Portable drawn arc stud welder including a lithium ferrophosphate battery

A portable drawn arc stud welder apparatus for welding a stud onto a workpiece, the portable drawn arc stud welder apparatus including:

• a housing;
• a lithium ferrophosphate (LFP) battery disposed in the housing and including a plurality of LFP battery cells;
• a weld stud gun configured to hold a stud electrically connected to the LFP battery for receiving energy from the LFP battery to pass a current through the stud and the workpiece to form a weldment;
• a stud weld battery control system (SWBCS) disposed in the housing electrically connected to the LFP battery of the portable drawn arc stud welder apparatus, wherein the SWBCS includes a processor, and a memory, and instructions therein, to implement control and monitoring of the operation of the portable drawn arc stud welder apparatus;
• the SWBCS configured to measure a rate of change of a voltage of the LFP battery after a sequence of consecutive welds and to determine whether the measured the rate of change exceeds a predetermined rate of change level;
• the SWBCS configured to balance the plurality of battery cells and then measure a temperature of the LFP battery via temperature sensors against a predetermined temperature range at least after the SWBCS balances the plurality of battery cells;
• the SWBCS configured to activate one or more fans disposed in the housing in response to the measured temperature of the LFP battery exceeding a predetermined temperature level and/or if a calculated welding rate exceeds a predetermined welding rate and the SWBCS configured to selectively operate the one or more fans in response to the measured temperature dropping below the predetermined temperature level and/or if the calculated welding rate exceeds the predetermined rate;
• a weld stud gun coil capacitor electrically connected to the SWBCS;
• and
• the SWBCS configured to measure a charge level of the weld stud gun coil capacitor after the SWBCS measures the temperature of the LFP battery via the temperature sensors against the predetermined temperature range.