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Hello All:
1967 Volvo 122S Wagon. As some of you may recall, I have a battery that intermittently holds its charge for reasons unknown. Some have suggested getting an alternator, but I noticed some interesting things that I wanted to share:
- I checked the voltage across the battery - 11.75 volts. BAD.
- I charged the battery, and when I reinstalled it the ground strap that goes from the negative terminal to the chassis broke at the terminal clamp. "Ah-Ha!" I thought, thinking I had solved my problem.
- $7.50 later, I had a brand new sweet braided ground strap installed. Battery voltage measured around 12.5. The engine started, no problem. 'Success', I thought.
- I measured the battery voltage when revving the engine to 1,500 RPM. No noticeable change in voltage. I know it should be going to about 14.5 volts so I know I need to replace the brushes at least - the question is, was this a pre-existing condition?
- Then, something weird happened. Wendy drove the car. Parked somewhere, started it up no problem and drove it home. Typical behavior, as we would expect. Approximately four or five hours had passed since the charge and when she started it for the last time. The next day when I went to start the car it would not turn over. Dang!
- I checked the battery voltage - it was in the mid-hundreds of MILLIvolts and slowly dropping. This was with nothing on in the car, even the dome light, although I had turned on the headlights a few times to test the repaired hi-low dipper switch. Ignition key in the 'off' position, lights off.
- I decided to pull the battery and recharge it but for some reason, after pulling the terminals off I decided to recheck the battery voltage. 4.5 volts and rising at a pretty good clip!
- I reattached the negative terminal clamp. Still rising towards 5 volts...
- I reattached the positive terminal clamp. Immediately went to mid-hundreds of millivolts and slowly dropping.
- I detached both clamps - back to 4.6 volts, and rising. I left the battery in that state and drank too much wine.
- Later that evening, I went back outside and measured the battery voltage - 11.75 volts.
- I pulled it and charged it this morning. When I pulled it off the charger it was 12.62 volts but started dropping, about 1/100 volt every four or five seconds.
I left the battery on my workbench and will check the voltage tonight when I get home to see where it settles.
Why would attaching the positive terminal immediately sap so much voltage from the battery?
Cheers,
Jeff Pucillo
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