fuel air mixture in combustion chamber 106 simultaneously ecm 27 switches driver motor 101 to a separate electrical circuit converting driver motor 101 to a generator as the fuel air mixture ignites in chamber 106 a rapid rise in pressure occurs forcing the driver assembly 14 and piston 15 down cylinder 13 ejecting nail 40 into the substrate or work piece as the driver assembly 14 and piston 15 progress down the cylinder 13 motor 101 now acting as a generator is in communication with driver assembly 14 via rack 11 and gear 7 the resulting charge is sent back into the battery pack 105 increasing battery tool cycles between charges as the driver assembly driver 14 and piston 15 reach 90 of travel the underside of piston 15 comes into contact with bumper shock absorber 8 which reduces the kinetic energy of driver 14 and piston 15 bringing them to a steady controlled stop in cylinder 13 at this stage of the tool combustion cycle the exhaust ports 10 configured in plurality at the base of cylinder 13 are uncovered by piston 15 the exhaust gases in chambers 106 and 107 escape evacuate through exhaust ports 10 reducing the gas pressure in chambers 106 and 107 to a partial vacuum lower pressure than ambient the stored energy in bumper 8 then repels the driver assembly driver 14 and piston 15 approximately thirty percent 30 back up bore 13 ecm 27 then switches fan motor 102 back to normal running mode at 12v simultaneously ecm 27 in communication with driver motor 101 checks the position of the driver assembly driver 14 and piston 15 and adjusts.