[bradart]

Ok. I'll provide some clarity as to why this happens.

When an app is meant to be an ongoing process (like monitoring the battery) it is required to be at the forefront of the cpu. If it isn't it will get closed and you won't have accurate data, if any at all. The only way, thus far, to make absolutely sure that an app doesn't get closed by the cpu scheduler is to place an ongoing notification in the taskbar. If the cpu gets a heavy load, it's thought process is as follows:

"Yo, dog, these apps are getting heavy as hell. I should probably get rid of some of them. Ok, i haven't used this one in a while." *drop* "What about this one? nope, haven't used it in a while either" *drop* "And THIS o---oh crap, it has a notification. That must mean that i need it. I'll keep that one."

As you can tell by my arbitrary illustration, the notification icon lets the cpu know that "Hey bro, i'm using that. All. The. Time."

On a related note, if you install a new battery guage from the market, you are just ADDING AN EXTRA. It does not and cannot replace the original battery icon. This is because the battery icon that comes built into android is....built into android. The only way to modify or get rid of it is to have root permissions and change the files related to it (Which is incredibly possible, by the way. XDA has tons of resources on it). When you get a battery monitor app from the market, you are simply ADDING another battery monitor, not affecting the original. I hope this helps.