Ok, here's the deal. In January, I did a Hydrometer test of my car battery and noticed that one cell was weaker than the others.
In June, I had some car work performed at the dealer and I asked them to check the battery. Their fancy tester says everything is fine.
The car had been sitting for about 5 weeks and I had it out the night before. The next day, embark on a 40 mile trip to a major city in the US. I get to my destination, and idle the car with the AC on for 5 minutes or so and the battery light comes on just before the car dies and would not restart. I did check the alternator belt when the car was stopped. I just pushed on the belt,
I finish my business and get in the car and drive to another parking lot and I parked under a tiny tree. I idle there for a while and the car dies and would not restart. I do my business and call for towing.
The tow truck arrives fairly quickly and I get towed to a shop about 4 miles away. They said the alternator belt snapped and they could not perform the electrical testing until they replaced that, So, in about 45 minutes thay say everything is fine and I'm on my way home. I stopped to eat a few blocks away. Car started.
4 days later, I tried to start the car and the battery is dead. I had turned the dome light (changed to LED based some time ago) to the off position days earlier.
My troubleshooting the next day revealed all of the cells were dead (Hygrometer) except one which had a tiny indication of charge. Car jumped fine. I did my two quick and dirty tests:
1. Voltage across battery with engine running: 13.8 and doesn;t vary with RPM, so OK
2, From a previous measurement, of the voltage ACROSS the lead connecting the battery to the alternator, I get about 300 mV which indicates charging.
3. Another test I might perform is to take a scope and look at the ripple, but I didn't do that.
So, two shops telll me my battery is fine and a $4.00 piece of plastic told me it wasn't.
I asked the 2nd shop whether their tester measures ESR (Effective Series Resistance) and got "I'm not sure". I do have the ability to perform a "load test", but I didn't do that either.
So, what happend?
Do, the shops not know what a hydrometer is?
In June, I had some car work performed at the dealer and I asked them to check the battery. Their fancy tester says everything is fine.
The car had been sitting for about 5 weeks and I had it out the night before. The next day, embark on a 40 mile trip to a major city in the US. I get to my destination, and idle the car with the AC on for 5 minutes or so and the battery light comes on just before the car dies and would not restart. I did check the alternator belt when the car was stopped. I just pushed on the belt,
I finish my business and get in the car and drive to another parking lot and I parked under a tiny tree. I idle there for a while and the car dies and would not restart. I do my business and call for towing.
The tow truck arrives fairly quickly and I get towed to a shop about 4 miles away. They said the alternator belt snapped and they could not perform the electrical testing until they replaced that, So, in about 45 minutes thay say everything is fine and I'm on my way home. I stopped to eat a few blocks away. Car started.
4 days later, I tried to start the car and the battery is dead. I had turned the dome light (changed to LED based some time ago) to the off position days earlier.
My troubleshooting the next day revealed all of the cells were dead (Hygrometer) except one which had a tiny indication of charge. Car jumped fine. I did my two quick and dirty tests:
1. Voltage across battery with engine running: 13.8 and doesn;t vary with RPM, so OK
2, From a previous measurement, of the voltage ACROSS the lead connecting the battery to the alternator, I get about 300 mV which indicates charging.
3. Another test I might perform is to take a scope and look at the ripple, but I didn't do that.
So, two shops telll me my battery is fine and a $4.00 piece of plastic told me it wasn't.
I asked the 2nd shop whether their tester measures ESR (Effective Series Resistance) and got "I'm not sure". I do have the ability to perform a "load test", but I didn't do that either.
So, what happend?
Do, the shops not know what a hydrometer is?