Know before you go, that the channel you are on is clear of other transmitters and interferrence. Check both the transmitter and receiver while monitoring battery pack voltage/capacity.

BATgraph is a very accurate and repeatable ESV Expanded Scale Voltmeter.  

The voltmeter is adjustable from 2.5 to 25 volts (2-18 recharge cell packs)  for each cell added to the pack, the volts, per led light, increases automatically at a rate of ( charged = 1.3 volts and discharged 1.1 volts giving a nominal span of  .2 volts per cell.  This eliminates multiple adjustments to increase span of the meter as the voltage is increased to  monitor higher voltage packs.  The simplicity of adjustment makes it easy to use with almost any battery.  With a fully charged pack, adjust the meter to turn on the last green LED.  Order for the number of cells in your pack and type of battery, the  ESV will come pre-calibrated and tested!  If you want the calibration changed, see our change document or return the unit to our factory.  

DeBug has an additional pulse" sniffing" circuit that continuously checks the pulse-train from the transmitter thru the receiver to the servos.  Missing pulses lock the display into the bar mode (all LED's ON).  This will show problems in the transmitter, receiver, antennas or wiring harness.  You can the high gain receiver, without your transmitter turned on to "sniff" the air waves. To detect interference that may also crash you.  Turn on the receiver, without the transmitter, and it should immediately go to the (bar) mode (all LED's ON). If it hesitates, suspect interference especially if your servos are jerking around.