Each main turbo pump (MTP) has an adjoining box containing (4) ea. 12v 18Ah sealed lead acid (SLA) batteries connected in series that provide 48VDC for pump rotor levitation during loss of AC power.  These only get charged when the turbo controllers are energized.  As preventative maintenance during the prolonged periods of pump inactivity, we would energize the controllers for a few hours during Tuesday's maintenance period.  We now will keep these battery packs centrally located (hallway between AHU1 and AHU2 in the Corner Station Fan room) and on a battery tender.  The trade off is that we now will need to remember to take a battery pack with us when activating an MTP at an outbuilding.