Performed preventative maintenance for a Lennox AC system. Model #14ACXS036-230A20, serial #1916H43924. Upon arrival the thermostat was turned off. I powered down the system and removed the access panels. The evaporator coils are clean and in good condition. Tested the drain pan, drain line and condensate pump with several bottles of water to ensure that there are no leaks or clogs. I replaced the 16x25x1 pleated air filter supplied by the homeowner. Checked all electrical connections to ensure that they are secure and in good condition. I re attached the access panels and powered the system back up. I replaced the batteries in the thermostat with batteries supplied by the homeowner. I called for AC and observed the system starting normally. The condenser coil’s are clean and in good condition. The condenser amp draws are .86 for the fan and 7.49 for the compressor. The temperature split is at a 20° differential. The system is operating properly at this time. Updated the power storage