To reduce battery consumption for Vexduiono I picked up a 9.6v NiMH Battery pack and charger. Many users on the vex forums note that the power jack on the vexplorer receiver is the standard type jack you'll find on r/c racing battery packs.
I finally sprung for a proper soldering station--a weller digital! I shouldn't be melting any pads anymore.
To eliminate battery usage at the transmitter I also picked a normally closed barrel socket and connector. The socket was installed in the transmitter in a similar way to the PPM jack. The wire to the negative terminal of the battery holder was snipped and connected to the sheath of the barrel socket. The ground of the transmitter was connected to the by pass of the socket. I dremelled out another hole on the right side of the transmitter to accommodate the socket. The leads to this plug are connected to the Arduino power rails which is in turn powered by the USB connection.