i have a 6 volt pack 2000 mah pack that i used all day yesturday, and when i checked my battery before my final flight, the voltage readout would give me about 5.4 which i know is too low to safely fly on a 6 volt battery if im not mistaken...and under a load it would drop to 1.5 volts...why? and just right now i checked again and the voltage would drop to 1.5 under a load..... im using the hobbico mk3 voltmeter