Patent ID: 7592773

Claim:
A portable self-contained electrical power tool assembly, comprising: a first subassembly forming an electrical actuator and generating the mechanical action of the tool; a second subassembly forming an electric energy source and comprising essentially a rechargeable electrochemical battery; and a third subassembly forming a charger adapted to carry out controlled recharging of the battery, wherein: the second subassembly ( 3 ) is portable by an operator and is constituted by a lithium ion or lithium polymer electrochemical battery ( 5 ) formed by association of more than four cells ( 6 ) in series, each cell being comprised by one or several elements in parallel and, the second subassembly ( 3 ) is also constituted by an electronic command and control module ( 7 ) for the battery ( 5 ), in the form of an electronic device located in immediate adjacency to said battery ( 5 ) and ensuring over time and in a controlled manner a maximum capacity of the battery and an optimum use of the tool; the first subassembly ( 2 ) is subjected during its operation to control by a system ( 8 ) of current limitation adapted to reserve the lithium ion or lithium polymer electrochemical battery ( 5 ) from which it draws energy; the third subassembly ( 4 ) comprises at least a source of electrical supply whose voltage and current are suitable to recharging the lithium ion or lithium polymer battery ( 5 ), the electronic command and control module ( 7 ) of the battery ( 5 ) fulfilling at least tasks i) to v) as follows: i) management of charge, ii) management of discharge, iii) balancing the charge of each cell ( 6 ), iv) protection in discharge of the battery ( 5 ) as to excess current during utilization of the tool, v) management during storage, and vi) management of diagnostics, wherein when the tool assembly is not charging and has not been used for a predetermined period the digital processing unit ( 9 ) automatically performs a task of management of storage which comprises verifying whether the residual capacity of the battery ( 5 ) is greater or not than the storage capacity predetermined by the manufacturer or lithium ion or lithium polymer elements and, if the residual capacity is substantially superior to the storage capacity, in triggering by the digital processing unit ( 9 ) an automatic discharge of the battery.