[NSRCA-discussion] Lithium Ion batteries

[Robert & Casey Green]

Thanks Eric, great info!
  ----- Original Message ----- 
  From: Grow Pattern 
  To: NSRCA Mailing List 
  Sent: Thursday, November 30, 2006 7:06 PM
  Subject: Re: [NSRCA-discussion] Lithium Ion batteries


  Robert,
              I would like to pass on that 7.4V Li-Poly's can drive a regulator much harder than a two cell Li-ion. By "drive" I mean overheat  the regulator to the point of temporary failure. I found out (the hard way) that certain regulators will drop the voltage to 3V or less when they get hot.  If they cool down soon enough you get the plane back, if not you crash. Then you are puzzled by the fact that it all still works. been there?

  Lipo's seem to be able to deliver the higher current for much longer than the Li-ions when under load.

  I found this out when I switched to Li-poly's for flight packs a couple of years ago. A regulator that was working perfectly well before I swapped packs (Li-ion to Li-Poly) gave me fits during a couple of flights. I lost the "solid link" and got erratic results from my flight inputs. I knew it was not failsafe because the plane kept trying to roll on its own. My failsafe were tested and gave level flight with low throttle.

  I was like I was getting low battery failsafe, nothing, then control then a roll condition and then low throttle again, then nothing again. This lasted several minutes while I coaxed the plane around to a landing. It happened twice on one plane and once on another.

  On the ground you could see the ailerons not centering properly and the regulator was too hot to touch.. Switching it off allowed the regulator to cool down and then it all worked again.

  The good news is that you can test for the potential problem very easily without flying the plane. Switch on for about 5 minutes. If you get any heat on your regulator when you switch to a Li-poly stop there. By heat I mean that it is clearly hot to the touch!

  I switched brands and found out that the Oddino regulators and Batteries of America 5.2V (red brick type) regulators all do the job just fine with a 2-cell Li-Poly.

  I have had some mysterious radio problems over the years that I now attribute to transient voltage loss due to heat build up in the regulators. 

  Just passing it on,

  Regards,

  Eric.



  From: Robert & Casey Green 
    To: NSRCA Mailing List 
    Sent: Thursday, November 30, 2006 3:35 PM
    Subject: Re: [NSRCA-discussion] Lithium Ion batteries


    Thanks for the feedback.  Had an Eclipse about three years ago, go into complete lock up and soon as it took off.  I turned left and the plane never came out of the turn; did I mention that this was it's inagural flight.  Had duralites on-board, and since then I have been a little gun shy about them.  Could there haev been othe factors besides the batteries, sure; but I have been wary of using those batteries again.
      ----- Original Message ----- 
      From: Cameron Smith 
      To: 'NSRCA Mailing List' 
      Sent: Thursday, November 30, 2006 7:35 AM
      Subject: Re: [NSRCA-discussion] Lithium Ion batteries


      Duralite needs the business.

       

       I personally know of a judgment awarded RECENTLY due to there DEFECTIVE Batteries/Chargers. (They had some serious ISSUES when first releasing there Li-Ion. Products.)

       

       There are a few more responsible Li-ion suppliers out there. 

       

       If Lithium technology is the direction you would like to go I would recommend Li-Polys. & JimO Regulators!

       

       

      If any further information is needed about Duralites & there legal issues contact me OFFline.

       

       

       

       

       

      -----Original Message-----
      From: nsrca-discussion-bounces at lists.nsrca.org [mailto:nsrca-discussion-bounces at lists.nsrca.org] On Behalf Of Robert & Casey Green
      Sent: Wednesday, November 29, 2006 8:43 PM
      To: NSRCA Mailing List
      Subject: [NSRCA-discussion] Lithium Ion batteries

       

      Hey Guys, I am thiking about running lithium-ions batteries this year.  Besides duralite, is there anything else worth using.

       

      Thanks in advance.

       

      Robert



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