Patent ID: 11931219
Assignee: 3M INNOVATIVE PROPERTIES COMPANY
Field: Medical technology (Instruments)
Classification: CPC A  H | IPC A  H

Claim 0:
1. A method of charging a battery of a dental light irradiation device, comprising the steps of:
(a) powering the battery at a first charging current I1 and simultaneously at least temporarily measuring a first terminal voltage U1 of the battery;
(b) powering the battery at a different second charging current I2 and simultaneously at least temporarily measuring a second terminal voltage U2 of the battery;
(c) calculating a battery source voltage UBAT based on the formula:, U
    
      B
      ⁢
      A
      ⁢
      T
    
  
  =
  
    
      
        
          U
          1
        
        ·
        
          I
          2
        
      
      -
      
        
          U
          2
        
        ·
        
          I
          1
        
      
    
    
      
        I
        2
      
      -
      
        I
        1
      
    
  

 and
(d) repeating steps (a) to (c) while the battery source voltage UBAT is below a predetermined threshold voltage, and powering off the battery as soon as the battery source voltage UBAT reaches or exceeds the threshold voltage.