[NSRCA-discussion] E-power

[Richard Strickland]

I put a little piece of trim monocote on each of the batteries per
pair--different colors--and since I am somewhat paranoid about the service
life, I've made a simple graph that I mark when each one (set) is used.  I
can keep track of ambient temp. B/4 and after temps, voltage after,
conditions, etc. and of course--usage per set of packs.  I generally have
them set up in a row for use when I get out to the field in the back of the
truck--and if field charging, I just replenish the back of the line.  Also,
if you do the color (or number) scheme--and mark them down, you'll have a
record of where to start using them the next time out--in my case it's
always red, yellow, blue, and gold--so if blue was the last flight, gold is
first up next.  Seems to work OK.  Due to work and other projects, I won't
be doing much this year, but my last few times out last fall I noticed I was
getting some fairly large variations from one flight to another in ending
voltage flying P-07.  Will investigate that further once I get a chance to
get back out there.

RS
  -----Original Message-----
  From: nsrca-discussion-bounces at lists.nsrca.org
[mailto:nsrca-discussion-bounces at lists.nsrca.org]On Behalf Of Dave Reaville
  Sent: Wednesday, April 18, 2007 12:41 PM
  To: NSRCA Mailing List
  Subject: Re: [NSRCA-discussion] E-power


  Hi Rex et al

  Yep sadly this has happen to me as well. Hard lesson when you have a World
Class, multi- FAI Canadian Champion on the sticks trying out your plane and
you inadvertently load up a set of used packs. ARGHHH! (Lets just say it
wasn't one of my best weeks of RC memories and leave it at that.)  Totally
preventable.

  You need a system that provides checks & balances to ensure that you don't
find yourself in this situation as it's hard on batteries, planes and nerves
:-). For a time I was using a method (from Chad Northeast) that had the
leads wrapped together to indicate a charged set. Once unwrapped for use in
the plane they are left that way until they are recharged.  This method
works well for 10S setups and those running separate 5S packs that had both
leads at the same end. It did work well for me but I have since gone to the
new FP F3A pack's that, through weight reduction design, has the leads at
opposite ends of the pack.

  I agree with Don A. that the voltage check is the only real assured way to
confirm pack state. You have to come up with a routine that confirms the
voltage prior to flight. I wrote a K-Factor article years ago on the CATT
process I use before takeoff. Controls, Antenna, Trims, Timer helps me
negate any "issues" with these items once airborne. So I now need to come up
with something that includes the battery state.

  As my canopy is the last thing to go on (switch is inside for that ultra
clean look :-) maybe something simple like ABC for Aircraft - (wing
attachment bolts?), Batteries (both the RX and main pack voltage check)
before Canopy... I don't know for sure but something like that as we humans
need all the help we can get.

  Food for thought,

  Dave

    ----- Original Message -----
    From: Rex LESHER
    To: NSRCA Mailing List
    Sent: Tuesday, April 17, 2007 8:02 PM
    Subject: Re: [NSRCA-discussion] E-power


    Been there, done that...  Most of us have, and won't admit it.. lol
    I finally got two colors of bands to place around the packs...  Green
and Red.  When I get done charging, I place a Green
    band on the battery.  After I fly, I place a Red band around the pack...
I was thinking about how clever I was...  Right up
    until I flew a pack the other day that didn't seem to have much power.
It had a Green band on it!!!  Green means go, right?
    Some dumby got lazy and didn't follow procedure....   New Rule!!!
"ALWAYS CHECK VOLTAGE BEFORE FLIGHT, NO MATTER WHAT."
    I still use the color bands, but now the voltage gets checked anyway!
With multiple packs, it's easy to get confused  which pack is
    which.  Especially when you are preheating the packs in cold weather!  I
got out of the habit of checking the pack voltage because I'm using
    the TP1010 charger, which displays voltage...   Bad habit, if you're not
taking it off the charger and putting it in the plane.
    Just for you Don, MINE DEFINITELY TOOK MORE THAN 5200+.  All I will say
is that the 5300's have more than 5300!
    I'm just wondering which pack you did that to?  lmao

    Rex
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