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can I use 2 -2S lipo batteries in series to equal a 4S output?

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  • #21
    Originally posted by crankestein View Post

    Aerobob; if you dont understand the above let us know.

    JIC, yes, try to have same make, model (specs), charge/discharge/storage at the same settings as much as possible.
    Dont fall into the habit of using one battery one say for a rc car or another airplane or any electronic device, that uses one battery and then put both in series when going flying.

    Dont tear and wear one more than the other, have those "in series" batteries strictly for series use, NEVER use one alone. That both keep the same cycle of charge discharges. I use them all the time in series on a ARRMA Talion two 3S 4400mah 60-120c and they perform well, connectors, batteries, ESC never over heat (we are talking a esc rated at 180A). Make sure does connectors are solder well, I always apply a coat of E6000 flue over the shrink tubing for extra protection as once in a while when I pull the connectors the shrink tubing slides out, the extra glue helps me have a good grip on them.
    thanks for all you help

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    • #22
      Originally posted by WintrSol View Post
      If mutli-cell batteries are connected in parallel, the individual cells in each pack can be out of balance, if you don't also connect the balance cables between them, so that every cell in one pack is in parallel with its mate(s) in the other. This is often done with a Y cable, so you can keep the cells in balance during both discharge and charge. This used to be more of an issue, but batteries have improved to the point that cells don't often go very far out of balance.
      Still learning with the new jets I have now great fun thank you

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      • #23
        Originally posted by fhhuber View Post
        Can't see a way to put balance between cells in parallel and have it do any good.

        The purpose of balancing is to match 2 or more cells' voltages. Cells that are paralleled WILL match voltage.

        The standard balancing taps are for cells in series. because those can go out of balance. What we are working to prevent with balancing is 2 issues:
        1) Highest voltage cell exceeding the pint where the cell becomes unstable and might (or will ) spontaneously ignite.
        2) lowest voltage cell being discharged to the point that damages the cell.

        There is a chance that a pack will NEVER go so far out of balance that there's danger of either at normal max charge level (which has a little headroom vs what the packs can tolerate if perfectly balanced) and with your LVC set high enough to prevent the low voltage issue. Even without ever balancing. I had some 3S packs that shipped without balance plugs that survived 4 years regular use and died from old age, not any issue indicating imbalance.
        I think Ill stick with a 4S if that is what it is recommended . ,thanks

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        • #24


          Thank you Linda , its sure harder to make your own combination of cells ,I think Ill just stick to what the manufacturer recommends say a 4S 40C 2200mAh battery.

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          • #25
            Originally posted by WintrSol View Post
            Note that the C rating is not changed in either configuration, so your 2S batteries in series would equal one 4S 1300mAh 20C.
            thanks again.:Cool:

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            • #26
              Its better to use two 3S t0 make one 6S, than having a 6S...

              Usually the center cells suffer from excessive heat in comparison to the outside ones which cool much quicker.

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              • #27
                Originally posted by crankestein View Post
                Its better to use two 3S t0 make one 6S, than having a 6S...

                Usually the center cells suffer from excessive heat in comparison to the outside ones which cool much quicker.
                thanks so can it better to use 2 - 2 cell 2200mAh batteries to equal a 4 cell 2200 mAh battery?:Thinking:

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                • #28
                  Yes, it is better, but rare to suffer that much of been enclosed in the battery pack.

                  Although I have seen the heat issue on higher S batteries, 5S or above where the cells are more restricted of airflow/ heat dissipation.

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                  • #29
                    Originally posted by crankestein View Post
                    Yes, it is better, but rare to suffer that much of been enclosed in the battery pack.

                    Although I have seen the heat issue on higher S batteries, 5S or above where the cells are more restricted of airflow/ heat dissipation.
                    thanks still learning

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                    • #30
                      Two new same brand 2S packs may be near identical in individual cell resistance ( IR) and perform nearly the same, in series, as one 4S pack. Two packs connected in a series harness will be slightly heavier due to additional weight of connectors and series harness.
                      Your pack voltage right off the charger will be around 16.8 volts. After takeoff voltage tapers off to around 3.8 volts "nominal" working voltage per cell or 15.2volts. It's best to land when voltage drops to around 15.2 volts ( 3.8 volts per cell) . 3.8 volts per cell is the recommended voltage for long term storage of lipo packs for maximum pack life. It's not good to fly until speed control's low voltage cutoff occurs. Let packs cool completely before recharging also for maximum pack life.

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                      • #31
                        ur welcome, on ARRMAFORUMS, where batteries get a workout, most try to have two instead of one.

                        Some dont like the split in the line, for my style of driving is fine, connectors are slightly warm to the touch, not roasted.

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