Why Does Your Battery Keep Losing Its Charge?

You trust your battery to start your vehicle, but if your battery is not being sufficiently charged or is being drained of its power, your vehicle will simply shut down in the middle of the street. Although it’s normal to assume that a dead or weak battery is attributed solely to the condition of the battery, there are many reasons that your battery may be losing its charge.

The Battery

Of course, your battery is the primary suspect in its own demise, especially if it is a few years old or has been through extreme hot or cold temperatures. Extensive use of chargers and other auxiliary devices can also help to drain a compromised battery.

Any auto parts store will usually check your battery for free and recycle the old battery core if you need a new battery, but you need to disconnect it and carry it into the store. If your battery is tested and found to be in good shape, there are other reasons for the battery to fail to maintain an acceptable charge.

Check the terminals of the battery and the inside of the cable clamps that secure the cables to the terminals for signs of corrosion. It will appear as a white powdery substance, and you will need a piece of fine sandpaper to remove the corrosion. After reconnecting the cable clamps, you can also apply a corrosion inhibitor spray to the terminals and clamps to help to minimize future occurrences.

The Battery Cables

Battery cables tend to wear out first around the clamp connections, but a bare spot in the insulating cover can present itself anywhere along the length of the cables. When the wire inside a cable is exposed through a worn or torn spot, it can touch any steel surface of the vehicle and cause the battery to lose its charge.

A battery cable with various cracks or worn spots in the insulation covering should be replaced, but a single worn area in an otherwise sound cable can be covered by a few layers of electrical tape.

The Belt That Powers the Alternator

If your battery is sound and clean of corrosion and your cables look good, it’s time to move on to the charging system. Your battery is charged by the alternator, which is powered by your engine by a belt that spins between two pulley wheels. If the belt becomes worn or cracked over time, it will fail to turn the component within the alternator that produces the charge for your battery.

Depending upon your vehicle, the alternator is powered by a single dedicated belt between engine and alternator or by a serpentine belt that services multiple vehicle components. You can inspect either type of belt for signs of wear by visual, audible and physical checks.

The belt should be free of visual cracks or thin areas, and the inner surface should have a dull color. A shiny inner surface indicates wear from friction as the belt slips on the pulleys, losing its effectiveness in turning the alternator’s charging component. A loose belt may also produce a chirping or squealing sound when the vehicle is started or with rapid acceleration.

A belt should not be so tight that it will not move if lifted with one finger (when the vehicle is turned off, of course), but it shouldn’t move more than one half inch from its original position.

Belt replacement, particularly a serpentine belt, can be difficult for amateurs, because belts require tensioning, which tightens a belt in place around pulley wheels. Belt tensioners differ among vehicles and require physical prowess and perhaps special tools for some models.

The Alternator

If all other components of the charging system are operational, It’s likely that your alternator is failing. You can get it checked at your local auto service center and have it replaced before it fails completely. While alternator replacement can be expensive, a service center can often suggest a quality aftermarket substitute for the alternator brand that was originally installed in your vehicle.

If you’re in the San Rafael or Marin County areas, Neuhaus Service, Inc. is the place to go. We’ve been helping our customers to keep their vehicles in top shape for over 42 years and are always looking for a new lifetime customer.‚Äč


3241 Kerner Blvd, #10A
San Rafael, CA 94901