any merit in running dual battery packs ?

[J.Oddino]

Hi Urs,
I like the 18650 cells that are in the 2000 to 2400 mAh range now.  These are the cylindrical cells with metal cans like Central Hobbies sells.  I believe they are more rugged than the Li-Poly cells and one doesn't need to worry about taking them out of the plane to charge.  I use the Jaccio Perfect Switch Harness but I'm biased because I make them.
Regards, Jim
  ----- Original Message ----- 
  From: Bärtschiger Urs 
  To: discussion at nsrca.org 
  Sent: Saturday, January 29, 2005 2:12 AM
  Subject: Re: any merit in running dual battery packs ?


  Hi Jim,

  Fully agree with your statements. 
  Questions: 
  - Which capacity Li-Ion battery are you recommending for a pattern plane equipped with digitals?
  - Which solid state failsafe voltage regulator switch harness do you consider suitable?

  Thanks for your comments.

  Urs 
  NSRCA # 3069

    ----- Original Message ----- 
    From: J.Oddino 
    To: discussion at nsrca.org 
    Sent: Friday, January 28, 2005 8:14 PM
    Subject: Re: any merit in running dual battery packs ?


    Two packs and two switch harnesses are good from the standpoint of eliminating single point failures and they would minimize voltage drops between the battery and receiver buss as the current in each would be cut in half thereby reducing the voltage drop by a factor of two.  The down side is the added weight and cost.  I'm using two in my third scale plane but have stuck with single packs in my pattern size planes.  If you go with one battery and one switch I'd recommend a solid state failsafe voltage regulator type switch harness and a Li-Ion pack.  The higher capacity of Li-Ion takes care of the added current we see with the digitals and the higher voltage allows better regulation at a higher voltage resulting in more servo torque and speed (more power).  With the voltage regulator you don't need to worry about voltage drops between the battery and the buss.
    Jim
      ----- Original Message ----- 
      From: Hitesh Gajjar 
      To: discussion at nsrca.org 
      Sent: Monday, January 24, 2005 4:13 AM
      Subject: any merit in running dual battery packs ?


      Hi,

      Now that we all using high powered digital servo's with incredible holding power etc - is there any merit in running 2 battery packs, say 1 Ah each as opposed to 1 high capacity pack thereby eliminating the single point failure ? If I did want to run 2 packs, is a diode necessary to prevent 1 pack from possibly charging the other if 1 pack were to go bad ?

      Cheers,
      Hitesh
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