Odds are good that the only time you think about your car battery is when you turn the ignition key and are greeted with either nothing but clicks or the sound of the engine making a few halfhearted attempts to turn over. Most drivers have been in this frustrating predicament at one time or another, and it usually happens when they are running late for an important appointment or have some other pressing reason to be on their way. The next time this happens to you, it will most likely be due to one of three things.
You Need a New Battery
Modern automobile batteries are solidly made and built to provide years of faithful service, but they do not last forever. Regularly allowing car batteries to run down will shorten their lives as will extremely cold temperatures and taking lots of very short trips. When a car battery keeps draining, it is often a sign that trips are being taken that are not long enough to allow the alternator to recharge the battery fully. If you think that your battery is reaching the end of its road, you may be wise to eliminate other electrical problems before investing in a new one. Such problems include:
- Loose or worn battery cables
- Some sort of short circuit
- A faulty alternator
- A defective starter
- Fouled spark plugs
You Left Your Lights On
We have all left our headlights or interior lights on by accident and spent much of the following morning cursing our mistake. Auto manufacturers understand how enraging this can be, and most modern vehicles are fitted with buzzers or chimes to warn drivers when they remove the ignition key before switching everything off. However, consumers are fickle and tend to eschew jarring or excessively loud warnings in favor of more subtle alerts, which defeats the whole purpose of having such a system in the first place.
Some cars have headlights that are designed to stay on for several seconds to illuminate dark driveways, but this added convenience often leads to further frustration as drivers stand waiting in the freezing cold or pouring rain just to make sure that their lights actually switch off.
You Have Fallen Victim to Vampires (not that kind) or Parasites
When a car that was running fine the night before does not start, parasites or vampires are often to blame. Parasitic or vampire draw are terms used to describe the energy that is sapped from car batteries while their owners are sleeping peacefully in their beds. This current makes sure that radio stations are remembered, clocks tell the right time and alarms are doing their jobs, and it is not usually enough to make much of an impact on battery performance.
However, vampire draw can become a problem when batteries are old, neglected or cars sit idle for days or weeks at a time. If this is a recurring problem, it could be caused by faults in one of the systems that draw power when cars are not in use. Alarms are a common source of these frustrations. If you are wondering what can drain a car battery when its off, the vampires or parasites responsible could include:
- The stereo or infotainment unit
- The satellite navigation system
- The alarm or security system
- The engine computer’s internal memory
- Body control modules
Car Battery Q and A
What drains a car battery?
Car battery drain is usually caused by a major system, such as the headlights, being left on, but it can also be caused by prolonged periods of idleness, extreme temperatures, frequent brief journeys or a defect of some kind.
Can I place a car battery on a concrete floor?
What is known as garage floor drain was once a major cause of car battery drain, but the plastic shells that modern car batteries are encased in protect against concrete. This means that garage floor drain is rarely a problem today.
Are maintenance free batteries really maintenance free?
While they may not require regular fluid top ups, maintenance free batteries should be checked every now and then for corrosion, loose cables and other signs of damage or disrepair.
Is a more powerful battery always better?
Modern automobile electrical systems are extremely sophisticated, and they only draw the power they need no matter how mighty the battery connected to them is.