S4 Quattro Cabriolet V8-4.2L (BHF) (2008)
Battery: Component Tests and General Diagnostics
Electrolyte Level, Checking
Battery
The battery is one of the most important electrical components in the vehicle. Its proper functioning is a major factor in ensuring customer satisfaction.
To guarantee a long service life, the battery must be checked, serviced and maintained as described in this service information.
In addition to its function of starting the vehicle, the battery performs other tasks as a buffer and a source of electrical energy for the vehicle's entire
electrical system.
Electrolyte Level, Checking
CAUTION!
‹› Observe accident prevention directions when handling electrolyte.
‹› Appropriate safety clothing is required.
‹› Illuminate the inner part of the battery housing using only a flashlight.
‹› Never illuminate the interior of the battery housing using an open flame.
‹› Keep open flames and burning cigarettes away from batteries.
‹› When disposing of batteries, always observe the appropriate regulations for batteries and sulfuric acid.
‹› To ensure proper sealing of the different battery plug systems, it is necessary that the original battery plugs are tightened into the
battery openings. In case of loss or damage, only original sealing plugs of the same type may be used.
‹› The plugs must be installed with an O-ring seal.
Special tools, testers and auxiliary items required
‹› battery fill bottle (VAS5045)
‹› Hydrometer, commercial type
‹› Maintaining the correct electrolyte level in the battery is an important factor affecting the length of the battery's service life.
‹› Batteries which have visible minimum and maximum marks require only visual inspection of the outside of the battery to check the electrolyte
level.
‹› The electrolyte level must be above the minimum mark, but may extend only as far as the maximum mark.
‹› If external min.. and max. marks on a battery are not readily visible, or if electrolyte level cannot be checked properly due to an opaque battery
casing, battery caps must be unscrewed. It is then possible to check electrolyte level by performing a visual internal check of battery.
‹› The electrolyte level must stop at the inside electrolyte level mark (plastic web). This corresponds to the exterior max. mark.
‹› For batteries with a charge indicator - arrow -, the electrolyte level can be read from the color indication.