Needless to say, we would be grounded without a power source to enable us move under the water. We would all love a weightless, costless power source which we can easily tuck into a corner and not be bothered about maintenance costs. Nuclear power is definitely a favorite for underwater power but unfortunately Uranium is way too expensive. So are radio isotopes and fuel cells. A closed cycle combustion engine is an attractive choice but it has its downs too, especially the risks associated with it when running manned systems. A careful examination of available sources easily pinpoints the convenience of battery power. We settled on Lead acid batteries, the accepted norm of power for submarines of our scale. Though definitely with their fair share of disadvantages, storage batteries are our best bet given our power requirements and the costs involved. It then all boils down to how many batteries we'll use and their arrangement.

We have divided our power requirements into primary, secondary and auxiliary / emergency requirements. For each we intend to use a different set of batteries, as they all require varying amounts of power.

The items falling under these classifications and the expected power consumption are:

a) Primary:
Thrusters, ballast system (ballast pumps), external lighting and cameras and lights, the Hydraulic System and the robot Arm
Total: 36 kWh
This would require 10 x 12V Batteries with a charge of 300 Amp-hours.

b)Secondary:
Internal lighting, life support systems, computer system, and the communication system.
Total: 3.6 kWh.
This would require 3 x 12V Batteries with a charge of 100 Amp-hours.

c)Auxiliary/emergency requirements
The emergency system should be able to support communication system and Emergency interior lighting and life Support systems for an extended period depending on the rescue procedures in place. A reasonable estimate for this system would be 1.2 kWh . This would require 1x12V battery with a charge of 100 Amp-hours.