Checking battery

Information 

Before checking the battery with a battery tester, the voltage at the battery must remain static for a short time.

The described sequence must be followed to ensure this rest period is observed.

Checking functional state: 

1. Park the vehicle on the lifting platform.
2. Switch off lights, switch off ignition, remove ignition key and open the luggage compartment lid.

   Information 

   No loads (e.g. opening doors, switching on light/radio, etc.) may be activated while the vehicle is jacked up and raised on the lifting platform.

   The time is long enough for the battery to rest for a few minutes.

3. Remove battery cover. → Removing battery cover .

   Information 

   Before the battery test: 

   If the temperature of the battery cannot be estimated, e.g. if the outside temperature and the temperature in the workshop area differ considerably, the temperature of the battery must be measured using a commercially available infrared temperature gun, for example.

4. Connect battery tester to the vehicle battery.

   → "Workshop Equipment and Special Tools Manual" Chapter 3 Workshop Equipment Manual, 3.9.1 Battery testers/chargers

   Fig 1: Connecting Battery Tester To Vehicle Battery

   Courtesy of PORSCHE CARS NORTH AMERICA, INC.
5. The values (A), the actual battery temperature, the battery type, etc. must be input on the battery tester. Follow the operating instructions provided for the tester.
6. After a short time, the result of the test will be displayed. The functional state and the charge state, for example, will be displayed, depending on the type of tester.
7. Continue the procedure using the values displayed on the battery tester. Example in → 270601 CHECKING BATTERY WITH BATTERY TESTER

   Checking fluid level: 

   WARNING: Caustic fluids

   • Danger of chemical burns

   → Avoid contact with caustic fluid.

   → Wear personal protective gear.

   → Ensure that there is good ventilation.

   → If you do come into contact, wash off immediately with plenty of warm water and contact a doctor if necessary.

   Information 

   Observe accident prevention regulations when working with electrolyte (battery acid). Only illuminate the inside of the battery with a torch. Always keep naked flames or cigarettes away from batteries. Observe the disposal regulations for batteries and sulphuric acid.

8. Unscrew battery plugs.
   Fig 2: Unscrewing Battery Plugs

   Courtesy of PORSCHE CARS NORTH AMERICA, INC.

   Information 

   • Use a commercially available battery filling bottle. 
   • The correct acid level of the battery is an important factor for long and efficient operation of the battery. 
   • When the acid level is too low, a capacity loss (performance loss) of the battery occurs, which is caused by the cell plates drying out. If the cell plates are not surrounded by electrolyte (battery acid), it will lead to corrosion of the lead plates, plate bridges and cell connectors. The result of the corrosion is that battery functioning cannot be guaranteed. The battery will become useless. 
   • If the acid level is too high, damage can occur when the battery acid (sulphuric acid/water mixture) leaks out of the battery. 
9. Check the fluid level of the battery. If necessary, correct the fluid level by topping up to the marking with distilled water.
10. Position battery plugs and screw on securely → Tightening torque: 1.2 Nm (1.0 ftlb.)  .
11. Install battery cover. → Installing battery cover .