I have a 01 Ford Focus with 130k on it. When leaving for work two mornings ago the car would not start. There was a slow crank followed by clicking. I had been listening to the radio with the car off for a short time and assumed that had put too much strain on the battery. The car started right up when jumped.

The next morning the same thing occurred. This time I hadn’t used the radio. I also had checked to be sure nothing had been inadvertently left anything on. Again, it started right up with a jump.

The battery is about a year old and was tested at the place I bought it (Walmart) and it was fine. Could it be the alternator? The charging light isn’t on, and once the car is jumped it runs fine even with all of the accessories on (lights, a/c etc.). I’ve never had to replace an alternator before, and I always thought the car would eventually die after using up all of the battery power, but that doesn’t seem to be the case.

What are you opinions?

Well either the battery isn’t getting the proper charging from the alternator for some reason or there is an excessive current draw on the battery while the car is parked. This is assuming that the battery is in good, top shape.

First off, you should charge the battery with a battery charger since it has a low charge on it. Check the alternator belt and make sure it is snug and make sure the alternator connections along with the battery connections are clean and snug tight. I recommend you clean the battery connections with a battery post cleaning brush. Using a voltmeter, check the voltage getting to the battery while the engine is running at around 2,500 RPM. You should have a voltage between 13.5 and 14.8 volts if the alternator is working like it should be.

If you still have a problem then there is a drain on the battery most likely. Here is a link that can help you deal with that.

Well a bad alternator won’t keep the car from starting, but it will keep the battery from being charged while the engine is running. Let’s go over the basics: It’s possible the battery has a problem, but it’s also possible that you have a loose connection at the battery terminals. Is there any corrosion on the terminals? Can you move them with your hand if you try?

I’d charge the battery properly, clean the connections and re-tighten them and go from there. A battery that has been jump started is not fully charged-only partially.