How to Keep Your Car Battery Charging On

By the Mercury Team

Experts say a typical car battery, if maintained properly, should last about five to six years. A battery’s lifespan and performance can be impacted by a number of factors including weather extremes, humidity, leaving lights or the radio on when the vehicle is turned off, a loose battery connection, corrosion on your battery, or other drains on your car’s electrical system. Here are seven steps you can take to keep your car battery functioning properly so you keep getting a charge out of it.

1. Drive your vehicle: Your car’s alternator is a key part of the electrical system, designed to re-charge the battery each time it is driven. Leaving your car standing for days or weeks at a time is hard on your battery. If you are leaving town for an extended period of time, it’s a good idea to have a trusted friend or neighbor start your car for 5-10 minutes once or twice a week to help keep the battery from draining.
2. Don’t use car features or accessories while the engine is off: What can drain a car battery when it’s off? Headlights, dome lights, security and navigation systems, the radio and air conditioning are all powered by the electrical system, which gets re-charged while the engine is running. However, if the radio or lights remain on while the engine is off, this will drain your battery. Reading or dome lights left on in a car parked overnight are among the most common reasons for a battery to die. The 12-volt charger, or cigarette lighter, might be used to charge a cell phone or GPS and leaving these items plugged in will drain your battery, especially if the car is left sitting for an extended period.
3. Beware of hidden drains: If a battery dies repeatedly and you’ve checked for dome lights or other potential causes in the cabin, there may be a malfunctioning light in your glove box or trunk that isn’t shutting off automatically as it should. Other accessories could be to blame, or there may be a problem with the alternator. A mechanic can help identify such a drain in your car’s electrical system.
4. Have your battery inspected regularly: Numerous problems can arise with a battery over time, including dirt or grime, loose connections or the battery itself could come loose due to frequent shaking and vibration. Ask your mechanic to inspect your battery when you take your car in for an oil change or other maintenance. They can use a voltmeter to measure your battery’s performance and help identify other issues that may be affecting your vehicle’s electrical system.
5. Keep the battery terminals clean: Battery corrosion caused by acid, dirt or grime can cause your battery to not function properly. The good news is, there is a relatively easy do-it-yourself fix using items you may already have in your home: gloves, baking soda, an old toothbrush and petroleum jelly. Make sure the engine is off, then undo the cables to your battery (remove the negative or black cable first). Inspect the battery – if you see that it’s leaking or appears to be swollen, take the car to a mechanic ASAP. If it looks good, proceed by mixing one tablespoon of baking soda with one cup of water, dip the old toothbrush in and start scrubbing the terminals, periodically cleaning the toothbrush as you go. Use a spray bottle or damp rag to clean the terminals and allow them to dry. Next, dab some petroleum jelly on the terminals to help prevent further corrosion then re-attach the cables. Be sure to re-inspect your battery terminals every six months or so.
6. Park in the garage: During weather extremes, parking the car in your garage will provide a more temperate environment for your engine and put less stress on your battery. Avoiding weather extremes becomes more important as your battery gets older.
7. Battery water: Most car batteries use a liquid electrolyte solution to hold a charge, and this solution can be affected by hot or cold weather. Cold weather reduces the solution's ability to transfer full power (which is why it can be hard to start a car in winter). A battery heater can help keep the battery warm and functioning. Conversely, hot weather can cause the solution to evaporate, limiting the battery’s ability to hold a charge. If this occurs, a sulfur smell (think rotten eggs) may be present. Distilled water should be used to refill the solution, as regular tap water contains minerals and impurities that can damage battery cells. Know this: if you have to put water in your battery, it's a sign that you’ll need to replace the battery soon.

Follow these simple steps and your battery will keep you and your vehicle on the go for many years and miles!