First of all I have to say that I really love the Android system on my HTC Desire. Never had this kind of a great smartphone and operating system on it. I hope and think you all agree. For this moment I can only find and say that there is one minus for this HTC Desire phone. And that is the battery. I search the internet and found several articles about giving your battery more life. Or better saying, make sure the apps are not draining your battery. Here are some tips that worked for me:

1. Try not to have that much of applications running on your Android system. For example install the application "Advanced Task Killer" (free) from the Android Market. Or check you running services on the Android phone itself.
2. Keep the display brightness as low as you can
3. If you use you camera, please kill the camera app after taking a picture!
4. Don't use the phone directly after a full charge or a reboot (turning on). Just wait for 5 minutes!
5. Change your interactive background to a normal non-interactive background
6. Use of Wifi is better then 3G for your battery
7. Install "JuiceDefender" (free app) which will save up your battery a lot. If you can and want to, you can also install "UltimateJuice" (paid).

If you still have problems after these tips, then there is an application avaible called "PowerTutor". This application shows you real time uses of all applications by there CPU, battery use etc. You can even see the average use if you run it for a longer time. Please stop Power Tutor after your done analysing the problem!

I hope this will help a lot of you people to not drain your battery that soon. All for a better Android life :-)