Best battery choice? + Current Draw used per flight

[JOddino]

Brian,
Each servo draws about 2 amps when it starts and 3 when it stops.  These are
very short pulses.  However, when you are sitting there vibrating you are
continuously starting and stopping all your servos.  The real test is to get
a measure of what the average current is in flight.  Then base your battery
capacity requirements on that.
One approach to minimize current is to get servos with larger deadband.
Jim
----- Original Message -----
From: "Brian Young" <b4598070 at yahoo.com>
To: <discussion at nsrca.org>
Sent: Monday, April 14, 2003 6:09 AM
Subject: RE: Best battery choice? + Current Draw used per flight


> I found I wasnt getting the capacity I thought I
> should w/ my 1800 mah 6 cell flight pack. After two
> masters sequences I recharged and put back in 600mah
> (triton charger), pack was topped up prior to flight.
>
> So back home, I put a current meter between the
> battery and receiver. I draw about 90 mA with all
> servos connected, each servo unplugged the total drops
> by 15 mA, except for the throttle which drops 10 mA.
> Wiggle the sticks and I can occasionally get over 300
> mah. This didnt seem unusual to me, anyone disagree?
>
> So I left the meter in place and started the plane, at
> idle the meter was reading 3 Amps, yep 3. Has anyone
> else done this?
>
> I move the trottle off idle a little and the current
> drops to about 2-2.5 Amps, so my throttle servo is
> bottoming a bit.
>
> 3 Amps in this gauge wire seems like it should be
> getting something hot, but I hooked the multimeter up
> in series with my battery just like I learned in
> school.
>
> The servos are all digital JRs with over one season
> use, except I did replace the Aileron servos w/ new
> yesterday but havent had a chance to repeat my test.
> All thoughts on what could be causing this are
> appreciated. Otherwise a 4000 mah flight pack is
> looking good to me. Is there any reason a worn servo
> would draw more current?
>
>
> Thanks.,
>
> --- Dean Pappas <d.pappas at kodeos.com> wrote:
> > There are plenty of us nicad stalwarts!
> > Mark, I agree with your reliability/convenience
> > assessment.
> > My 5-cell SR 1000 mAH is good for better than 5
> > flights, as I have
> > repeatedly measured the consumption of a
> > all-digitals practice flight at 145 mAH.
> > I'm considering going to a 500 pack and after every
> > flight top-ups with the Sirius.
> > That gets the weight to the point where any
> > disadvantage to the nicad is, in my opinion,
> > greatly outweighed by their reliability.
> >
> > Dean pappas
> >
> > -----Original Message-----
> > From: Atwood, Mark [mailto:atwoodm at paragon-inc.com]
> > Sent: Friday, April 11, 2003 10:22 AM
> > To: discussion at nsrca.org
> > Subject: RE: Best battery choice?
> >
> >
> > Lol....ok Anthony...then there's two of us flying
> > Nicads.  I use some of the newer technologies for my
> > electrics, but with regard to Pattern, the new
> > batteries appear to fix problems I don't have.  I
> > run a 5cell 6v 1400mah nicad pack.  I personally
> > haven't heard an argument that even comes close to
> > making me want to change.
> > Cost/reliability/convenience all seem to favor
> > Nicads.  The only one against it is weight.  And
> > from my perspective, if I need that ounce...I have
> > bigger problems.   Just my .02...I'd love to hear
> > others opinions on the subject...
> >
> > mark
> >
> >  -----Original Message-----
> > From: AAbdu at aol.com [mailto:AAbdu at aol.com]
> > Sent: Friday, April 11, 2003 10:00 AM
> > To: discussion at nsrca.org
> > Subject: Best battery choice?
> >
> > It seems like every month a new battery technology
> > is introduced. NiMh, Lithium ion, NiCad etc. Each
> > one claiming to be better than the last. It seems
> > like I am the last pattern flyer still using old
> > familiar, heavy, memory burdoned NiCads. I am
> > considering investing in updated batteries and all
> > of the other things needed to maintain them. I have
> > accepted that I will need not only the battery, but
> > a new charger, regulator, and all the other fixins.
> > Given that condition, what is the latest info pro
> > and con on the new battery technology. I know there
> > was an availability issue with the duralites that
> > has seemed to be resolved, then I remembered hearing
> > something about them overheating or blowing up or
> > spontaneously combusting or something. My point is,
> > there is a lot of misinformation out there and I am
> > trying to find out what works best from those who
> > use it.
> > In order of importance of features:
> > 1. Reliability
> > 2. Weight (lighter is better)
> > 3. Capacity, can I get 5 flights on them, can they
> > be quick  charged?
> > 4. Durability / margin of error / expected life
> > span. If I leave the RX on do I have to replace
> > them?
> > 5. Price
> > 6. Availibility
> >
> > I appreciate any information you guys can provide.
> > Thank you.
> > Anthony
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>
> =====
> Brian Young
> Tulsa
> b4598070 at yahoo.com
> 918-745-6046h
> 918-838-0900w
>
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