The Extreme Drain Power Cell description is this: Extreme drain power cell

While the title is this: Extreme Drain Power Cell

To capitalize or not to capitalize?

Names should be capitalized. Descriptions of things should not be. The description is describing what it is, not stating the name, so not capitalizing it would be correct. (This is assuming that "Extreme drain power cell" is the entire description.) Of course, that's a pretty useless description, but that's a different problem.