Your phone needs to be rooted in order to follow this tutorial. I researched build.prop settings recently and learned how to increase battery life and performance. I use Root Explorer to edit build.prop in place, it makes a backup before saving changes. Please read this entire post before making any modifications. 1) Make a nandroid backup before making any changes 2) Seriously, make a nandroid backup 3) Download Root Explorer from the market 4) Launch Root explorer and go to /system 5) Make sure /system is mounted as R/W, this info and a button are at the top of the Root Explorer screen 6) Long-press the build.prop file and choose "Open in Text Editor" 7) Add the following settings or tweak them if they're already present (notice the "or"?) 8) Once edited press Menu > Save, Root Explorer will save a backup of the original file 9) Reboot 10) Any problems should be fixable via Root Explorer 11) If the phone fails to boot simply restore a nandroid backup Code (Text): # Force launcher into memory ro.HOME_APP_ADJ=1 # Start at a lower heap size and increase as needed dalvik.vm.startheapsize=8m # VM Heapsize; the higher the RAM, the higher the heap can be dalvik.vm.heapsize=32m # Render UI through GPU instead of CPU # Comment out if this causes laggy UI debug.sf.hw=1 # Time between wifi scans in seconds. Keep it high to minimize battery drain # 5 minutes=300, 4 minutes=240, 3 minutes=180, etc. wifi.supplicant_scan_interval = 300 # Allow power collapse, increases battery life ro.ril.disable.power.collapse=0 # Puts the CPU into deep sleep but preserves registers pm.sleep_mode=2 # Net speed tweaks, choose what you need net.tcp.buffersize.default=4096,87380,256960,4096,16384,256960 net.tcp.buffersize.wifi=4096,87380,256960,4096,16384,256960 net.tcp.buffersize.wimax = 4096,221184,524288,4096,16384,110208 net.tcp.buffersize.umts=4096,87380,256960,4096,16384,256960 net.tcp.buffersize.gprs=4096,87380,256960,4096,16384,256960 net.tcp.buffersize.edge=4096,87380,256960,4096,16384,256960 # When moving through zones or losing signal, having a delay # smooths out constant disconnects and reconnects, saves battery life ro.mot.eri.losalert.delay=1000 I made these changes on my Evo 4G yesterday on the rooted stock ROM and on CM7. I haven't seen any problems and battery life seems to have increased a bit. I'm sure there are other tweaks but I haven't researched all of them yet. Anyone who has more tweaks feel free to post a reply.