You decide to use a battery labeled "850 mAh 2S" with a total voltage of 7.4 V. What is the overall energy capacity of the battery?

12580J.

Explanation:

Given the following parameters;

Current, I=850mAh

Time, t=2s

Voltage, V=7.4 V

Energy = Power * Time

Where; Power = Current (I) * Voltage (v)

E = I*V*T

Since, we were given current in ampere-hour, we would use;

Energy (J) = Charge (C) * Voltage (V)

Charge (C) = Current (I) * Time (t)

C = 850*2=1700 coulombs of charge.

Therefore, Energy (J) = Charge (C) * Voltage (V)

Energy = 1700 * 7.4

Energy = 12580J

Hence, the overall energy capacity of the battery is 12580Joules.