Flight Battery Pack

balogh wrote:

Ada99 wrote:As well as the small “Vapex” receiver packs, I also use high voltage receivers/servos with an unregulated 2S Lipo.
=Adrian=

Is the voltage of unregulated 2S LiPo not too high for the receiver and servos that typically work at ~6Volts max?

Because of the possibility that the 7.6 Volt output of the 2S may damage the sensitive receiver and servo electronics that are not rated for such (old analog discrete electronics of the 1950's - 1970's without IC's were more tolerant), some form of voltage regulation would be required.

In the past, I used a zener diode and resistor network to provide such simple regulation. Resistor would limit current and a 6.0 V zener would shunt excessive voltage to ground. It worked like a charm on a milliammeter that I used as an ESV - expanded scale voltmeter for my Ace R/C Pulse Commander transmitter. With a new 9 V dry cell battery (an old brick about 1/3rd the size of a 6 V lattern battery), with a new battery it would show full scale. At below 7 volts, it would show 0 V.

The zener is installed backwards to a normal diode. If installed the other way, it acts as a "short". Since it would provide a constant current drain, one would need to calculate what worst case current draw is for the receiver plus servos. But I leave this as an academic consideration, as it is another possibility to be explored, might be OK given the higher capacity of the 2S pack versus NiMh battery packs.

For me, NiMh provides a simpler solution, since I don't fly indoor ultra lightweights.

balogh wrote:

Ada99 wrote:As well as the small “Vapex” receiver packs, I also use high voltage receivers/servos with an unregulated 2S Lipo.

=Adrian=

Is the voltage of unregulated 2S LiPo not too high for the receiver and servos that typically work at ~6Volts max?

Yes - but receivers and servos are available that can cope with 2S lipo. I’m currenlty using Frsky TFR4 4.6g receivers (max 10v), Blue Bird BMS-101HV 4.4g servos (max 8.4v), SD100 4.7g servos (max 9.6v).

=Adrian=

My Radiolink gear is 6vlt max. I found these:
https://www.amazon.com/gp/aw/d/B09WKCBXKK/ref=ox_sc_act_image_1?smid=A2XZ0PQGR3TYBH&psc=1

$6.00 ea @ 11 grams

Ada99 wrote:

balogh wrote:

Ada99 wrote:As well as the small “Vapex” receiver packs, I also use high voltage receivers/servos with an unregulated 2S Lipo.

Is the voltage of unregulated 2S LiPo not too high for the receiver and servos that typically work at ~6Volts max?

Yes - but receivers and servos are available that can cope with 2S lipo. I’m currenlty using Frsky TFR4 4.6g receivers (max 10v), Blue Bird BMS-101HV 4.4g servos (max 8.4v), SD100 4.7g servos (max 9.6v). =Adrian=

This is good to know, Adrian. I have older radios that lack that tolerance. However I have a bit of reluctance in any new R/C investments, seeing that the US FAA is requiring transponder equipment next Fall, above and beyond what other nations are doing. Further discussion would be better a separate thread, but my current sentiments for focus on C/L and F/F.

Your post about new drone rules had me do a search. Wow, how's that boot feel on your neck comrade?

Strange, but in the EU so far the internal combustion engine powered "drones" like my beloved COX powered RC planes are not yet classified in the main C0.....C3 drone classes, that are all electric powered and some need to be equipped with tranponders and gadgetry.

IC engine powered drones are expected to fall in C4 which at the moment has a very loose definition and no transponders are specified as mandatory accessories.

Check whether the FAA rules in the US are equally slack in defining the IC engine powered drones...you may even be pleasantly surprised as I was..

András, so that we do not drift too far off topic, I have moved replies regarding US drone legislation to:
https://www.coxengineforum.com/t17321-faa-proposed-model-aircraft-id-transponders#224326

(Sorry! It was I that started the off-topic drift. )

I’ve had good luck with using these 5 V regulators in a couple of planes now…. I use 2S lipo for main power…. The regulator is small and barely a bump in the wire …soldered directly into the switch harness…

For my small one, I use a Spektrum 300 mAh Life battery pack.