Soldering Cells together

I have 6X6 cells, these cells have no tab wiring connected. Here is my question, Using my OHM meter, I get good continuity across the top of each cell when rubbing the white coating off the imbedded tab(x 2) made on the top section of each cell. I don't understand the purpose of soldering additional wire (tabbing) on top of the existing tab? I understand the need to solder on the bottom connections, this makes sense to me, but adding a tab wire on top of the existing circuit I don't understand. Can someone tell me if I can just solder to the edge of the top cells to make my series of connections?

Comments

  • System2
    System2 Posts: 6,290 admin
    Re: Soldering Cells together

    I have read those post and none of them answer my question. What is the purpose of soldering a tab wire on top of what appears to be a solid circuit molded into the cell? I understand the need to connect the bottom of the cell to the top of the adjacent cell, but why not just solder to the edge and not the entire length of the cell? I was hoping someone could shed some light on my question,
  • dwh
    dwh Solar Expert Posts: 1,341 ✭✭✭
    Re: Soldering Cells together

    You'll find that pretty much none of the regulars here are into home-made PV panels - so you might not find anyone who can answer that question with any authority.

    My WAG would be...a way to connect diodes?
  • DeltaFox
    DeltaFox Solar Expert Posts: 27
    Re: Soldering Cells together

    this might help you.

    .http://www.homediysolar.com/index.html

    you have to solder a wire across the hole cell and enough to solder on to the next one.
  • Kamala
    Kamala Solar Expert Posts: 452 ✭✭
    Re: Soldering Cells together

    Seems like a reasonable site. Except for this...

    "I was able to build quality panels as durable and efficient as commercially bought panels."

    I doubt it. Where is the extensive testing for these panels that commercials must go through? 25 year replacement?

    The soldering "tutorial" on the site is good. I learned my soldering technique 30 yrs ago on salvaged equipment. (I've probably done more desoldering than soldering.)

    Which leads me to DIY. The nature of such has changed. Time was, a DIY, (once called a hobbyist,) would have have a "junk box." The items in that junk box were relatively robust. Not necessarily in a physical sense, but in a sense of application. Vacuum tubes were physically fragile but quite simple and forgiving electronically. Transistors, while much more forgiving physically, (impact, vibration and size,) were more sensitive to proper circuit design. Then came ICs. All silicon semiconductors. Which is what PV panels are.

    Few can make a transistor in their garage or basement. And if they could, it would be even more difficult to fabricate a container for it. I believe the same is true for solar cells. Certainly there is no DIY for ICs.

    This forum is hosted by a merchant that sells components that can be used to build a safe and reliable solar energy system. What level DIY?

    As a hobbyist, I encourage all to explore and experiment. Learn theory and technique. And prepare to be disappointed and inspired all at the same instant.

    and then this is offered...

    [FONT=&quot][FONT=&quot]"I would like to thank all the people out there working toward a greener future."[/FONT][/FONT]
  • tallgirl
    tallgirl Solar Expert Posts: 413 ✭✭
    Re: Soldering Cells together
    3blonds wrote: »
    I have 6X6 cells, these cells have no tab wiring connected. Here is my question, Using my OHM meter, I get good continuity across the top of each cell when rubbing the white coating off the imbedded tab(x 2) made on the top section of each cell. I don't understand the purpose of soldering additional wire (tabbing) on top of the existing tab? I understand the need to solder on the bottom connections, this makes sense to me, but adding a tab wire on top of the existing circuit I don't understand. Can someone tell me if I can just solder to the edge of the top cells to make my series of connections?

    No. You want to move as many electrons as you can move from one part of the cell on to the next, or from the previous cell into the current cell. Look at commercially produced cells and you should see what I'm talking about.

    Or you can do as others here have suggested and purchase commercially made panels. Individual cells are great if you're into experimentation. I've made concentrating solar collectors by hand, using unfinished cells, but I wouldn't try making anything I wasn't going to throw away when I was done (which I did).
  • dwh
    dwh Solar Expert Posts: 1,341 ✭✭✭
    Re: Soldering Cells together
    Kamala wrote: »
    The soldering "tutorial" on the site is good. I learned my soldering technique 30 yrs ago on salvaged equipment. (I've probably done more desoldering than soldering.)

    Wow - flash from the past. that made me remember when I used a soldering iron for the first time...I was doing a wood burning in Cub Scouts and my mom didn't want to spend the money for a wood burning tool, so she bought me the cheapest soldering iron from Radio Shack.

    Didn't take me long till I was taking apart a transistor radio. Literally...I unsoldered everything in that radio.

    (Anyone else remember when "Made in Japan" meant the same thing "Made in China" means today?)
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Soldering Cells together

    Remember what "made in the USA" vs "Made in Japan" used to mean vs today? :cry:

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: Soldering Cells together

    i remember, fortunately and unfortunately.:roll::cry:
  • GreenPowerManiac
    GreenPowerManiac Solar Expert Posts: 453 ✭✭✭
    Re: Soldering Cells together

    3Blonds,

    Your question is exactly what I was looking for: The tabbing wire on top (negative side) conducts the electrons into one of two possible flows: Series or Parallel hookups. Typical hookups are in series. The panels can be hooked up into parallel for stacking the amps/current, not the voltage. Back to answering your question now. I've managed to run tabbing wire on only 1/2" to 1" of the white conductive lines on top of the cells and ran underneath to only 2 of the positive tabs in series. The idea is to get enough tabbing wire to make the circuit flow. I have set up 16 solar panels this way and the voltage is 16-20 volts no load per panel. If you wish to PM me, I'll give you my site info to see for yourself. The only question I have is, does this method of tabbing reduce the amount of amps/current flowing through the panel ?
    Nature's Design & Green Energy on FaceBook : Stop by and "Like" us anytime.. Many up-to-date articles about Renewables every day.
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  • GreenPowerManiac
    GreenPowerManiac Solar Expert Posts: 453 ✭✭✭
    Re: Soldering Cells together

    I have found an answer to my own question. Yes, we can use 1/2" to 1" tabbing wire on the negative side and still achieve the same voltage/amperage.

    The reasoning was this: When we use wiring on anything, it must be the proper size rated for the amount of amps put through it. If not large enough gauge, the wire burns up and severs under the excessive load. This would have burned up the tabbing wire on most of my solar panels if it couldn't take the load. We're talking about minimal voltage/amperage per cell. All my panels are still in tact and soldered. I've saved several feet of tabbing wire this way not to mention headaches soldering ALL the tabbing on.
    Nature's Design & Green Energy on FaceBook : Stop by and "Like" us anytime.. Many up-to-date articles about Renewables every day.
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  • DeltaFox
    DeltaFox Solar Expert Posts: 27
    Re: Soldering Cells together

    when the company's cell tabbed cells they are tabbed on the top side also. You get the voltage you want that way also don't you? I never seen that big of tabbing wire thats more like bus wire. Isn't it??
    Do you have pictures of all your panels??
  • GreenPowerManiac
    GreenPowerManiac Solar Expert Posts: 453 ✭✭✭
    Re: Soldering Cells together

    Here is a picture of my example: http://greenanything.yolasite.com/questions-answers.php

    I get the same nominal voltage tabbing this way than the norm, with less soldering, time and materials.

    Also, on the same page is one of my solar collectors. 16-20v no load.
    Nature's Design & Green Energy on FaceBook : Stop by and "Like" us anytime.. Many up-to-date articles about Renewables every day.
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  • DeltaFox
    DeltaFox Solar Expert Posts: 27
    Re: Soldering Cells together

    I like your picture, I must be going crazy because in my mind I was thinking 1/2 to 1" ,I was thinking wide instead of long. I have some 4x4 but I'm going to use metel frame. I also have some 6x6 & 5x5 so I'm going to keep busy.
  • GreenPowerManiac
    GreenPowerManiac Solar Expert Posts: 453 ✭✭✭
    Re: Soldering Cells together

    Tabbing wire is approximately 3" long instead of the 8" norm. Using Bus wire for tabbing wound not only be difficult but a waste of resources. Bus wire is .003 - .005 thicker and twice the width to carry the "Stacked" current to the next string of cells. Remember what I said earlier, thicker the wire, the more current/amps it can carry.

    Also, never solder cells together while drinking strong coffee. I've ruined probably a dozen of these just trying to handle them.
    Nature's Design & Green Energy on FaceBook : Stop by and "Like" us anytime.. Many up-to-date articles about Renewables every day.
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