R921 RX powered from BEC or battery pack

[FLAME747]

Hi Guys,

Just got an X9503, with a R921 receiver, I plan on installing this on my Trex 450 sport, But do I power it from the BEC or must I use a separate battery pack

Thanks,

FCA

[Ah Clem]

First of all, I do not know if the R921 draws any more current than the AR6100 or AR6200, so I do not know if that is relevant (the R921 vs. any other receiver).

I believe that the BEC contained in the Align 35X ESC is only rated at two amps.

While I have only heard of one complaint about low current problems (a buddy of mine said his servos slowed down), two amps was not enough of a safety margin for me.

I have a Castle BEC (the small blue one) which, if memory serves, is rated at 10 amps on three cells (far more than the servo plug that it uses to power the receiver is rated at).

I have about 70 flights on the machine (Trex 450 Pro), so far.

I think, realistically, if it were a real problem, you would see lots of posts complaining about brown outs on the Trex 450 Pro and Sport. I don't think I have seen any, so far.

[FLAME747]

Have the R921 hookup up to my heli, trying to setup my helicommand, plugged in a fully charged 2600mah pack, no flying or spooling of the motor, the lights on the main & sat rx starts blinking after 8 Minutes - Pack shows 11.52 volts

Correct me if I am wrong but - flashing lights means low voltage right

[FLAME747]

lights blinking on main & sat receivers ???

[Ah Clem]

That does sound like a "Brown out".

How much current does the Helicommand draw?

[FLAME747]

Per the manual 4-6 volts, current drain 55Ma {at 5V}

I have the stock Trex 450 Sport setup with 35A BEC.

I am using 2600 mah & 2200 mah 3s zippy packs

Thanks,

FCA