After purchasing most of my multirotor parts from my friend (see First parts), all I need to get flying is a battery charger, transmitter and receiver. I looked around for awhile and finally decided on the FlySky TH-9X transmitter for its relatively low cost and large number of channels (9 channels).
As for the charger, I had several 50 watt chargers recommended to me, but after doing some math decided that I needed at least an 80 watt charger. Here’s why:
The batteries I will be charging have an average voltage output of 11.1 (3-cells each at 3.7 volts) volts over their discharge period, but are charged at 14.48 volts (this is due to the electrochemistry behind the reverse reaction in the lithium-polymer battery). It is a general rule to charge your batteries at an amperage equal to the capacity of the battery. For example, my batteries are 3,300mAh (milliamp hours) or 3.3Ah (amp hours) so I would charge them at 3.3 amps. This means that my charger must have an overall power output of 3.3 amps x 14.48 volts = 47.784 watts. This is below 50 watts so a 50 watt charger would be able to handle this, but if I would like to charge my batteries at a higher amperage once in awhile for a faster charge time or purchase batteries with a higher voltage or capacity, a 50 watt charger will not be able to supply enough power (the charger automatically limits the current delivered to remain within its power rating (watts) while keeping the voltage at the correct level for the voltage and chemistry type of the battery being charged). Therefore I selected a charger with an 80 watt rating, specifically the Thunder AC680 for its relatively low price, built in power supply (transformer) and good selection of adapters. The reason I did not select a higher wattage charger is that chargers become considerably more expensive once they go over the 100 watt power rating and they require a separate external DC power supply, increasing the cost further.