My Esc says it has a BEC capacity of 3 Amps. Its a R/C Timer brand 40 amp ESC. At what voltage is this BEC going to supply and can it be used to power the flight pack also. I have a 2650 Mah 3 cell Lipo. Will the voltage be too high for a Jr receiver and servos?

The sole purpose of the BEC (Battery Eliminator Circuit) is to regulate the voltage of your flight battery to a level that is correct for your receiver and servos. BECs provide somewhere between 4.8V and 6V, usually 5V.

Connect your components as shown in the diagram below. The voltage for the receiver and servos goes to the receiver through the red (center) wire on the 3-pin connector plugged into your receiver's throttle channel.

The BEC (Battery Eliminator Circuit) is so-called because it Eliminates the need to carry a separate battery to provide power for the receiver and servos.

- Jeff

Thanks JD for the info on the ESC/BEC question. I've been flying Glow powered planes since 1970 and this is my first foray into the electric part of the hobby. I may ask a few more stupid questions, but I'm very thankful theres guys like you out there that will help newcomers to electric flight. Thanks again, this has helped me tremendously. Harold , AKA Kamakazi

See chapeter 15 on BECs
http://www.rcuniverse.com/forum/m_7100376/tm.htm