rtc ds1307 - all value goto 255

can't work this out... i finished soldering everything onto a board for one of my loggers (18x 3 channel datalogger)
it has 1 24lc256 on it as well
what gets me is why after i set the time then remove the power ... the rtc doesn't have a backup battery so i know it's supposed to clear but instead when i powered it up again after the initial time setting bit is done all the values just say 255
is the rtc not really good for on/off apps or does it have to have a backup battery
it will reset and work properly after about 5 mins though but i'm wondering does it have an internal capacitor that tries to eep it going or somthing

Sounds like a circuit error. Maybe the bus resistor values or what you are doing with the backup input pin.
Even without backup power, if you set the registers, they should read back as whatever you set them instantly, not after a period of time.
Double check that you are setting ALL of the time registers. Leaving one or more at an undefined value may well cause strange behaviour until it is 'clocked' internally.

I have not experienced what you are seeing with either the AXE110 or AXE033 when the battery is removed.

it's very odd behaviour... i think there is some kind of internal capacitor that keep part of the rtc going or somthing of that nature as far a curcuit error it can't be it's been working very well up untill i remove the power then after 5 mins it's ok again... but i'e solved the problem i have put in the watch battery and it's now perfect