Thanks for the advice. What I thought was if the battery got charged too often its life will be shortened.

I have a E71 which has incredible battery life. I usually charge it every 3 or 4 days. Sometimes the battery dies before I charge it. Have been using E71 for over a peroid of a year, the battery still seems as good as when I brought it. Even when my E71's battery dies, it only takes about a few seconds to pick up the charge - I can turn on the phone almost instantly.