@richardhenry, that procedure calibrates the battery chip, not the PMU. The PMU (Power Management Unit) was a chip on the logic boards of New World PowerPC Macs that managed power-related functions like sleeping, waking, charging, etc. On Intel macs, that chip has been replaced by the SMC (System Management Controller), which can be reset using this procedure.
In addition, the Apple-specified battery calibration procedure specifies that the computer should be fully charged, left for two hours, then fully discharged, left for five hours, then fully charged again.
The battery calibration isn’t a terrible thing to do, but I usually associate battery uC problems with symptoms like suddenly dropping charge, unexpected poweroffs, etc. Let us know how that goes if you do it.
TitsMcGhee, if you do an SMC reset and it doesn’t help, the information that the command-line tool “pmset” provides can be useful. In the Terminal, type “pmset -g rawlog” to get a display of everything the battery is reporting to the computer. Paste it here and maybe we can pull something out of it.