Passat Wagon L4-1.9L DSL Turbo (AHU) (1997)
Battery: Component Tests and General Diagnostics
"In-Stock" Batteries
NOTE: Batteries that have not been used for a lengthy period of time eventually discharge themselves, and may become sulfated. If these batteries are
boost-charged using a conventional charger they may not accept the charging current, or may only take on a "surface charge" and then prematurely test
"fully charged".
Although a boost-charged battery appears to be malfunctioning, check it first, as follows:
-
Check specific gravity in every cell.
-
Readings must not deviate by more than 0.040 from each other (example: When the highest specific gravity reading is 1.150, none of the other cell
readings should fall below 1.110.)
If cell readings are within 0.040 of each other:
-
Perform complete battery charging procedure. See: Service and Repair (Charging Battery(ies).)
-
Perform load test to determine if battery is actually malfunctioning.
If reading in one or two adjacent cells is noticeably lower (example: five cells are 1.160, one cell 1.080):
-
Battery has short circuit and is malfunctioning
Load Testing
Requirements:
-
Battery at least 75 % charged.
-
Battery ground (GND) strap disconnected.
-
Battery load tester connected per manufacturer's instructions (Christie Automotive BT-900 or equivalent)
NOTE: The load current and the minimum voltage varies, depending upon the capacity of the battery and should be taken from the sticker on the
heavy discharge tester, or taken from the following chart:
Load Current And Minimum Voltage
Alternate method: 1/2 of Cold Cranking Amps for 15 seconds
NOTE:
-
If the minimum voltage is too low after a load period of 5-10 seconds, the battery is discharged or faulty; check specific gravity.
-
If the battery is colder than room temperature, voltage under load will be lower than the specified value.
CAUTION: Batteries with a capacity in excess of 63 Ah must not be tested with the battery test and charging unit VW 1266, as the tester is only
intended for batteries up to a maximum of 63 Ah.
If battery must be tested cold, use chart below as a guide.
Approximate
Minimum Acceptable
Electrolyte Temp.
Voltage Under Load:
F(C):
60 (16)
9.5 Volts
50 (10)
9.4 Volts
40
(4)
9.3 Volts
30 (-1)
9.1 Volts
20 (-7)
8.9 Volts
10 (-12)
8.7 Volts
0 (-18)
8.5 Volts
Sealed Battery Voltage Test