Tried this out yesterday, just used one of the preconfigured battery level scripts.

It seems to work nice but later that night when I went to go charge my phone it would not charge. I noticed the widget meter did not match the phones icon in the status bar for battery level.

I started to worry my usb port was broken. Turning off the widget and rebooting the phone fixed it and it charged. I never had this problem before and this was my only new application so atleast a decent chance that the widget/script somehow lead to the phone not going into charge mode.