 150 Amp hour 12 Volt batteries all in parallel? Or are they 6 Volt 150 Amp hours wired for 300 Amp hours @ 12 Volts total?

I see a problem arising with only 260 Watts of panel, which would support 150 Amp hours @ 12 Volts, but certainly not 600 Amp hours @ 12 Volts.

So far it looks like 8 - 10 AWG from panels to controller and 10 - 12 AWG from controller to batteries.
But that is not a precise calculation.

hamr49 · July 2011

Re: new guy: Wire gauge

4, 150Amp hour batteries wired in parallel, 12 volts, 600 amps.

Are you suggesting i cut my battery bank down to 1 or 2 of the 12v, 150Amph
batteries?
Thanks

Cariboocoot wrote: »

Well I said there'd be more questions.
These batteries: four 150 Amp hour 12 Volt batteries all in parallel? Or are they 6 Volt 150 Amp hours wired for 300 Amp hours @ 12 Volts total?

I see a problem arising with only 260 Watts of panel, which would support 150 Amp hours @ 12 Volts, but certainly not 600 Amp hours @ 12 Volts.

So far it looks like 8 - 10 AWG from panels to controller and 10 - 12 AWG from controller to batteries.
But that is not a precise calculation.

Cariboocoot · July 2011

Re: new guy: Wire gauge

hamr49 wrote: »

4, 150Amp hour batteries wired in parallel, 12 volts, 600 amps.

Are you suggesting i cut my battery bank down to 1 or 2 of the 12v, 150Amph
batteries?
Thanks

Either that or greatly increase your panels. Here's a little piece on deep cycle batteries: http://www.windsun.com/Batteries/Battery_FAQ.htm
There's also some difficulty with keeping current shared properly with four batteries in parallel. Here's a guide about connecting up multiple batteries: http://www.smartgauge.co.uk/batt_con.html

600 Amp hours would want 60 Amps @ 14.4 Volts (assuming FLA's). That would "max out" a big controller like an FM60. It would also need quite a bit of panel: about 1122 Watts worth. Are you sure you need the approximately 3600 Watt hours that battery bank would supply? That's 1.5 times what I run the cabin on. If you do need that much power, you should think about going to a 24 Volt system: it will reduce quite a number of problems with wiring and current handling. But you'd still need a lot more panel.

bmet · July 2011

Re: new guy: Wire gauge

Consider a marine battery switch. At least you could keep a pair alternately charged, and then combine them for supply side.

Cariboocoot wrote: »

Either that or greatly increase your panels. Here's a little piece on deep cycle batteries: http://www.windsun.com/Batteries/Battery_FAQ.htm
There's also some difficulty with keeping current shared properly with four batteries in parallel. Here's a guide about connecting up multiple batteries: http://www.smartgauge.co.uk/batt_con.html

600 Amp hours would want 60 Amps @ 14.4 Volts (assuming FLA's). That would "max out" a big controller like an FM60. It would also need quite a bit of panel: about 1122 Watts worth. Are you sure you need the approximately 3600 Watt hours that battery bank would supply? That's 1.5 times what I run the cabin on. If you do need that much power, you should think about going to a 24 Volt system: it will reduce quite a number of problems with wiring and current handling. But you'd still need a lot more panel.

new guy: Wire gauge

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