battery back up

I would like to plug 2 1200ma. nimh batteries into a fut. 8 channel pcm reciever. I have read a few places that say this can be done . Any advice
please? It will be powering a aeroworks 29% katana with 8 standard high torque servos.
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Dan,
I'm assuming you intend to connect the packs in parallel, right? ALL the receiver's servo connections for power (battery plus & minus) are connected in parallel, with the plus & minus battery pins on the RX.
In other words, connecting a battery pack can be done on any RX channel.....provided polarity and proper pin connections are noted.
With the relatively cheap prices of 2000+ma/h "AA" cells however, unless you needed a few ounces for model balance with an extra pack, perhaps it would be prudent to simply purchase a larger capacity pack for the Katana.
With anything...a good practice is....fewer components to fail...mean fewer failures...regarding R/C airplanes, that usually equates to fewer "mishaps". <grin>
I also have a problem charging packs in parallel, as the load (internal resistance) between different packs is not the same, and the packs will charge unevenly.
Mike
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ty. for replying Mike but i was looking for a way to get more amps to the reciever by connecting the second battery to an open channel port. I would use seperate charge jacks and switches.

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| In other words, connecting a battery pack can be done on any RX | channel...
Yup. Plug them into any channel. Use a Y connector if you have to.
| With the relatively cheap prices of 2000+ma/h "AA" cells however, | unless you needed a few ounces for model balance with an extra pack, | perhaps it would be prudent to simply purchase a larger capacity | pack for the Katana.
Actually, two packs gives you a nice backup. One pack can fail (they almost always fail open rather than having a cell short out) and you've still got power.
| I also have a problem charging packs in parallel, as the load | (internal resistance) between different packs is not the same, and | the packs will charge unevenly.
Yes -- if you set up your plane with two NiCd/NiMH receiver packs, you'll need to charge them seperately. This means two charge jacks, and two switches.
--
Doug McLaren, snipped-for-privacy@frenzy.com
Never trust anybody whose arm is bigger than your leg.
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I have several large birds set up like this http://www.rcbatteryclinic.com/parallel.html
If you run out of empty ports on the RX plug a "Y" connector into one position, plug the servo into one leg of the "Y" and your switch into the other leg
bob
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ty for the help. now maybe my adrenalin level for it's first flight will be low enough that i'll be able to hang on to the transmitter!
wrote:

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