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  • #1

    3600 niMH pack life.

    I know a voltspy isn't the best thing to rely on and when that started to looka bit low at the field I tried another guys battery tester and it said "don't fly". This was after three flights. Its a 3600mAh vapextek niMH "raptor pack".
    I've been charging the pack with my delta peak charger and then, if it hasn't been used for a few days I've been leaving it overnight on my wall socket trickle charger (50mA I think).
    So to fly again I charged it with the field charger and 1200 went into it at 2A before it switched.

    It looked a bit low again after 3 flights.

    Now 1200 is only 1/3 of the nominal capacity and maybe I am being misled by a voltspy and a tester that are meant for testing nicad packs. Maybe the volt drop under load with niMH is different?

    I while ago I cycled the pack down to 1v per cell and I think from memory 2800 went in an out of it - it was a figure that seemed "right" anyhow. Of course I will repeat that now and make a note of the numbers.

    What is the correct volts per cell to go down to when cycling sub c nicads, and sub c nimh?

    I might also check the drain onboard the heli with my power meter. I can unplug the devices and see where the the current is going. I guess I could run that in the heli for a flight but I think it only shows the instantaneous amps, not the total maH (its a wattsup meter) but I'm reluctant to have the extra device in the power line during a flight asking to go wrong anyhow!
    www.heli-extreme.co.uk a good club in south Sheffield
    600n pro BeastX Align DFC head bls251, 3xbls451, align gov, 600d, 2in1
    trex500, BeastX DS510 swash, Beast X cutr and carve head DS520 HK3026-1900, Align 425D blades, 5S4200 rev'trix, K&BDD dampers, AR6200
    "450" superframeSTK, align DFC head v2tail, hk22281-8 on 3S 9650w9257gear commander 55A align 325D hitec digitals Tarot ZYX, AR6100e
    MCPX kbdd tail and blades, miniaviation bats

    Dont spend more flying models than it costs to fly for real
    Tags: None
  • #2
    I think you're overdoing it on the charging amps.
    It will usually false peak quite early when you go too high.

    I mostly charged my 3600 (Sanyo cells) at 0.7 mah.

    Perhaps it's simply not filling it up?
    Cheers,
    Rob
    Team Align, Midland Helicopters, Optifuel, Cyclone Blades, Scorpion Motors, Thunder Power, Savox Servos, JR Propo

    | 3D Championship

    Comment

    • #3
      That ampage was for a field top up.
      I charge at 500mA or 1.1a at home. If the charge rate is over 1.0A the charger switches to 50mA trickle, if it is less than 1A it just switches off after peak.
      so the 1.1A switching to 50mA trickle over night should be filling it right up.
      www.heli-extreme.co.uk a good club in south Sheffield
      600n pro BeastX Align DFC head bls251, 3xbls451, align gov, 600d, 2in1
      trex500, BeastX DS510 swash, Beast X cutr and carve head DS520 HK3026-1900, Align 425D blades, 5S4200 rev'trix, K&BDD dampers, AR6200
      "450" superframeSTK, align DFC head v2tail, hk22281-8 on 3S 9650w9257gear commander 55A align 325D hitec digitals Tarot ZYX, AR6100e
      MCPX kbdd tail and blades, miniaviation bats

      Dont spend more flying models than it costs to fly for real

      Comment

      • #4
        Hmm, odd then...
        Either something is wrong on your heli causing a larger than usual amp draw (but you already said there's no binding etc...) or the pack has a fault?

        My 3600 mAh Sanyo cells (one of the best available NiMH cells, along with GP cells) provide much longer performance.

        Cheers,
        Rob
        Team Align, Midland Helicopters, Optifuel, Cyclone Blades, Scorpion Motors, Thunder Power, Savox Servos, JR Propo

        | 3D Championship

        Comment

        • #5
          They do false peek very easy on a fast charge, i found that when I tried to charge mine at above 2 amps, it would raise the pack voltage too quickly, charging at 1 amp it stuffed it to capacity, (GWS delta peek charger and a watts up meter)
          -I don't crash, I just land with enthusiasm.

          A couple of 600n's with stuff on them that makes them fly..
          A 550 fbl with even more stuff on it to make it fly
          And a Mars 470 which needs stuff putting on it to make it fly

          And a DX8 too

          Comment

          • #6
            I charge my Sanyo 1900mAh sub C pack at 1C and I've seen between 1890 and 1920 go back in after a discharge charge cycle.
            I use a pro peak prodigy 2. I think from memory it goes down to 1v per cell before starting to charge.
            Cheers, Lee.
            Proud recipient of an EGS

            Comment

            • #7
              Hooked my wattmeter up to the heli.
              Stood still it draws 160mA, rotating both sticks makes it draw up to 1.2A max. Stalling any one function doesn't seem to pull more than 1.1A. Rapid waggling of collective draws about 1A (moving two servos).
              The voltspy thing is shooting momentarily into the red under load (using my not fully charged spare nicad) but the reading on the wattmeter is not going below 4.8 under load.

              Meanwhile that 3400 nimh pack (after 2 flights on sunday) is discharging on my charger and so far 2600mAH has come out of it at 1A and its still at 4.6v.

              Looks like I don't have a problem other than a voltspy that is pants and that I borrowed another equally pessimistic battery tester. Maybe that tester was set for a 6v pack or something!
              www.heli-extreme.co.uk a good club in south Sheffield
              600n pro BeastX Align DFC head bls251, 3xbls451, align gov, 600d, 2in1
              trex500, BeastX DS510 swash, Beast X cutr and carve head DS520 HK3026-1900, Align 425D blades, 5S4200 rev'trix, K&BDD dampers, AR6200
              "450" superframeSTK, align DFC head v2tail, hk22281-8 on 3S 9650w9257gear commander 55A align 325D hitec digitals Tarot ZYX, AR6100e
              MCPX kbdd tail and blades, miniaviation bats

              Dont spend more flying models than it costs to fly for real

              Comment

              • #8
                My chargere switched at only 400mah whan charging the discharged pack at 1.1A. Although it then trickles at 50mA for the rest of the night it wouldn't be putting the full charge in.
                I charged it overnight at 500mA and 3600 went in, plus the 400 at 1.1A so that 4,200 into the 4300 pack.
                So I expoect the pack to last this evenings session.
                www.heli-extreme.co.uk a good club in south Sheffield
                600n pro BeastX Align DFC head bls251, 3xbls451, align gov, 600d, 2in1
                trex500, BeastX DS510 swash, Beast X cutr and carve head DS520 HK3026-1900, Align 425D blades, 5S4200 rev'trix, K&BDD dampers, AR6200
                "450" superframeSTK, align DFC head v2tail, hk22281-8 on 3S 9650w9257gear commander 55A align 325D hitec digitals Tarot ZYX, AR6100e
                MCPX kbdd tail and blades, miniaviation bats

                Dont spend more flying models than it costs to fly for real

                Comment

                • #9
                  Strangely enough I have just come across a 3700mah vapextec nihm batt in my garage that I'd forgot about, down to 2.v according to my schulze so I've stuffed it on @ 1.5a to see what happens. I'll let you knopw how much goes back in.
                  Velocity 50
                  Synergy N5
                  Fury 55 FBL
                  Trex 700

                  Light travels faster than sound, this is why some people appear bright until you hear them speak....

                  Comment

                  • #10
                    Cycled my 1900 sanyo twice last night.
                    First one was 1 amp discharge and 2 amp charge and put 1797 in.Then did an overnight with a 10 hr cycle (7hrs discharge and 3hrs charge) and put 1893 in.
                    So, slower is better but I have never had an issue with a 1c charge except with AA sized cells where their internal resistance means they get hot and upset.
                    Cheers, Lee.
                    Proud recipient of an EGS

                    Comment

                    • #11
                      Originally posted by Fixxxer View Post
                      Strangely enough I have just come across a 3700mah vapextec nihm batt in my garage that I'd forgot about, down to 2.v according to my schulze so I've stuffed it on @ 1.5a to see what happens. I'll let you knopw how much goes back in.
                      Finshed with 2805 being put back in, need to test it to see how long it holds up as it's been sitting around for at least 18 months.
                      Velocity 50
                      Synergy N5
                      Fury 55 FBL
                      Trex 700

                      Light travels faster than sound, this is why some people appear bright until you hear them speak....

                      Comment

                      • #12
                        Did 7 tanks this evening without a top up charge and its still good for more.
                        so my problems were down to a poor charging regime, and a charger that is on the conservative side with the delta peak switch.
                        www.heli-extreme.co.uk a good club in south Sheffield
                        600n pro BeastX Align DFC head bls251, 3xbls451, align gov, 600d, 2in1
                        trex500, BeastX DS510 swash, Beast X cutr and carve head DS520 HK3026-1900, Align 425D blades, 5S4200 rev'trix, K&BDD dampers, AR6200
                        "450" superframeSTK, align DFC head v2tail, hk22281-8 on 3S 9650w9257gear commander 55A align 325D hitec digitals Tarot ZYX, AR6100e
                        MCPX kbdd tail and blades, miniaviation bats

                        Dont spend more flying models than it costs to fly for real

                        Comment

                        • #13
                          Good to know it's ok
                          Cheers,
                          Rob
                          Team Align, Midland Helicopters, Optifuel, Cyclone Blades, Scorpion Motors, Thunder Power, Savox Servos, JR Propo

                          | 3D Championship

                          Comment

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