[NSRCA-discussion] AAA NimH batterys

[Jerry Budd]

No, that was the year I flew Tony Frackowiak's old Gator 202 with an 
OS140RX.  I didn't have any chance at making the finals due to not 
getting a flight in on the first day (fuel line came off the motor 
while starting up on the first round - timmed out after 3 min, second 
flight it quit just after takeoff - flooded out).  It just wasn't my 
year.

Thx, Jerry

>Jerry wasn't that your Webra setup??
>  Steve Maxwell
>
>
>>  [Original Message]
>>  From: Jerry Budd <jerry at buddengineering.com>
>>  To: NSRCA Mailing List <nsrca-discussion at lists.nsrca.org>
>>  Date: 1/28/2006 4:02:45 AM
>>  Subject: Re: [NSRCA-discussion] AAA NimH batterys
>>
>>  For the 2002 Nats I switched to a AAA 700 mAh NiMH battery pack to
>>  make weight.  While practicing at the Kokomo field I discovered that
>>  the pack was good for about 1-1/2 flights (don't ask me how I know
>>  that!).
>>
>>  Fortunately, I got control back (well - partially) after the 1-1/2
>>  downline snap and was able to coax the plane back onto the ground.
>>  Not fun.
>>
>>  At the post-flight debrief I figured out that the AAA cells simply
>>  had too high of an internal impedance to deliver enough current to
>>  keep the voltage above the receiver/servo cut-off level when all the
>>  servos needed to move at once.  I was using JR 7000 Super Servos for
>>  aileron which went slow/shut off at 4.6V whereas the other JR servos
>>  kept on working down to 4.2V.
>>
>>  Jerry
>>
>>
>>  >Ed is right.  The smaller the cells the higher the internal resistance.
>Run
>>  >them down to 20% remaining capacity and put a heavy load, like 5 Amps on
>>  >them and read the voltage.  You will probably not like what you see.
>>  >
>>  >Jim O
>>  >
>>  >
>>  >----- Original Message -----
>>  >From: "Ed Alt" <ed_alt at hotmail.com>
>>  >To: "NSRCA Mailing List" <nsrca-discussion at lists.nsrca.org>
>>  >Sent: Thursday, January 26, 2006 3:06 PM
>>  >Subject: Re: [NSRCA-discussion] AAA NimH batterys
>>  >
>>  >
>>  >>  Ed:
>>  >>  You might get disappointing results due to the inherently high
>internal
>>  >>  resistance of NiMH.  Going with AAA cella and such a low capacity
>might
>>  >mean
>>  >>  that you don't get as many flights as you expect before a voltage test
>>  >under
>>  >>  load dips below an acceptable value.
>>  >>
>>  >>  Ed
>>  >>  ----- Original Message -----
>>  >>  From: "Ed Miller" <edbon85 at charter.net>
>>  >>  To: "NSRCA Mailing List" <nsrca-discussion at lists.nsrca.org>
>>  >>  Sent: Thursday, January 26, 2006 9:05 AM
>>  >>  Subject: [NSRCA-discussion] AAA NimH batterys
>>  >>
>>  >>
>>  >>  > Is anyone using AAA NimH batteries for a RX pack ??. I am looking at
>>  >>  > Batteries America ( EHYOST ) and they seem to have AAA NimH's in
>720,
>>  >800
>>  >>  > and 900mah ratings. I currently use their 2/3A 5 cell NimH pack at
>>  >1100mah
>>  >>  > and a weight of 3.85 ounces complete with the long lead I have on
>the
>>  >>  > pack.
>>  >>  > Going to their AAA 5 cell pack looks like I can save about an ounce
>or
>>  >so.
>>  >>  > Mah isn't an issue, I can get in excess of 7 to 8 flights on the
>1100mah
>>  >>  > pack I use now before charging so going to 900mah shouldn't be a big
>>  >hit.
>>  >>  > Don't suggest Lithium anything as lighter, want to continue to use
>my
>>  >>  > Alpha
>>  >>  > 4 charger and am not convinced those new batteries are safe.
>>  >  > > Ed M.
>>
>>  --
>>  ___________
>>  Jerry Budd
>>  Budd Engineering
>>  (661) 722-5669 Voice/Fax
>>  (661) 435-0358 Cell Phone
>>  mailto:jerry at buddengineering.com
>>  http://www.buddengineering.com
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>
>
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-- 
___________
Jerry Budd
Budd Engineering
(661) 722-5669 Voice/Fax
(661) 435-0358 Cell Phone
mailto:jerry at buddengineering.com
http://www.buddengineering.com