Ok guys and gals. Here is the first lesson in shop class that many missed in high school. How to test a Battery 101. This will provide all the step by step info you need to determine what is going on, how to isolate if it is a battery, cables, system drain, and if your going to need to stop playing and throw away the battery.
Tools, testers, chargers, and common sense are all explained in detail.
Next up: Charging Systems
Nope this is not mine. All that was required was a simple search on Google to find someone who understands test procedures.
Cliff Notes: DC Digital Volt Meter Testing
Temperature Compensation Table
Open Circuit Voltage Approximate State-of-Charge at 80°F (26.7°C) Hydrometer Average Cell Specific Gravity Electrolyte Freeze Point
12.65 100% 1.265 -77°F(-67°C)
12.45 75% 1.225 -35°F(-37°C)
12.24 50% 1.19 -10°F(-23°C)
12.06 25% 1.155 15°F(-9°C)
11.89 or less DISCHARGED 1.120 or less 20°F(-7°C)
DURING*the load test, the voltage on a good battery will NOT drop below the following table's indicated voltage for the electrolyte at the temperatures shown:
LOAD TEST
Electrolyte Temperature °F Electrolyte Temperature °C Minimum Voltage Under LOAD
100°F 37.8°C 9.9Volts
90° 32.2° 9.8
80° 26.7° 9.7
70° 21.1° 9.6
60° 15.6° 9.5
50° 10.0° 9.4
40° 4.4° 9.3
30° -1.1° 9.1
20° -6.7° 8.9
10° -12.2° 8.7
0° -17.8° 8.5
Secondary source
Battery Testing, Maintenance And Myths
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2005 X5 4.8IS
The
Blue ones are always FASTER....
Current Garage:
2005 X5 4.8is
2002 M5 TiSilver
2003 525iT
1998 528i
Former Garage Stable Highlights
2004 325XiT Sport
1973 De Tomaso Pantera, L Model
1970 Dodge Challenger T/A 4 sp Alpine White
1970 Dodge Challenger T/A 4 sp GoManGo Green
1971 Dart Sport, “Dart Light” package
1969 Road Runner 383
1968 Ply Barracuda 340S FB Sea-foam Green