14 years ago
I'm not sure I'd call this a fault of the RX -- I'd call it proper design.
When the RX finds that the voltage has dropped too low, it doesn't know if the voltage is going to come back or if it's going to get worse -- so the safe thing to do is to go into failsafe immediately, as it may never get another chance. If the voltage then comes back, fine, but the RX can't wait, because if the voltage drops further it may not be able to move the servos anymore.
Now, I don't know what voltage this all happens at, and perhaps whatever it is isn't ideal, but I'd argue that this is the proper behavior.
| Another method, of course, is use 6v rx batt.
Or use larger 4 cell packs with appropriately large wires, and make sure your servos don't bind, so that the voltage never drops too low, even if all the servos are moving at the same time. A lot of people trust their plane to packs that are fine during normal flight, but the voltages sag too much when all the servos move at once.
(Using 5 cell packs is OK too -- then the voltage sags _even more_ during high current draw, but it's got a lot more headroom before the voltage gets *too* low.)
As for your gadget, Horizon sells them too for Spektrum RXs --
The problem has been even worse for the Spektrum RXs, as at least some of them don't go into failsafe when the voltage dips -- they reboot, taking several seconds to come back to life once the voltage comes back. Newer versions of the RXs have sped up the reboot process to around a second or less, but even so -- I'd say the real problem is the battery and wiring rather than the RX, though it's nice if the RX can handle the problem better than going to sleep for a while.