So many questions, where do I start..

windgate32
windgate32 Registered Users Posts: 8 ✭✭
Hello, first let me thank all of you who post and answer questions. I have been reading until my eyes are about to fall out. But I love the wealth of info. A little history in hopes it will help someone answer my many questions. I began this adventure doing exactley what alot of post say not to do, lol I bought the E-books on solar and wind, and needless to say I am still a bit confused but did gain some info from them. I started by making a small DIY panel and loved it, and I learned a ton from it. I have no exp at electronics at all but I am handy with the hands. I built it from 2"X2" squares, the 36 cells, somewhere around 18v, after that I got a little more confidence and bought 3"X3" cells, same scenario, a little more amps. Then built a bigger using 3"X6". Now I know I have you veterans cringing , lol, but here is more.. I have a Harbor Freight 30 controller, a Harbor Freight inverter 1000w/2000w, I have made my combiner box, I have 2 6V, 210ah, trojan T605 batteries wired in series to make 12V?, I think that is correct, I get the two mixed up. I have hooked up the panels in parallel to keep the voltage the same and to increase the amps thinking that would charge the batteries better. I do not have the panels out all day due to possible theft, etc, but hook them up when I get home from work each day. There is no load on the batteries. But my batteries will not hold any charge higher than about 12.5V. The controller has had them as high as 12.98 but they quickly go back down. One of my questions is this, Is the amout of solar charge I am getting not enough to even get to a complete charge on the batteries? I know the volts are there, when I push the test button it zips up to 18v then shows the batteries half full and goes back to the charge voltage of around 12.6- 12.8.
I have recently bought a coleman wind/solar controller, I have not hooked it up yet. I have a 1700w wind generator that i have not hooked up yet as well. The whole system will be used at a hunting cabin, so I am trying to learn and work the bugs out. The goal is to be off grid for lights, charging cordless tools , a small fridge. I know it will grow, and have no problem with increasing the battery bank and upgrading to "commercial" panels. lol
In fact, here is another question, My system is based on 12V, I am going to buy 2 panels, commercial ones, I was looking and the Kyocera 135w panels. Now I would go bigger but am I incorrect in thinking that the bigger panels would not be good in my case? Being that I am wanting to stay with the 12V system. I know this was a long post, it is my first.. I hope to learn alot more. Thank you in advance for any advice.

Comments

  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: So many questions, where do I start..

    First off, good battery choice! :D
    Second, you really can't tell what kind of power you're getting out of your home-made solar panels, can you? And not having them out during the peak sun hours of the day means you're probably getting zilch in terms of real charging power.
    Third, 12.5 volts resting isn't necessarily wrong for a 12 V system. Normally you bring deep cycle cells up above their nominal voltage, to say 14.4, allow them to absorb for a couple hours, then let them 'float' at 13.8 as long as the panels can hold it. The best way to tell what state your batteries are in is to get a hydrometer and measure every cell's specific gravity. If they are low, charge 'em now before it's too late.

    No doubt someone on this forum knows who really makes this Harbor Freight equipment, and what the specs are on it. I'd have to say it's probably not the best choice.

    Before you go any further, try to determine what your end usage watt/hrs needs will be; that is the basis for designing a system, with always an eye towards making it expandable. BTW, some of your intended use isn't going to 'like' a modified sine wave inverter - specifically charging batteries and running a 'frige - which your unit probably is.

    This could take a while to sort out - be patient!:D
  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: So many questions, where do I start..

    windgate32,
    you already know that you aren't feeding your batteries enough current long enough if you've read enough here. the voltage does have to peak at the max voltage for charging before it can be checked for an at rest voltage to mean anything. bulk charging needs much power and time to get there. my advice to you is to get a substantial charge into the batteries somehow. buy a battery charger and get a small digital multimeter or dmm to be sure the batteries get to the proper voltage to fully charge, but don't let them exceed that voltage and will be somewhere around 14.4v. check with the manufacturer on that voltage to be more specific as some are higher to reach full charge. it may be better if you invested in a 3 stage battery charger so that you can feel better about it charging more properly. if the voltage is settable and can have a battery temperature sensor then that is good.
    also if you've been reading that you know we recommend the charge current to be between 5 and 13% of the battery capacity rating. 2 6v batteries in series rated at 220ah each will be equal to a 12v battery at 220ah. the charge range should be between 11 and 28.6 amps. don't forget that small current charges may only help to maintain a battery from its storage losses and these are roughly 1-2% of capacity. the area between 2 and 5% may charge, but oh so slowly.
    there's nothing wrong that you built those pvs, but doesn't it disappoint you to know that for all of that which you put into them that you won't get the weatherability, longevity, or power that a commercial panel would've given for possibly a small amount more $? they take advantage of those that want to get into solar or wind by selling you on the diy and they know it isn't a good way to go, but they can make it from selling the books. notice that few have 'kits' as that would entail a product that they would have to back up on claims and the rest just don't care as they take the money and run.
  • windgate32
    windgate32 Registered Users Posts: 8 ✭✭
    Re: So many questions, where do I start..

    Thank you all very much for the info. I have just returned to town, I had a slow electric charger on one and it is stable at 6.52. The other one was at 6.40 and charging. I am going to move my setup to the backyard and let it run all day as you said and see the results then . And I am saving for 2 135w Kyocera panels. 8)