Recalibrate battery......desire s

[NaNaNiii]

I've been thinking of recalibrating battery on my HTC Desire S to improve the battery life as some people have suggested however, i have a few queries. Has anyone actually managed to get a longer battery life on the desire by recalibrating? Also, is there any danger of me messing the phone up and does it invalidate the warranty?

[happy_highlander]

Have you ever flashed the phone, if not then there is no need to calibrate the battery