The Compass Battery Module uses high-energy Lithium Thionyl Chloride double-D size batteries in a stack of eight with 150° C (302° F), 165° C (329° F), 180° C (356° F) temperature ratings available. The cells are diode protected to prevent reverse power charges, and are protected by a 5 Amp fuse on the power line. The battery pack will run an MWD system for over 150 hours at a standard pulse rate with a Tensor Pulser, and 80 hours with a gamma probe added. With an upgraded Compass Pulser, a battery pack will operate the MWD system for over 450 hours and over 300 hours with an added gamma probe.

The design of the system allows for the addition of a second battery pack that will be activated when the power of the first battery drops to a predetermined level to then activate the power draw on the second battery. This allows the operator to place the batteries in various positions in the MWD tool design. This option allows the users to determine the optimum position of the directional module determined by magnetic spacing requirements. The use of flexible finned intermodule connectors allows multiple design options on the MWD system with the standards being to place the pulser on the bottom (required) and the gamma and directional module located at the optimum positions.