LEMON Manuals: Even more car manuals for everyone
Home >> Audi >> 2010 >> S4 Automatic DCT >> Repair and Diagnosis >> External Pages >> Different car >> Section 159 (Starting System & Charging System (H4DO)) >> Battery >> Inspection >> Specific Gravity Of Electrolyte

Specific Gravity Of Electrolyte

WARNING: This page is about a different car, the 2012 Subaru Forester. However, it is still accessible from the selected car via links, so may be relevant.
  1. Measure specific gravity of electrolyte using a hydrometer and a thermometer.

    Specific gravity varies with temperature of electrolyte so that it must be corrected at 20°C (68°F) using the following calculation:

    20  = St + 0.0007 x (t - 20) 

    20  : Specific gravity corrected at electrolyte temperature of 20°C 

    St: Measured specific gravity 

    t: Measured temperature (°C) 

    Judge whether or not the battery requires charging according to corrected specific gravity. Standard specific gravity: 1.220 - 1.290 [at 20°C (68°F)] 

  2. Measuring the specific gravity of the electrolyte in the battery will disclose the state of charge of the battery. The relation between specific gravity and state of charge is as shown in the figure.
    Fig 1: Electrolyte Specific Gravity Characteristics Graph
    G07665203Courtesy of SUBARU OF AMERICA, INC.