Acid Density
WARNING: This page is about a different car, the 2010 Volvo V70, 2009 Volvo V70, and 2008 Volvo V70. However, it is still accessible from the selected car via links, so may be relevant.
The unit showing the amount of sulfuric acid in the electrolyte and is a measurement of the battery voltage and charge status. The density of the acid is measured in g/cm3 . The higher the value of the acid density (i. e. high concentration of sulfuric acid), the higher the voltage and state of charge. A low acid density value means a correspondingly low concentration of sulfuric acid, low voltage and a reduced capability for providing current. The electrolyte in a fully charged battery has a density of 1.28 g/cm3 . The density of the electrolyte in a fully discharged battery is 1.10 g/cm3 .
HINT: For maintenance-free as well as sealed batteries (AGM) the battery acid cannot be accessed and thus its density cannot be measured.