BARTINGTON INSTRUMENTSPage 10 of 18 OM2443/4When all 5 cells are in place, locate the back edge of the lid in the enclosure.A BTighten screws A and B in any order.6.2. Initial Charging of the Battery CellsTo charge the PSU1 batteries, connect the mains charger and switch on the mains supply (ifappropriate). The charging LED [3] will begin to flash indicating that “fast charging” is takingplace. Once the fast charge cycle has completed, the LED will stop flashing and be lit (ON)continuously, to indicate that “trickle charging” is continuing.Note: When battery cells are inserted for the first time, they should be continuouslycharged for 16 hours to ensure full capacity.Note: The PSU1 can be used whilst charging the battery cells or used directly from mainspower without any battery cells being installed. However, the outputs may carry somecharger noise.Note: If the PSU1 is powered by the mains charger with no battery cells installed, thecharging LED may flash. This is normal and can be ignored.Note: The charging LED will switch off when the batteries are fully charged.Note: To prepare for long periods away from a charging source, battery cells may be pre-charged and used to replace discharged cells in the field.