Receiver Battery

[Peter Morris 5Participant @petermorris5]

Having now ‘converted’ my two boats to 2.4Ghz radio (courtsy of MB’s subscription offer), I am unsure whether I need a battery pack to feed the receiver (Planet R6M) or whether just utilising the feed from the Viper ESC is satisfactory (it seems to work OK, at least in the workshop!).  The Planet instruction booklet seems to indicate that a 4.8v battery pack should be used……  Please keep any responses in simple terms, my knowledge of electrics is rather basic!

[Peter Morris 5Participant @petermorris5]

[M. GraffParticipant @m-graff]

I don´t see how it wouldn´t work. A BEC from the speed controller has 5v output to the receiver, and it is considered a better option, as a fully charged 4 cell pack has 6 volts when charged and slowly drops to the nominal voltage of 4,8 volts. The BEC has 5 volts until the cutoff sets in. The major drawback of using a BEC is when you have a lot of servos or other power consumer through the BEC, most of them can´t cope with much more than 3 servos (unstalled).

[Peter Morris 5Participant @petermorris5]

Many thanks for that.  When you say ‘until the cut off sets in’, this happens, presumably, when the 7.2v battery pack drops below a certain voltage? 

[60wattParticipant @60watt]

He was referring to either the thermal (175 c) or the current cutout mechanism within the BEC.

 

[Peter Morris 5Participant @petermorris5]

Thanks for your advice 60 watt – I wish I was as bright as you!!

[Dave MilbournParticipant @davemilbourn48782]

Posted by 60watt on 18/08/2010 17:10:48:

He was referring to either the thermal (175 c) or the current cutout mechanism within the BEC.

 

 Or perhaps the drop-out voltage? All regulators require more volts going into them than you will get as output. There is a point at which the Volts In becomes too low to produce the regulated Volts Out. In most 5v BEC regulators this level is 5.5v; thus the so-called “drop-out voltage” is 0.5v. You’d therefore not get a whole lot of running time if you were to use a 4-cell main battery pack. I’d suggest an absolute minimum supply for a BEC-equipped speed controller would be either 5 cells or a 6v SLA battery.

Dave M

Edited By Dave Milbourn on 19/08/2010 23:20:33

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