I use SB Settings, it works perfeclty, i think, it never changes back unless i touch the icon.
HEREs the Weird thing!, Obviously my iPhone 3g was jailbroken and i have SB settings, i always have the numeric batery that way i can monitor better my batt.., so, I Restore the phone cause it was a little laggy and I wanted to upgrade to 2.2.1 (dont know why hehe) and when i restore the phone, it keeps the numeric batery and it changes if i touch the batt icon, like if the phone was jailbroken but it wasnt, i was kinda weird if you ask me, why would that happend? i dont know, i use the phone UN-Jailbroken for 2 days and the numeric battery works hehe, anyways then i RE-Jailbreak it!!😀