Does having the battery indicator on drain more battery?

It will probably rob you of 0.5 seconds of battery life.

It'd be ironic, wouldn't it...but seriously, so will just about anything, and this will probably drain the battery less than opening an app. Honestly, its kinda ridiculous to worry about something like this.

How bout you try it, then let us know.

nope

its just reporting the visual battery icon as a number

its reporting something that already exists in the iPhone Ram, not a new process