Lipo Question/help

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  • hkusp45
    Senior Member
    • Jun 2007
    • 299

    #31
    Originally posted by wickedgmc
    I appreciate the help

    I did and always balance my cells with a hyperion LBA10 while I charge them.
    I changed the voltage cutoff to 13.2 for a 4 cell set up
    I use the ICE charger and has been good so far I have a hyperion charger on the way as well so I can charge the big 6 cell pack

    I am hoping a change to parallel will save the life of my batteries and my DPR (thanks SJFE) just got here so now I will know whats going on in the boat.


    thanks

    That is all very good equipment!! I was not knocking anything just tryin to solve the problem......

    Please let us know if you get it sorted
    NAMBA #581
    Q mono NAMBA record holder
    'REMEMBER SOME PEOPLE ARE ALIVE SIMPLY BECAUSE IT IS ILLEGAL TO SHOOT THEM'

    Comment

    • Diegoboy
      Administrator
      • Mar 2007
      • 7244

      #32
      I believe SJFE is correct. The "C" rating will be additive.
      "A quick temper will make a fool of you soon enough."
      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Bruce Lee. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

      Comment

      • Diegoboy
        Administrator
        • Mar 2007
        • 7244

        #33
        RC Hobbies .org

        RCUniverse
        "A quick temper will make a fool of you soon enough."
        . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Bruce Lee. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

        Comment

        • JimClark
          Fast Electric Addict!
          • Apr 2007
          • 5907

          #34
          Not trur there are a lot of Thunder Power cells and also PolyRC cells being used in racing

          Originally posted by SJFE
          It seems the guys who race use the Neu power cells.
          "Our society strives to avoid any possibility of offending anyone except God.
          Billy Graham

          Comment

          • NorthernBoater
            Senior Member
            • Apr 2007
            • 811

            #35
            The c is not additive:
            - 3s1p with a rating of 2400 mah and 10c will deliver 28.8 amps continuously.
            - Those same packs in a 3s2p will have a total capacity of 4800 mah and will be able to deliver 57.6 amps continuously.
            - If the c was additive then that 3s2p pack would be able to deliver 115.4 amps. Half of the current is 57.6 amps which is more than one pack can deliver. You will end up with blown cells if you do this.

            Comment

            • SJFE
              Fast Electric Addict!
              • Apr 2007
              • 4735

              #36
              Not trur there are a lot of Thunder Power cells and also PolyRC cells being used in racing
              I ment to say "seem to use". I type faster than I think some of the time.

              Wait a minute....I did say seem to use..it's not like I said..Oh they ALL use them bar none. jeez
              Last edited by SJFE; 08-25-2007, 08:28 PM. Reason: HOLD ON A MINUTE

              Comment

              • Diegoboy
                Administrator
                • Mar 2007
                • 7244

                #37
                Originally posted by NorthernBoater
                The c is not additive:
                - 3s1p with a rating of 2400 mah and 10c will deliver 28.8 amps continuously.
                - Those same packs in a 3s2p will have a total capacity of 4800 mah and will be able to deliver 57.6 amps continuously.
                - If the c was additive then that 3s2p pack would be able to deliver 115.4 amps. Half of the current is 57.6 amps which is more than one pack can deliver. You will end up with blown cells if you do this.
                Unless I'm reading all this wrong, You are incorrect sir.

                RC Groups...

                ...but what do I know? I'm just googling it and posting the results I read. It's just funny that all the results I have read are contradicting the general consensus. Can you show me proof of your theory? I'd like to see it.

                Just to be sure, is the "C" equal to mAh? I might be wrong if that is not true.
                "A quick temper will make a fool of you soon enough."
                . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Bruce Lee. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

                Comment

                • Flying Scotsman
                  Fast Electric Adict!
                  • Jun 2007
                  • 5190

                  #38
                  Originally posted by NorthernBoater
                  The c is not additive:
                  - 3s1p with a rating of 2400 mah and 10c will deliver 28.8 amps continuously.
                  - Those same packs in a 3s2p will have a total capacity of 4800 mah and will be able to deliver 57.6 amps continuously.
                  - If the c was additive then that 3s2p pack would be able to deliver 115.4 amps. Half of the current is 57.6 amps which is more than one pack can deliver. You will end up with blown cells if you do this.
                  3s1P 2400 mah 10C will deliver 24 amps @ 20C will deliver 48 amps 2p will deliver 96 amps @ 20C, all continuous figures
                  2S1P 5000 mah 25C will deliver 125 amps continuous and 7.4V
                  2S2p 5000 mah 25c will deliver 250 amps continuous
                  2 2S1P 5000 MAH in series will deliver 125 amps and 14.8V

                  Doug

                  Comment

                  • Diegoboy
                    Administrator
                    • Mar 2007
                    • 7244

                    #39
                    Originally posted by Flying Scotsman
                    3s1P 2400 mah 10C will deliver 24 amps @ 20C will deliver 48 amps 2p will deliver 96 amps @ 20C, all continuous figures
                    2S1P 5000 mah 25C will deliver 125 amps continuous and 7.4V
                    2S2p 5000 mah 25c will deliver 250 amps continuous
                    2 2S1P 5000 MAH in series will deliver 125 amps and 14.8V

                    Doug
                    Doug,
                    Layman's terms please, SJFE is right? or not?
                    Last edited by Diegoboy; 08-25-2007, 08:46 PM.
                    "A quick temper will make a fool of you soon enough."
                    . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Bruce Lee. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

                    Comment

                    • wickedgmc
                      Senior Member
                      • Jun 2007
                      • 719

                      #40
                      Originally posted by hkusp45
                      That is all very good equipment!! I was not knocking anything just tryin to solve the problem......

                      Please let us know if you get it sorted
                      did not taking anything negative, sometimes the answer is right in front of you and someone has to ask you the question for you to find the answer.

                      Comment

                      • NorthernBoater
                        Senior Member
                        • Apr 2007
                        • 811

                        #41
                        When you parallel you double your capacity not your c rating. There is no way to double your c rating!

                        Comment

                        • Flying Scotsman
                          Fast Electric Adict!
                          • Jun 2007
                          • 5190

                          #42
                          Originally posted by Diegoboy
                          Doug,
                          Laymens terms please, SJFE is right? or not?
                          OK

                          C refers to the discharge rate eg a 1000mah 10c battery is rated at 10 amps. 1000mah 20c is rated at 20 amps all lipo batteries are rated to deliver a short 10 seconds or so higher amp rate typically 30C on a 20C continuous rated battery
                          Therefore multiply your MAH figure By the C rate eg 1000mah 20C ....2.0 X10 = 20 amps.
                          When you parallel 2 2S1P 1000 mah 20C batteries = 40 amps @ 7.4V
                          In series 2 2s1P 1000mah 20C batteries = 20 amps @ 14.8V

                          I trust this makes sense.

                          Doug

                          Comment

                          • Diegoboy
                            Administrator
                            • Mar 2007
                            • 7244

                            #43
                            More googling found this...

                            "For example, two 1,000 mAh Lithium Polymer cells with 15C continuous discharge ratings that were wired in parallel would create one 3.7 V pack with a 2,000 mAh capacity and could support an application where the total current draw was up to 30C (30 Amps). "

                            Link <-- Pulled directly from a lipo battery website!!

                            Again, it contradicts. Please show your sources for your info.
                            "A quick temper will make a fool of you soon enough."
                            . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Bruce Lee. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

                            Comment

                            • Diegoboy
                              Administrator
                              • Mar 2007
                              • 7244

                              #44
                              I think that was the KO punch to this debate...


                              LOL
                              "A quick temper will make a fool of you soon enough."
                              . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Bruce Lee. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

                              Comment

                              • SJFE
                                Fast Electric Addict!
                                • Apr 2007
                                • 4735

                                #45
                                Well I can't argue with that data. Screw it I'm ordeing them. I'll take one for the team here.

                                Comment

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