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Don't forget about those batteries!

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  • Don't forget about those batteries!

    Hey guys, I just want to throw out "Don't forget about those batteries" while we are shivering in the cold! At least throw a cycle on them just to wake them up. They will thank you come this spring.

  • #2
    Thank You for the reminder. Seams I forget that every year unless I make up a schedule and put it on a calendar.

    Comment


    • #3
      Do you keep them in "storage" voltage? IE, ~3.8v/cell. I have batteries that are coming on 4 years old with a couple hundred cycles on them. I may consider replacing them during next summer but if they still work, I'll just keep going with them. Through the winter, when I fly only skidders on the snow/ice, many of my batteries (and I have over 50 of them , 2s to 6s) just sit there untouched for 6 months or more. I don't cycle them at all during the storage months and when I do take them out and charge them, they work just as good as when I last flew them.
      If you store them at storage charge, I'm not sure you gain anything if you cycle them or not. Batteries can be kept in storage charge for years at room temp or cooler. If you leave them unused at full charge or well below 3.5v/cell for months on end, that's another story. However, having said that, battery owners should do what makes them feel like they did the right thing.

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      • #4
        On the money XV ..........these LiPo's don't develop a memory voltage like old tech Nicads did that needed to be cycled.
        Warbird Charlie
        HSD Skyraider; FlightLine: Sea Fury; FMS 1400: P-40B, P-51, F4U, F6F, T-28, P-40E, 1700 F4U and a Fox glider; Freewing: A-6, P-51; VQ: P-39; Dynam: ME-262, FW-190, Waco; ASM A-26; ESM F7F-3
        Incinerator Loss 16

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        • #5
          I've always bought lower end LiPos so better might do a little better.

          I have found that with LVC set so the packs come out of the plane close to 3.7v/cell, just leave them there for storage.

          Some batteries might not get used for a few months while others are used several recharges a week. it depends on which stuff i am flying.
          TIME seems more important than charge cycles.

          I average 3.5 years and 350 charge cycles under the high load of an EDF (on 20 C packs) with 3 min average flight times using 75% of rated capacity.
          THEN the packs start not being able to handle the full throttle current of the EDF.
          I can still get another year to year and a half of flying planes that get 7 to 10 min average flight times. Maybe another 100 charge cycles.
          After that the packs are losing both current delivery capability and capacity badly enough I tend to drive a nail through them and burn them for disposal.

          Never leave a full charge LiPo in a hot car, especially here in Texas. When the car interior goes above 150F a full LiPo WILL puff and might burn. A discharged LiPo will survive a higher temperature than a full one.

          LiPos are ALWAYS damaged by temperatures above 150F whether it be from being in a hot car or heating due to high current demand with poor cooling.
          FF gliders and rubber power since 1966, CL 1970-1990, RC since 1975.

          current planes from 1/2 oz to 22 lbs

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          • #6
            Thanks for the reminder. I get lazy and forgetful about my batteries during the winter months. I'm going to test them today. Doc

            Comment


            • #7
              Originally posted by xviper View Post
              Do you keep them in "storage" voltage? IE, ~3.8v/cell. I have batteries that are coming on 4 years old with a couple hundred cycles on them. I may consider replacing them during next summer but if they still work, I'll just keep going with them. Through the winter, when I fly only skidders on the snow/ice, many of my batteries (and I have over 50 of them , 2s to 6s) just sit there untouched for 6 months or more. I don't cycle them at all during the storage months and when I do take them out and charge them, they work just as good as when I last flew them.
              If you store them at storage charge, I'm not sure you gain anything if you cycle them or not. Batteries can be kept in storage charge for years at room temp or cooler. If you leave them unused at full charge or well below 3.5v/cell for months on end, that's another story. However, having said that, battery owners should do what makes them feel like they did the right thing.

              I found that that cycling them every other month during the winter keeps the cells better balanced. I also like to know if I have a battery with a issue before flying season starts.

              Comment


              • #8
                I check mine with a cell tester, to see if any have cells that are starting to drift below the storage level; if I find any, I charge them for a while (to about 3.9V on the lowest cell), then use a balancing discharger to reset them. I've had very few exhibit discharge in storage mode, but I think it's worth the trouble.

                Comment


                • #9
                  How can the voltage rise in batteries while in storage? Mine went from 11.7v to 12.2v while in storage for 3 weeks. Never noticed this happening before. Doc

                  Comment


                  • #10
                    Originally posted by doctormike View Post
                    How can the voltage rise in batteries while in storage? Mine went from 11.7v to 12.2v while in storage for 3 weeks. Never noticed this happening before. Doc
                    Wow Doc, I have never heard of that happening.

                    Comment


                    • #11
                      Originally posted by doctormike View Post
                      How can the voltage rise in batteries while in storage? Mine went from 11.7v to 12.2v while in storage for 3 weeks. Never noticed this happening before. Doc

                      Doc, was that across all your batts? Did you use the same measuring device this time as the prior?
                      Did you subject them to a change from a low temp range to a more ambient(room) temp which induces the chemistry to "wake up" and become more active.
                      11.7 equates to a cell average of 3.9 which indicates they really weren't at storage levels.
                      Warbird Charlie
                      HSD Skyraider; FlightLine: Sea Fury; FMS 1400: P-40B, P-51, F4U, F6F, T-28, P-40E, 1700 F4U and a Fox glider; Freewing: A-6, P-51; VQ: P-39; Dynam: ME-262, FW-190, Waco; ASM A-26; ESM F7F-3
                      Incinerator Loss 16

                      Comment


                      • #12
                        There is always some recovery of voltage during the minutes after use, especially if you run it down more than you should. If you've ever run a battery down to say, 3.5v or lower, as measured immediately after landing, then measure again 10 minutes later, you'll see the voltage come back up a bit. However, I've never seen that happen during storage. On the other hand, that's only 0.5 volts across 3 cells. I suppose it could happen if the temperature or humidity changed (or even barometric pressure) during the storage period. In most scientific reporting of chemical data, "STP" is always noted (Standard Temperature and Pressure) or corrected for, so it's important as it can contribute to variations.

                        Comment


                        • #13
                          It did get colder since I storage charged them. I did check them with two different chargers. The batteries varied in voltage. My chargers, now that I checked this, do put my batteries at a higher voltage for storage than they should. I'll see how to adjust this. Thanks for your input. Doc

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                          • #14
                            Some chargers use 3.8V as the storage level, and some as high as 3.9V; my quad charger uses 3.85V. As long as it is in that range, you're probably good.

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                            • #15
                              Thanks, WintrSol. Mine stops at 3.8. I guess that's ok. Doc

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                              • #16
                                Yeah you're good to go

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                                • #17
                                  Hey Y'all, I have been unable to fly over the past 3 weeks and I made the mistake of charging two RT 6s 22.2 volt 35C 6250 mah batteries and these have not been used since then. I would be more comfortable if these were at storage voltage, but my charger won't discharge these at their current high voltage. My dilemma is this, do I not worry about it, do I charge these again when I go out next to fly, or do I find a way to discharge these and recharge when I go out next? Any assistance here would be greatly appreciated. Best, LB
                                  Captain: Got any ideas?
                                  F/O: Actually not.
                                  — Captain Chesley B 'Sully' Sullenberger III and F/O Jeff Skiles—

                                  Comment


                                  • #18
                                    Throw on some ear muffs, put them in your plane, and run 1/2 throttle to get them down. Ive done this on occasion, as it would take a few hours for my charger to get them down to storage. Especially for these larger more expensive packs, I personally would get them to storage instead of waiting it out.

                                    Comment


                                    • #19
                                      Originally posted by Dirty Dee View Post
                                      Throw on some ear muffs, put them in your plane, and run 1/2 throttle to get them down. Ive done this on occasion, as it would take a few hours for my charger to get them down to storage. Especially for these larger more expensive packs, I personally would get them to storage instead of waiting it out.
                                      That's a good way to do it. Put the battery checker on it while you do this so you know when to quit. Anything around 3.8 to 3.9v per cell ought to be good for peace of mind. However, having said this, I had a flying buddy who used to charge his batteries as soon as he got home from the field and left them that way till he flew again. He had batteries that were kept like that for a good part of a season and they seemed to perform just as well when he did finally use them, although we don't know what effect this had on the longevity (number of cycles lost) of these batteries. When he passed away and the batteries went to his friends, they all seemed to work OK.

                                      Comment


                                      • #20
                                        Originally posted by xviper View Post
                                        That's a good way to do it. Put the battery checker on it while you do this so you know when to quit. Anything around 3.8 to 3.9v per cell ought to be good for peace of mind. However, having said this, I had a flying buddy who used to charge his batteries as soon as he got home from the field and left them that way till he flew again. He had batteries that were kept like that for a good part of a season and they seemed to perform just as well when he did finally use them, although we don't know what effect this had on the longevity (number of cycles lost) of these batteries. When he passed away and the batteries went to his friends, they all seemed to work OK.
                                        At 1/4 to 1/2 throttle the starboard ESC was running at 129`F and port is running 114`F. I ran the motors 1/4 to 1/2 throttle as per DD with the battery checker as per xviper. Starboard motor flame-out at 8+ minutes with battery temps at 128F +/- each. ESC temps were 107F+/- each. Thanks for the assist, gentlemen. Best, LB
                                        Captain: Got any ideas?
                                        F/O: Actually not.
                                        — Captain Chesley B 'Sully' Sullenberger III and F/O Jeff Skiles—

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