Preamble
This is a useful board that provides servo, XBee and nRFnRF24L01+ connectors for an Arduino Nano. It has onboard regulators for 5 V and 3.3 V. A external power supply of up to 12 V can be used, although, I would exercise caution if using a 12V PSU in conjunction with a Chinese cloned Nano, as 12 V at Vin could possibly cause the Nano to blow (12V + NANO VIN = SMOKE! help!). A 9 V 2 A PSU would be recommended.
The current draw, with MG996 (link, mg996r_tower-pro) servos connected, is 500 to 900 mA per servo, 2.5A at stall.
gr33nonline 