Last week I ran into some very interesting problem with my laptop battery. Usually battery for my Dell Latitude E6500 lasts for about 4 hours as long as I am not watching movies or doing any graphic intensive stuff. One morning while I was travelling, I noticed that my battery was showing battery life down to 75% with in 20 minutes of starting my laptop. And I noticed that it was loosing life very fast. Battery that used to last 4 hours was showing that it will end in just over an hour.
I was puzzled because there was no hardware or software change that I had done. And I have not touched my power settings in over a year. So I started my diagnostics my looking at power settings. Everything was set to normal power save mode etc. To be sure I customized to dim the screen etc. I pretty much shutdown all the services that i did not need at that very moment. Nothing helped. My battery drained in an hour.
Next morning same thing. Battery was draining fast. I decided to close some of the applications that keep running to reboot the system. When I tried to close Microsoft Outlook, warning message popped up telling me that there is an email that is waiting to send. I did not think much about it and closed the application. After rebooting laptop i started outlook to see what email was stuck. I found that there was n outgoing email where I was trying to send a MP4 file to somebody. It was over 70MB file. no matter what I tried, the email will not go though. And on top of that, when I tried to remove that outgoing email, Outlook will not let me do it because it was getting caught in a loop of resend operation. So to remove this email, i disconnected my laptop from network and then managed to delete this email from Outlook.
Right after I deleted this email and connected laptop to network, there were no more warning messages from Outlook. And battery was behaving normal again. It seems that whatever it was, not only Outlook was trying to send the MP4 file but it probably was trying to play it in some preview mode of something as well. And that kept draining the battery.
Never thought that an issue with Outlook could affect battery life like this.