Battery charge thresholds error? (Battery maintenance in Power Manager 2)

[nmabakhsh]

Power Manager 2 version 2.43 (W500, Vista Business 32bit)

In battery --> battery maintenance --> charge thresholds

I've got it set to custom (start charging when below 15%, stop charging at 100%).

But once it reaches 100%, it stays there and doesn't discharge at all. Unless I unplug the power cord, and then plug it back in when its under 15%. If I plug it in before it goes under 15%, then the percentage freezes, doesn't charge or discharge. Which sucks for when I have to go mobile...

Is something wrong? What is the point of the custom feature if I have to unplug it at 100, and replug it only when its below 15%?

What are the best thresholds to set for maximum battery life?

Can I just charge the battery to 100%, then remove the battery and use the power cord at my desk? How long will the battery remain at 100% when stored?

Hope someone can help...