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  1. #1
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    Wiring a battery pack to facilitate balanced charging

    I bought this battery pack:
    1x Sanyo Li ion 18650 14 8V 2600mAh Battery Pack with PCM Plug 4Cells to 4S1P X | eBay

    The second lead, rather than being a balanced connector, is just another standard +/- cable.
    I want to be able to charge this correctly so I want to wire in the correct balanced connector.
    I bought this extension to use:
    4S JST XH LiPo Balance Wire Extension Adapter 20cm Red Black Silicone Wire | eBay

    I opened up the battery pack and this is what it looks like:







    What's my process for wiring up the balanced leads?
    Do I have to cut the two yellow wires and remove the PCM to get to the top of the batteries or is there an easier way?
    Democracy is two wolves and a sheep voting on what's for dinner.
    Liberty is a well armed sheep, contesting the vote.

  2. #2
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    there's definitely an easier way

    Use that spare power plug for the +ve and -ve (the outside wires) on the balance plug (by splicing them in and using shrink wrap or tape on the joint), then solder the 1 inside wire to the tabs connecting the serial batteries at the bottom (where there's a blue end and a flat metal end connected together). So that both parallel pairs get balanced, you'll need to join those 2 tabbed bits together with a piece of wire.

    I can't see why that won't work, unless anyone else wants to chime in?

  3. #3
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    I still need to get the final lead wired in; the one that connects the two pairs under the PCM.
    There are two soldered lugs on the side of the PCM (90* off the two yellow leads) labeled B- and B2
    Any chance one of these is the one I need?
    Last edited by roxtar; 12-26-2012 at 10:34 AM.
    Democracy is two wolves and a sheep voting on what's for dinner.
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  4. #4
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    do you have a multimeter?
    yes there is a good chance one of them is your second to last connection
    ...Scun.thorpe, UK

  5. #5
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    Quote Originally Posted by HEY HEY ITS HENDO View Post
    do you have a multimeter?
    yes there is a good chance one of them is your second to last connection
    I have access to one.
    What do I do with it?
    Democracy is two wolves and a sheep voting on what's for dinner.
    Liberty is a well armed sheep, contesting the vote.

  6. #6
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    you can solder in your balance lead onto the PCM
    check voltage between ..+OUTPUT (p+) and either of B-, B2
    it should read the voltage of 1 cell, in the region of 4volts
    ...Scun.thorpe, UK

  7. #7
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    is the covered tab under the leads B3?
    ...Scun.thorpe, UK

  8. #8
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    yes
    Democracy is two wolves and a sheep voting on what's for dinner.
    Liberty is a well armed sheep, contesting the vote.

  9. #9
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    so it probably wires up......
    PCM....................B+, B- ...... B1 ..B2 .. B3
    Balance lead ....red , Black... x1,... x2,... x3
    check the voltages

    B+>B1
    B+>B2
    B+>B3
    B+>B-
    ...Scun.thorpe, UK

  10. #10
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    Quote Originally Posted by HEY HEY ITS HENDO View Post
    so it probably wires up......
    PCM....................B+, B- ...... B1 ..B2 .. B3
    Balance lead ....red , Black... x1,... x2,... x3
    check the voltages

    B+>B1
    B+>B2
    B+>B3
    B+>B-
    And for the electrically illiterate...
    Democracy is two wolves and a sheep voting on what's for dinner.
    Liberty is a well armed sheep, contesting the vote.

  11. #11
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    Quote Originally Posted by HEY HEY ITS HENDO View Post
    so it probably wires up......
    PCM....................B+, B- ...... B1 ..B2 .. B3
    Balance lead ....red , Black... x1,... x2,... x3
    check the voltages

    B+>B1
    B+>B2
    B+>B3
    B+>B-
    ok with a multimeter check the DC voltage between B+ AND B1

    ...Scun.thorpe, UK

  12. #12
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    heres where you solder the balance lead wires
    red and 4 blacks in order
    last black goes to B-

    ...Scun.thorpe, UK

  13. #13
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    ah nuts, I just realised that this was a 4S1P pack. Sorry, I thought it was a 2S2P, just get so used to seeing them.

    Just listen to what HHIH says, he seems to know what he's talking about

  14. #14
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    Awesome, thanks for the help (and the patience for us electro-challenged)
    Democracy is two wolves and a sheep voting on what's for dinner.
    Liberty is a well armed sheep, contesting the vote.

  15. #15
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    OK, soldered it in, went to charge and...

    s**t


    I'm using a Turnigy Accucell-6 charger and when I try to do a balanced charge I get INPUT VOL ERR message. Standard charging worked fine but trying a balanced charge kept giving the same result.
    Turnigy tech support says it could be my plug wiring is wrong.

    Starting with the negative pin on the balanced plug I get 3.8V, 7.6V, 11.4V, &15.2V on the subsequent pins.
    That sounds dead on, doesn't it?
    Democracy is two wolves and a sheep voting on what's for dinner.
    Liberty is a well armed sheep, contesting the vote.

  16. #16
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    yes, and you should get the same readings starting with the red too
    ...Scun.thorpe, UK

  17. #17
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    All's good.
    Turns out I was right. That error message was due to the fact that I was using a 12V-1.5amp power supply which wasn't up to the current demands of the charger. When I dropped the charge rate to 1amp it worked fine and is charging as I type.

    The genius on Hobbykings tech support (supposed expert on Turnigy) claimed that message didn't have anything to do with the power supply (even though the Turnigy manual said otherwise) and had me chasing all kinds of gremlins, including the wiring of the balanced adaptor.

    A search on Hobbykings own forum gave me the right answer.
    Democracy is two wolves and a sheep voting on what's for dinner.
    Liberty is a well armed sheep, contesting the vote.

  18. #18
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    ahh, i croc clip mine to a car battery!
    ...Scun.thorpe, UK

  19. #19
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    crap - wish I had seen this earlier - I have gotten that same error when trying a 1A supply, then went back to my big 5A bench supply, no error, even charging batteries at 6A. I think you need at least 2-3A of current for the charger.

  20. #20
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    Just bought a 12V-5A power supply on fleabay for $10 shipped.
    Democracy is two wolves and a sheep voting on what's for dinner.
    Liberty is a well armed sheep, contesting the vote.

  21. #21
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    I like to be able to switch the polarity or negative lead around when using two packs in series, sometime the negative end of a pack..

  22. #22
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    Quote Originally Posted by SolarCross View Post
    I like to be able to switch the polarity or negative lead around when using two packs in series, sometime the negative end of a pack..
    you're going to need to clarify what you're trying to do - you don't want to switch polarity of the pack if you're plugging it into your light, cause that will either burn stuff up, or trip any reverse current protection.

    are you meaning you want a way to take 2 packs that are in series together and make them parallel without major hassle?

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