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    Maximize Lipo Battery Life Cycle

    Hi,

    If you like to maximize the life cycle of your Lipo batteries, the following are my
    humble suggestions for your reference.

    1. Set your charger so that the max charging voltage per cell is 4.18V instead of 4.2V.

    2. Don't charge your Lipo batteries more than 1C if you can. In any case, not more than 1.5C.

    3. Never charge your Lipo batteries without balancing. Check to see if all cells are balanced
    at the end of charging.

    4. Don't do parallel charging.

    5. Check the balance cables/boards of your charger regularly. Connection problem of the
    balance cables/boards can cause the charger to miss read the cell voltage and over charge one
    or more cells. Best practice is to set your charger to display the individual cell voltage once you
    connect a battery to the charger. Check that the voltage of all cells are okay and make sense
    before you start charging.

    6. Don't over discharge your batteries. Not lower than 3.75V per cell.
    The cell is as good as gone if it is lower than 3.2V.

    7. Storage charge is around 3.8V to 3.9V per cell.

    8. Allow a battery to cool down after a discharge before you charge it again. My opinion is to
    wait for two hours (to allow the middle cells to cool down) before you charge it again.


    Not all points are listed here. Some are common sense.

    I saw someone charging battery at the field using his car and a small charger.
    The car engine was running, the charger input was connected to the car battery,
    and .... the lipo battery was placed on top of the radiator during charging.
    I didn't believe my eyes.

    #2
    Someone asked why set the full charge voltage to 4.18V instead of 4.2V.
    The electronics components in the charger and the cables will cause errors in voltage reading by the charger.
    The total error can be as much as 0.015V to 0.02V per cell. So, if you set the full charge voltage to 4.2V, the charger
    may charge a cell to beyond 4.2V. This will damage and deteriorate the cell. It may also cause the cell to bloat.

    Comment


      #3
      4.18v for me....advised by Pang of heliguru many many moons ago
      Heli-ADDICTION:
      Mikado Logos, RaptorG4s, X7F, 600ESP...
      JUST one more Logo...for the month.

      Comment


        #4
        It is important to know the reason behind why certain things are done that way.
        If you don't know the reason behind and don't know the consequences, it is not likely you
        will do it diligently.


        I like to share two cases of lipo battery charging "abuse".

        Case 1:
        Someone came to see me for help. His batteries could not last, short life cycle.
        I did a quick check of his batteries. The cells' voltages are quite wide apart in all
        his batteries. It turns out that he charged all his batteries without balancing by not
        connecting the balance connector to the charger, as advised by his good brother.
        In this case, there is no way for the charger to know the voltage of each cell.
        So, some cells will be charged well beyond 4.2V and damaged.
        I am surprise that none of his battery ever caught fire while charging. Lucky him.
        Please note that charging a lipo beyond 4.2V can cause fire.


        Case 2:
        A friend told me he never bother if the battery cells are balanced after charged.
        He simply set the charger timer to one hour, charger stop after one hour.
        He doesn't care if the cells are balanced.
        One fine day, some cells were dead after a flight. The batteries are well within 100 cycles.
        Those cells really worked to death, poor thing. I could feel their pain.

        Comment


          #5
          Lesson learnt
          1. Buy good batteries
          2. Buy good charger
          3. Do not over discharge, when the timer sounds, land and dun act smart and fly for another 30 seconds.
          4. Use telemetry to tell how much is juice is used and land at preset %
          Too many helis!

          Comment


            #6
            Originally posted by nb8686 View Post
            It is important to know the reason behind why certain things are done that way.
            If you don't know the reason behind and don't know the consequences, it is not likely you
            will do it diligently.
            i tried to understand...my head hurts after reading the content page of electronics 101...rather be focusing on the high amps of yuma or sunny...OOPS!
            Heli-ADDICTION:
            Mikado Logos, RaptorG4s, X7F, 600ESP...
            JUST one more Logo...for the month.

            Comment


              #7
              Type of Lipo Chargers

              Type 1 Charger:
              This is the common and conventional charger. It charges the lipo cells in series through the thick discharge cable. The charger balance the cells by discharging the cells with higher voltage. Each cell has a discharging circuit which allow individual cell to be discharged when the charger is doing the balancing act. In short, when the charger is charging it needs to charge all the cells at the same time, and when it is doing the balancing, it will have to discharge the selective cells.
              After some cycles of usage, lipo cells will not behave exactly the same; some cells will charge faster than others. The best lipo batteries money can buy will not be exempted from this. For those cells that charge faster than others, they will have to be discharged so that all cells can be balanced.
              Over a number of cycles, the these cells will deteriorate faster than other cells. And the problem will get worse and worse as the battery continue with such charger. You will also notice that the balancing seem to take forever. Performance of the battery will get bad very fast.


              Type 2 Charger:
              I call this cell charger. This kind of charger charges each cell independently to full charge voltage. For a 6 cell charger, it will have 6 individual charging circuit. There are two kind of such charger; one is fixed charging current and voltage (you cannot change any setting), the other is programmable cell charger where you can change the charging current, full charge voltage, etc. I don't recommend the use of the fixed cell charger, as this kind of chargers are generally not accurate. Anyway, a cell charger do not need to do any balancing as it charge each cell to the full voltage. The setback of this kind of charger is, it cannot charge at high current as it charges the battery through the balance wires. Usually the max current is about 2.5A or slightly more. In other word, the charging time is long especially for larger capacity batteries. The good thing about cell charger is it will not deteriorate any cells.



              In order to take better care of lipo batteries, I use the Type 1 charger to charge my lipo batteries until a point when one or more of the cells are close to the full voltage.
              I then use the Type 2 charger to continue to charge the lipo until all cells reach the full voltage. In this way, there is no discharge action on any cell, and so there is no discharge deterioration on all cells.

              Of course, this process is troublesome. But it is good for the lipo batteries.



              Now, the Type 3 Charger:
              Recently, a new type of charger (Type 3) emerged. This kind of charger is a hybrid of Type 1 and 2. In the first stage of charging, it behaves like a Type 1 charger. When any of the cells reaches the full charge voltage, the charger behaves like Type 2 charger. In summary, this kind of charger has the following pros:

              A. The charging time is the same or faster than the conventional chargers.
              B. These is no balancing discharge, so no cell deterioration.
              C. The balancing time is short as it only involve charging, no discharging. This also reduce overall charging time.

              Comment


                #8
                My "charging station". Which includes three hybrid chargers, one conventional charger and one cell charger. LOL.

                This station is able to charge 10 pieces of 6S 5200mAh Lipo batteries in one hour with no high charging rate, and without parallel charge.


                Attached Files

                Comment


                  #9
                  Originally posted by nb8686 View Post
                  My "charging station". Which includes three hybrid chargers, one conventional charger and one cell charger. LOL.

                  This station is able to charge 10 pieces of 6S 5200mAh Lipo batteries in one hour with no high charging rate, and without parallel charge.


                  My Salute to Pro flyer! Really appreciated for sharing your pro experience with us.

                  Comment


                    #10
                    Originally posted by river001 View Post
                    My Salute to Pro flyer! Really appreciated for sharing your pro experience with us.
                    Thanks

                    Comment


                      #11
                      hi,

                      may I know which is your hybrid charger, which is your conventional and which is your on cell charger?
                      i'm interested in Safe Charger, having experience a lipo going up in flame at home.
                      At the same time, worried about overprice charger, again having experience with a German brand charger that went bad after I attempt to charge a 1s 450mah lipo for mcpx. Warranty cost as much as a new charger from other country of origin.

                      Comment


                        #12
                        Originally posted by mave View Post
                        hi,

                        may I know which is your hybrid charger, which is your conventional and which is your on cell charger?
                        i'm interested in Safe Charger, having experience a lipo going up in flame at home.
                        At the same time, worried about overprice charger, again having experience with a German brand charger that went bad after I attempt to charge a 1s 450mah lipo for mcpx. Warranty cost as much as a new charger from other country of origin.

                        There is only one hybrid charger in the market for now.
                        You can get this locally: http://rc.zenmtech.com/charger-radio...l-charger.html




                        For the cell charger, I use the UnA9 Plus.
                        Zenmtech is a rc company base in Singapore. Our product range include rc helicopter, multicopter, spare parts, esc, bec, lipo battery, etc. We are Align, JR, Zolta distributor in Singapore.




                        For the conventional charger, I use the Hyperion EOS 0720i Super DUO3.
                        This charger is no longer in production. I think there is a new model.
                        If you get the hybrid charger, you don't need the conventional or the cell charger anymore.


                        I am not sure if there are any safe chargers available, at least not 100% safe.
                        To be safe, you have to be near to the chargers when you charge your batteries.

                        I do have bad experience with German chargers too some years ago.
                        S$800+ a piece, I bought one at first, then when it failed, I bought another.
                        I sent the first charger all the way back to Germany for repair. It failed again within
                        one month after the repair. The second one failed a few months later.
                        I gave up. LOL.

                        The problem of both chargers was due to over heating. I could smell the plastic burning
                        inside the chargers. I believe it was using the old technology. New chargers are using
                        pulse (PWM) charging, so much less heat generated inside the charger.

                        For example, the cell charger I mentioned (CP620), the inside temperature is less than
                        35 degree C.

                        New chargers are relatively inexpensive these days, it is not worth to repair.
                        Attached Files

                        Comment


                          #13
                          nb8686,

                          so far, how do you feel about the hybrid charger? have you push it so far, i.e. what the max you have charge with it?
                          i have six pairs of 6s for my 1/8 EP onroad. They do take sometime to charge on the Hyperion duo net.
                          So, I am thinking of an extra charger to reduce the charging time.

                          Comment


                            #14
                            Originally posted by mave View Post
                            nb8686,

                            so far, how do you feel about the hybrid charger? have you push it so far, i.e. what the max you have charge with it?
                            i have six pairs of 6s for my 1/8 EP onroad. They do take sometime to charge on the Hyperion duo net.
                            So, I am thinking of an extra charger to reduce the charging time.
                            I have been using the three hybrid chargers for a month now. So far I have charged about 240 pieces of 6S 5200mAh batteries;
                            i.e. about 80 batteries per charger. I am quite happy with the chargers. I am going to stop using the conventional and cell chargers.
                            I only need the hybrid chargers.

                            I don't think I really push the hybrid chargers. The rated max charging power is 750W, and max charging current is 30A.
                            My main charging current is set at 8A, and cell charging current set at 2.5A.

                            I use only 60C 6S 5200mAh batteries.

                            I want to maximize the life of my batteries, so I don't want to push the charging to the limit of the charger.
                            Trying to maintain at about 1.5C charging rate. Batteries are more "expensive" than charger over certain quantity.

                            Comment


                              #15
                              Today, the following pair of batteries (with the charging care I mentioned in this thread) has reached its 200 cycles.



                              Slightly bloated, but I have not noticed any drop in flight time. They still give 5 minutes of flight time (soft 3D only).
                              I use them on a Trex 700X with headspeed of 2060.
                              The landed voltage is about 3.78V per cell. I will continue to use them. I like to see how many cycles they will last.
                              Attached Files

                              Comment

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