I dont think disconnecting your battery is the issue.... I have had mine on and off multiple times in the last few weeks and not driven the car anywhere.... I drove it the 40 miles to Woodburn this morning and my first run was 11.96sec, second was 12.1sec (operator error) and third was 12.0sec... these runs were one hour between each and the DA was -726' on #1 and -667' on #3.... my worst run of 12.1 was at DA of -743'....but that was my launch.....

It certainly wont hurt to get some time on the ECU..... but I dont think it is going to make a difference...