About 2 weeks ago i lost all the parameters for my colchester T110 lathe with 21i control,

After speaking to colchester i replaced the CNC battery behind the screen and re entered all of the parameters manually, encountering a few problems along the way!

When i switched the machine on this morning all of the parameters have gone again, i have checked the voltage across the battery and it is reading a steady 3v as it should,

What else will cause me to lose parameters? and what can i do about it?

Dave