Keeping it simple.

Lobo · November 2012

Greetings everyone, like all of you we’re at one time I am new to this forum. Having browsed through the forum for a few weeks I haven’t found an answer to a question. I have seen formulas tossed around for this and that, ohms law probably works ... what ever that is, and this old guy just needs some simple recommendations for a charge controller. First, I know what power needs and demands I have. I have five (5) 120 watt 12V (17.6 v from the panels) panels with an optimal output of 6.84 amps each.

I am now looking for a good quality charge controller (not a no-name ebay special that smokes), one that won’t break the bank and prefer a PWM version. Please keep in mind I don’t do formulas (they all look like Chinese hen scratches to me), don’t have a laptop to drag outside to program a CC and wouldn’t understand how to do it anyway, and just want a reliable controller that is plug-n-play (so to speak) that will work. Any suggestions?

Thanks in advance for any suggestions.

Cariboocoot · November 2012

Re: Keeping it simple.

Welcome to the forum.

Well you've made it easy: regular 12 Volt panels with an Imp of 6.84. Now, if this is on a 12 Volt system you multiple the Imp by the number of panels (five) and get a maximum current potential of 34.2. So you need a controller that can handle at least that, or 35 Amps and up. You could "choke" it down to 30 Amps if you're on a tight budget.

So,
Morningstar TriStar 45: http://www.solar-electric.com/trts12vochco.html
Morningstar ProStar 30: http://www.solar-electric.com/ps-30.html (I wouldn't pick that one in this case)
Xantrex C40: http://www.solar-electric.com/c40.html
Xantrex C35: http://www.solar-electric.com/tracc35solch.html

If you haven't got a 12 Volt system you'll have a problem with an uneven number of panels.

Lobo · November 2012

Re: Keeping it simple.

Cariboocoot wrote: »

Welcome to the forum.

Well you've made it easy: regular 12 Volt panels with an Imp of 6.84. Now, if this is on a 12 Volt system you multiple the Imp by the number of panels (five) and get a maximum current potential of 34.2. So you need a controller that can handle at least that, or 35 Amps and up. You could "choke" it down to 30 Amps if you're on a tight budget.

So,
Morningstar TriStar 45: http://www.solar-electric.com/trts12vochco.html
Morningstar ProStar 30: http://www.solar-electric.com/ps-30.html (I wouldn't pick that one in this case)
Xantrex C40: http://www.solar-electric.com/c40.html
Xantrex C35: http://www.solar-electric.com/tracc35solch.html

If you haven't got a 12 Volt system you'll have a problem with an uneven number of panels.

Thank you for the response. The intent is to get a 6th panel (matching) and to keep it 12 volt. Can't see any benefit in wiring panels to 24 volt with such a small array (short of wire sizing). Besides, I am confused enough ;-)

Cariboocoot · November 2012

Re: Keeping it simple.

There are good reasons for going to a 24 Volt system: http://forum.solar-electric.com/showthread.php?15989-Battery-System-Voltages-and-equivalent-power

But you can not run a 24 Volt array on a 12 Volt system without an MPPT type charge controller.

H2SO4_guy · November 2012

Re: Keeping it simple.

I purchased this from NAWS http://www.solar-electric.com/tr60amp12244.html and it will work at 12, 24, or 48 volts. It will also handle up to 60 amps too. Works well for me and it will function as a LVD (Low Voltage Disconnect) if I choose to use in that capacity in the future if I decide to get an MPPT controller instead of it. They are about $200 and don't forget to get the temp sensor. You can save about $50 if you get the 45 amp version. I always tell them I am buying because they have the forum and I vote with my wallet!

Keeping it simple.

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