Knowing how to jumpstart a car battery is a good skill to have—but what happens when it’s not enough? Most of the time when your car won’t start, you assume it’s because there is a problem with the battery. You pull out the jumper cables, jump start it and go on your way. But what if the very same problem occurs the next time you get in the car?
This simply means that your car battery isn’t holding a charge. But why? There are several different causes that could be behind your run-down battery.
The Causes of a Failed Charge
Here’s a quick rundown of some of the most common causes of a battery that won’t hold a charge:
- You’ve left your lights on, or some other accessory that draws battery power even when your car isn’t running.
- When you drive the car, the battery isn’t getting recharged, i.e., there is a mechanical charging problem.
- There is a parasitic electrical drain on the battery, possibly caused by a bad alternator.
- The battery is simply old and it’s time for you to replace it.
Diagnosing the Problem
While there are multiple causes of a failed charge, you might be wondering how to determine exactly which one is to blame. Perform the following tests to find out:
- The first thing to do is try to turn on your headlights. If they come on with their normal brightness, your problem is probably a bad starter or poor wiring—not the battery. If the lights do not come on at all, or if they’re dimmer than normal, then the problem is more likely with the battery.
- To test the voltage of your battery, get a voltmeter and connect the red lead to the positive terminal, the black lead to the negative terminal. Hopefully, you’ll get a reading of over 12.6 volts, showing a fully charged battery—but if not, there’s definitely an issue with the battery being poorly charged.
- At some point, you’ll want to ask yourself about the condition of the battery itself. Does it look obviously corroded or worn out? Is it more than four years old? If so, then the simplest solution may be to have the battery replaced.
- Something else to consider is that the problem is your alternator. If you detect cracking or fraying in the alternator cables, that’s an obvious sign that something’s off. And if you jump start the car only for the battery to quickly lose its charge and the engine to stall, that’s suggestive of an alternator issue.
Even if you do believe you’ve discovered the exact problem, you’ll probably want to get an expert opinion. Buying a new battery when the alternator is the real problem—or vice versa—will prove highly frustrating when you end up spending more money than necessary. Bring your car to a local car care center for an inspection so you can get to the bottom of what’s truly causing your lost charge.