If your running 4 regular sized servos (40-50oz) in a sport plane, you will need a 4 cell 4.8 volt 600 - 700 mil amp Nicad battery. you will need a 50 to 60 mil amp wall charger. This is a standard pack that comes with most radios and is available at any hobby shop for under $20. Spectrum uses JR connectors which are compatable with Hitec and Airtronics as well. Dont forget an on/off switch with charge lead as well. there is so much bad information out there about batteries, so be careful.