I think like many have said, you are best off doing some diagnostics as to what is causing the problem. A task killer will just force close an app, that could easily just re-open, and you don't know which one it is. Look at it this way, if your front door was damaged and you had to slam it to shut it, what would be better? Slam it every day? Or get it repaired, so it doesn't jam?
A task killer is just forcing an application to close, simple as that. But the root of the problem will still exist, and you are just preventing the inevitable.
A few tools to help you do this (I am sure there are hundreds more too, but this will give you a good idea)
- JuicePlotter - This will plot a graph of your battery use. It is best to use it for a cycle of say 24-36 hours to get a good graph. (Note: I wouldn't recommend running this constantly, as it will lag up, as it will continue to plot data consistently until you wipe it/stop it). It will tell you when 3G, WiFI, GPS etc is running. Is something strange happening over night? Why? Is it a sudden drop in battery, or is it a gradual? Is it anymore than how your battery decreases during daily use?
Here is an example graph (taken from the market)
- SpareParts - This will help you identify what is using your battery. You can breakdown Apps, WiFi, 3G, GPS, Screen Wake Up Time, etc etc. A bit like the built in system battery information, but will tell you a bit more.
- TrafficStats - This will help with data. If a particular app is using data overnight, it will naturally use battery. Another good diagnostic tool.
- SystemPanel - (Note: There is a lite version, which will give you some basic info, but the paid version will help much more). This will help identify specifc apps, CPU useage etc etc. Worth paying for imo, as a great app and only