How Do You Stop a Car Battery from Draining?

by Phil Borges // in Car

When a car battery is working well, you will not even sense its presence. But the moment it starts giving you trouble, it can be the most frustrating thing. Nobody wants to get ready for a long day’s work only to find that your car is refusing to budge.

It is important to keep your car active so the alternator can keep the battery charged. If a car sits idle too long, the battery will drain. Ensure all devices plugged into the car are also off if the car is inactive. It may even be useful to remove the battery if the car is not in use.

Several things that run on your car’s battery, including the radio, the hazard lights, the cigarette port, etc. How do you stop your car’s battery from draining when all these devices are also pulling power from it? The following sections will shed some light on the problem: 

How Do You Stop a Car Battery from Draining When Not in Use?

The main function of a car is that it must be driven. If you let your car sit idly without being used, the battery will slowly keep draining. This is because even when your car is not in use, it is still pulling power, especially if it is a high-end car that is equipped with a lot of smart gadgets.

It is probably common knowledge about batteries that they rely on an electrochemical reaction to produce power. In car batteries, electricity is produced when electrons flow from the anode to the cathode, mediated through a sulphuric acid solution that functions as the electrolyte.

When your car is sitting idle, this chemical reaction continues to take place but at a slower rate. However, the longer you let it sit, the more the battery discharges. Depending on how new the battery is, the discharge may take longer. But if it is a high-end car, it may lose charge within two weeks if it is not used.

This is where the job of an alternator comes in. The alternator works like a generator that keeps your battery running. When the car is revved up, the alternator supplies electricity to the car battery and the chemical reaction that was draining its charge is reversed.

But what one must remember is that the alternator cannot revive a battery that has already lost charge. It can only maintain the power of the battery, for which the car needs to be in use consistently.

How to Charge a Phone in Car without Draining Battery?

Typically, charging your phone through your car should not drain the latter’s battery, unless the car battery is old and has very little reserve charge left. Your car battery is arguably a lot more powerful than an average smartphone’s battery. So even if you plugged your phone into a running car, it is very unlikely that the device can drain your car battery unless it is already old and nearing discharge.

Having said that, it would be advisable to remove the charger from the cigarette port when it is not in use. The fewer devices you have plugged into your car, especially if it is going to stay idle for a prolonged period.

How to Listen to Radio without Draining Car Battery?

The radio does not draw as much power from your car battery, perhaps only a few amps, which is nowhere near enough to kill a healthy battery. As long as the battery is well maintained, charged regularly through consistent use and has not corroded, you can listen to the radio in the car without affecting the battery.

Does Using Cigarette Lighter in Car Drain Battery?

If your cigarette lighter is still on even when the ignition has been shut off, then yes, it can continue to drain your car battery. Most manufacturers make it so that when the car is powered off, the electricity supply to the cigarette lighter is also cut off. Check with your manufacturer to see if the socket for the cigarette lighter is wired directly to the battery. Ideally, that should not be the case.

Can Alternator Drain Battery When Car Is Off?

If the alternator is faulty, it can most certainly drain even a new car battery out. If the diode of the alternator has corroded or damaged, it may continue charging the circuit even when the vehicle is off. This, in turn, may cause the battery to be drained even if you have recently installed a new one.

To check if the alternator has gone bad, pop the hood of the car and start the ignition. Remove the negative cable from the battery while the car is still on. If the engine gets cut off, that is an indication that your alternator is not generating enough current to keep the engine running by itself.

Can Jumpstarting a Car Drain Your Battery?

If your car battery has drained from sitting idle for too long, at times jump-starting may help to revive it. However, if you do not jump start the vehicle correctly, it could cause permanent electrical damage, not only to your own car but also to the vehicle of the person jump-starting yours.

When jump-starting a car, whether your own or someone else's, always ensure that you hook the cables on the right poles. Also, ensure that you are using good-quality cables and that they are at least 6 gauge.

Can Emergency Lights Drain Car Battery?

Emergency lights are a very common reason for cars to be drained over their battery overnight or within a few hours. In fact, if you accidentally leave any lights in your car on, whether the headlights, taillights, or the hazard lights, it can zap even a new battery off its power.

So, when you turn off the car and retire for the day, ensure that all the lights are turned off.

Frequently Asked Questions

There may be several more technical questions about preserving your car’s battery. The following sections will attempt to answer some of those questions:

Should You Disconnect Car Battery When Not in Use?

If a car battery won’t be in use for over two weeks, then it may be advisable to disconnect the batteries to preserve its juice. If you have a planned vacation coming up or if you are going out of town for work, disconnecting your car battery may prevent the frustration of having to jump start a dead battery when you return.

Can Excessive Heat or Cold Drain a Car Battery?

Yes, extreme weather can have an effect on your car’s battery. A car battery can go up 140ºF or higher during extreme heat, which can cause the battery fluids to evaporate and damage the battery. On the other hand, if the climate is very cold, it is natural for life, in general, to slow down. The same happens to your car battery. The chemical reaction that keeps the battery charged becomes much slower when the weather is cold.

What Can You Do to Protect the Car Batteries from Weather Extremities?

In both cases, the best thing is to park your car in a garage or under a shed where the weather extremities will affect the vehicle less. You should also get your batteries checked before the weather takes a turn so a dead battery does not catch you by surprise.

Will Putting a Car Battery on the Ground Drain It?

The only thing that will drain your battery is age, temperature and prolonged idleness. That car batteries drain if they are placed on concrete or cement is a myth, though they emerge from earlier wooden casings of batteries that could swell up from moisture on the ground and cause the fluid to leak. Today’s plastic packaging and leakage preventing seals, however, will ensure this does not happen. The only thing you need to concentrate on is that you should not leave your battery idle for too long, whether you put it on the ground or leave it unused in your car.

About the author, Phil Borges

Phil Borges is a battery aficionado. He's written extensively about batteries, and he loves nothing more than discussing the latest innovations in the industry. He has a deep understanding of how batteries work, and he's always on the lookout for new ways to improve their performance.