SparkFun Lithium Ion Battery 2200mAh 7.4V - 2-Cell Pack programmer which is enough for multiple

which is enough for multiple servo motors and current-hungry boards like GSM modules

Push Button Shield&nbsp

The Skeleton Box is a handy solution

it has a DFU bootloader (we unplugged/replugged it from USB to kick off the DFU process)

and a wide range of frequency tuning

SparkFun Lithium Ion Battery 2200mAh 7.4V - 2-Cell Pack programmer which is enough for multiple7. 4V Li Ion Battery 2200mAh (2S) The Lithium Ion Battery 7. 4V 2200mAh is a higher capacity 2S pack for robotics, camera gimbals, and portable power applications that need 7. 4V with longer runtime. Technical specifications Chemistry Lithium Ion Configuration 2S Voltage 7. 4V nominal Capacity 2200 mAh