Battery pack and charger platform for power tool systems including battery pack identification scheme

Abstract

A battery pack and charger platform including a voltage coupling circuit comprising an input that receives an input voltage and an output that sends an output voltage, a voltage monitoring circuit having an input coupled to the voltage coupling circuit output and an output, and a power source having an input coupled to the voltage monitoring circuit output, the power source input receives an input voltage representative of a charge instruction.

1 - 19 . (canceled) 
     
     
         20 . A battery pack system, comprising:
 a set of battery packs, the battery packs set including L elements, each battery pack of the battery packs set including a different number M of battery cells, where 2≦M≦N and where L≦2 and N>L,   each battery pack of the battery packs set including a set of battery terminals, the battery terminals set including O elements, where O<N,   a first subset of the battery terminals set, the first battery terminals subset including P elements, where 0≦P<O, each battery terminal of the first battery terminals subset coupled to a battery reference node, and   a second subset of the battery terminals set, the second battery terminals subset including Q elements, where Q=O−P, each battery terminal of the second battery terminals subset coupled to a battery measurement node.   
     
     
         21 . The battery pack system of  claim 20 , wherein the battery reference node is a battery positive voltage node. 
     
     
         22 . The battery pack system of  claim 20 , wherein the battery measurement node is a node between battery cells. 
     
     
         23 . The battery pack system of  claim 20 , wherein L=3 and N=5 and O=4. 
     
     
         24 . A battery pack comprising:
 a set of battery terminals, the battery terminals set including O elements,   a first subset of the battery terminals set, the first battery terminals subset including P elements, where 0≦P<O, each battery terminal of the first battery terminals subset coupled to a battery reference node, and   a second subset of the battery terminals set, the second battery terminals subset including Q elements, where Q=O−P, each battery terminal of the second battery terminals subset coupled to a battery measurement node.   
     
     
         25 . The battery pack of  claim 24 , further comprising a set of battery cells, the battery cells set including M elements and where 2≦M≦N and where N>O. 
     
     
         26 . The battery pack of  claim 24 , wherein the battery reference node is a battery positive voltage node. 
     
     
         27 . The battery pack of  claim 24 , wherein the battery measurement node is a node between battery cells. 
     
     
         28 . The battery pack of  claim 25 , wherein N=5 and O=4. 
     
     
         29 . A battery pack and battery charger platform, comprising:
 a set of battery packs, the battery packs set including L elements, each battery pack of the battery packs set including a different number M of battery cells, where 2≦M≦N and where L≧2 and N>L,   each battery pack of the battery packs set including a set of battery terminals, the battery terminals set including O elements, where O<N,   a first subset of the battery terminals set, the first battery terminals subset including P elements, where 0≦P<O, each battery terminal of the first battery terminals subset coupled to a battery reference node, and   a second subset of the battery terminals set, the second battery terminals subset including Q elements, where Q=O−P, each battery terminal of the second battery terminals subset coupled to a battery measurement node,   a battery charger including a set of charger terminals, the charger terminals set including O elements, the battery charger configured to mechanically couple to each battery pack in the battery packs set such that each charger terminal mechanically and electrically couples to a corresponding battery terminal.   
     
     
         30 . The battery pack and charger platform of  claim 29 , wherein the battery charger is configured to determine the number of battery cells in the battery pack coupled to the battery charger based on P.