Solar Generator

System
System Posts: 2,511 admin
in Solar Beginners Corner #1
Hello I am new to the solar world, but I have tried to read and learn as much as I can. I decided that I wanted to build a very portable and compact solar generator. My entire design fits inside of a 27 series marine battery box. I have a 20 watt panel mounted to the outside of the box. Inside I have a Kintex 7amp CC, Genesis 12v 18a/h battery, 300w power inverter. My problem is that when I hooked it all up and put it in great sunlight, I was pulling in about 21 amps. In about 2 min, the CC started smoking, I had luckily put in quick disconnects so I was able to unplug it hopefully before any damage was done. The CC says that it has 22 amp max input, am I too close to the max already with this panel? Do I need a larger CC? Does this happen when you wire something incorrectly? I thought I had everthing thing right, but as I am new to this, I could use some advice!

Thanks
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  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    #2
    Re: Solar Generator

    there is no way a 20w pv is going to push 22a. at best it will be somewhere around 1.5a. you may have wired things up wrongly and it sounds like the controller may have even smoked. there are more reliable controllers out there too so check some of these as an example.
    http://www.solar-electric.com/stpwmchco.html
    xantrex has some low end controllers as well.
    http://www.solar-electric.com/xachco.html
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  • System2
    System2 Posts: 6,290 admin
    #3
    Re: Solar Generator

    I am sorry I didnt mean amps I meant volts... I was pulling 21 volts off of the panel, it says 17.5 max volts but was actually putting out 21. The CC says 22 max volt input. Here is the info from the panel:
    Peak Power: 20 w
    max power voltage: 17.5 v
    max power current: 1.143 a
    Open Circuit Voltage: 22.1 v
    Short Circuit Current: 1.234

    I didnt have any load hooked up to it just charging the battery, could that be the reason - open circuit?
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  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    #4
    Re: Solar Generator

    ok i understand what you mean now. the pv is rated to 22.1voc and the max on the cc is 22v. this is not good and you should get a cc that will work with what you've got. the cc still may have blown, but we can't be sure of this from where we sit.
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  • bmet
    bmet Solar Expert Posts: 630 ✭✭
    #5
    Re: Solar Generator
    bgs179 wrote: »
    In about 2 min, the CC started smoking, I had luckily put in quick disconnects so I was able to unplug it hopefully before any damage was done. Does this happen when you wire something incorrectly? I thought I had everthing thing right, but as I am new to this, I could use some advice!

    Thanks

    Perhaps your small battery WAS shorting 22 Amps into your controller. Usually by the time you smell something the damage is already done. I'd consider that CC dead, since it's measurements can never be trusted again.

    I once fried an electrical outlet modified for a DC light bulb. It happened because I was thinking AC when I should have been wiring for DC. The instant I flipped the switch the battery shorted, and the closest 'fuse' was the electrical outlet with aluminum wiring. The conduit box contained the fire, and since then EVERYTHING gets a proper fast-blow fuse.

    I was a newbie working with RE battery power, and I could have burned my shop down. BTW I did get the wiring right, so now my shop has solar-provided interior lighting.
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  • stephendv
    stephendv Solar Expert Posts: 1,571 ✭✭
    #6
    Re: Solar Generator

    Can't find anything with a web search for "Kintex charge controller" do you have a link to the product specs? 12V is about the lowest voltage battery that anyone in an offgrid setup would want to charge. And a 17V panel with 22V VoC is the lowest voltage solar panel that will charge a 12V battery.... so it seems a bit strange that the charge controller can't handle that panel as any other "12V nominal" panel is going to have a very similar VoC, and that's not even taken temperature effects into account.
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  • System2
    System2 Posts: 6,290 admin
    #7
    Re: Solar Generator

    Once again I see that I was typing faster than I could think... The CC is a Kintrex not a Kintex. I bought it off Amazon.



    http://www.amazon.com/Kintrex-SPC0601-Controller-Digital-Display/dp/B001HWQZNQ/ref=sr_1_1?ie=UTF8&qid=1319457068&sr=8-1
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  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    #8
    Re: Solar Generator

    stephendv,
    i agree that it doesn't make sense as even a linear regulator ic with added transistors for higher current would see a better voltage ability than that. nothing i've seen on the cc adds up properly so i'm concluding it's a cheap piece of junk. further inquiries all point to amazon which has little on it. i just love their idea of a digital display being 3 little leds. even the price tag is a red flag indicator to me that it's junk.

    bgs179,
    buy a real controller so you won't waste your money on stuff that doesn't work or that might damage other components that are in or attached to your system.
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  • System2
    System2 Posts: 6,290 admin
    #9
    Re: Solar Generator

    I think the answer has been found! The 2 pin quick disconnect plugs that I am using, are the prob. If you plug the two plugs together from the CC to the extensions, it changes sides of pos. & neg. so when I hooked it in the battery, it was reverse polarity. So I switched those wires at the battery, and eveything is working good so far.
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  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    #10
    Re: Solar Generator

    i'm glad you got something out of it, but i'd still strive to get a good controller as you don't know how long that $16 regulator will last.
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