Have you ever said ‘Good Night ‘ to your car and you were unable to start it the next day? Loss of battery charge can occur for a number of reasons. Many reason could be responsible  for the drain you experience in your car battery but the four major causes will be discussed in this article

If you have  your radio presets, security alarms or clocks running after the engine is off, it can drain your battery. This type of drain is known as parasitic drain. Parasitic drains below 75 milliamps are normal, but any parasitic drain over 75 milliamps will drain the battery quickly. The most common causes of parasitic drain are under hood lights, trunk lights, headlights or glove box lights that do not turn off when the door is closed. Relay switches that are stuck in the “on” position can also cause a battery to drain.
A faulty or unreliable charging system can also drain the battery while the car is running. When an alternator is not pushing out enough voltage, which should be between 13.5 and 14.5 volts, the battery will drain quickly. This is especially true if you play the radio and lights while driving. Once the car battery drains completely, the headlights and radio will not operate. The car will stall and not start again until the battery is charged.
Alternators with bad diodes can cause battery drain. An alternator with a good diode allows current to flow in one direction. A bad diode can leak and allow the current to flow in the opposite direction. When this happens, it may keep the charging circuit on after the vehicle engine is shut off, which will cause the battery to drain.
Batteries that are old or have been drained continuously may not hold a full charge anymore. The rule of thumb for replacing a battery is every four to five years. However, some batteries can last years longer if taken care of and not run down while the charging system is not running. Batteries that are allowed to freeze over an extremely cold winter may also have problems holding a charge.


1.Make sure all of the interior lights are off and that nothing is left on that could drain the battery. You should also never leave the radio on for an extended period of time when you do not have the car running.

2.Keep the battery clean. Use a dry rag to wipe off any dirt or residue near the terminals and connection areas. An unclean battery can sometime be the cause of its drainage.

3.Check to make sure that the cable connections to the battery are tightened and clean. A loose or dirty connection can cause drainage and other problems to the battery.

4.Use a portable car battery charger or volt meter to test and charge the car’s battery if it is below performance level. You can purchase a charger at a local automotive retailer and then use the charger’s jumper cable to test the wattage of the battery.

5.Take your car into an automotive specialist if you continue to have problems with the battery or if you have recurring trouble with the engine turning over. If you replaced the drained battery with a new one yourself then you should make sure you know the cause of the drainage so the problem does not continue.


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  1. Debi Reply

    I do not know what else to say.
    Your posts have been much more than informative and helpful.

    This comment is multiplied by all posts here.

  2. ify Reply

    Thanks for putting this information out. Its priceless, well done everyone! Cheers

  3. Ebenezer Reply

    Hi, kindly enlighten me about kick starter faults, repairs and replacement options. My car wouldn’t just start until I beg for a push. And I have changed my battery.

  4. Allan Jay Reply

    Big help! Thanks!

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