Well i've been testing it for a day or two now and it seems to be fine. Its still annoying that the battery reading is rarely correct, its the same sort of problem I had on my T-Mobile G1 android phone, but at least there 3rd party apps could be relied on for an accurate reading. All the 3rd party apps I have tried from the apple store all give different readings.
I've tried I-battery free (which I then paid for and its still wrong), App box pro (seems to be the most accurate of them all) and system which is also wrong. Can anyone suggest a good accurate battery app?