Battery dies if the car sat for over 20 hours
Since I purchased the car, I had to get the battery replaced over ten times. It just keeps dying. I had the battery load-tested and it checks out fine as well as the alternator. However, each battery dies if a day goes by that I don't drive the car. I was told that I had to drive it every day so as to prevent the battery from getting drained. There are no dash warnings nor error codes. Only the MAP light that occasionally comes on and won't turn off the car even when the engine is off. What could be causing the battery to die out so quickly?
Experienced mechanics share their insights in answering this question :
Batteries that drain overnight are common. Usually when this occurs, there is a parasitic drain on one of the car’s systems. When this occurs it drains the battery down over time. Batteries that are drained down repeatedly can cause them to fail. The most common causes of the battery drain are aftermarket accessories, radio, power windows and seat motors. If you can find the cause of the parasitic drain, a certified mobile technician from YourMechanic can come to your car’s location to diagnose your battery and determine what should be done.
How to Identify and Fix Common car Problems ?
Our sources include academic articles, blog posts, and personal essays from experienced mechanics :
Why Your Car Battery Keeps Dying. While car batteries slowly die over time, high heat, brutal cold, excessive use of vehicle accessories (after-market equipment), and other mechanical issues can shorten the life of even the toughest battery.
But when the engine is off, the alternator can`t recharge the battery, allowing little electrical mishaps to drain your battery entirely. The battery strain caused by these electrical whoopsies is known as a parasitic draw.
Most car batteries have a capacity of 45 Ah and a vehicle electrical system voltage of 12 volts. So if you have left the interior car lights on all night and two small bulbs with 10 watts continue to burn, the battery will only be empty after 27 hours.
Interior lights, headlights, stereo accessories, and other electrical components can cause a Volvo draining problem. If your car won`t start, double-check to make sure you`ve turned off all accessories.
“Electrical devices or lights left running, a defective charging system or alternator, and extreme weather are some common reasons but maybe it`s just time to get a new battery.”
This happens when something – a glovebox light, an amplifier, any electrical component – is pulling power from the battery when it shouldn`t. Since the alternator isn`t generating vehicle electricity, the problem component pulls from the battery, slowly draining it overnight until your vehicle won`t start.
No a burnt fuse can`t cause battery drain issues. Some fuses don`t get power until the circuit is turned on so don`t be concerned about them. Has your battery been replaced or load tested to make sure it`s good? A weak battery can make it seem like you have a draw.
An effective method to determine whether it`s your battery or alternator that`s gone bad is to connect jumper cables from a running vehicle`s battery to yours. After a few moments, try starting your vehicle. Once it`s started, remove the jumper cables — if your engine stalls, your alternator has probably gone bad.
Battery Overuse
If you tend to leave your headlights on, for example, your battery will only be able to power these lights for so long before running out of charge. Do I need a new car battery? In these cases, you should not need a new battery after you jump-start.
Leaving Your Headlights on
One of the fastest ways to cause a battery drain is to leave your headlights on for long. If your car battery keeps draining, there`s a chance that you have formed the habit of leaving your lights on even when parked. Most times, your headlights stay on until the battery dies down completely.
Using a test switch and digital ammeter is the simplest, most accurate way to measure parasitic drain directly. A test switch goes between the negative battery terminal and negative battery cable.
If you often get “LOW BATTERY” warning despite regular long drives, you can disconnect the cable at Battery Monitoring Sensor (BMS) for 20 seconds.
Contrary to its purpose, an alternator can drain a battery. It`s rare, but it`s possible. A draw on the battery only occurs if there`s a problem with either a component in the alternator itself or connections to it.
If you take your vehicle to an auto parts store they may give you a new battery for a few hundred dollars, without running any tests. Don`t make this mistake! A faulty alternator could ruin a perfectly healthy battery, which would put you further back from a solution than where you started.
It is possible that the drive belt has broken or come off the pulley, or the tensioner went bad completely. Alternators put out alternating current, and the battery needs direct current to charge, so there is a voltage rectifier that converts it, and it can suddenly go bad, too.
How long can a car last on just the battery? If your alternator fails when you`re far from home, you can typically drive up to 200 miles on battery power alone. That`s assuming your battery is in good shape and fully charged. Of course, it`s best to get the alternator repaired or replaced as soon as you can.
Set your multimeter to DCV (DC Volts) above 15. Make sure your alternator`s positive and negative terminals are clean. Put the multimeter`s black cable to the negative terminal and the red cable to the positive terminal. Look for an ideal alternator reading of around 12.6.
Disconnecting your battery and draining the power to cause an ECU reset is one of the most common fixes for a check engine light that won`t go away on its own. Doing so is equivalent to a hard reboot on a desktop computer, which is a standard way to eliminate many common problems.
The exact amount of time that your car will be able to function with the battery light on depends on many factors, but assuming that the alternator is the issue (this is the most common issue) it is likely that your car will lose battery power after 30 minutes to an hour of driving.
An early warning sign that your alternator is going bad could be dim, flickering lights. This symptom could show up on any or all of your dashboard lights, reading lights, headlights or other lights. The alternator is supposed to provide the electricity for your car`s lights.
When you`ve left the lights in your car or headlights on for a long time without the car running, it tends to drain your car`s battery. A car`s battery gets recharged when it`s on the move; that`s why you can charge your phone, listen to music, and even turn on the headlights and interior car lights.
Electrical Fault
Any short within your car`s wiring can cause draining issues. The alternator could also be a culprit. Battery usage seems infinite when you`re driving down the road, and that perception is thanks to the alternator.
When you leave the lights on for an extended period of time when the car is off, the battery continues to power that component. Since the car is not running, it can`t recharge. That`s called parasitic draw (also parasitic drain).
Relevant Questions and Answers :
the most relevant questions and answers related to your specific issue
Battery dies if the car sat for over 20 hours
ANSWER : Batteries that drain overnight are common. Usually when this occurs, there is a parasitic drain on one of the car’s systems. When this occurs it drains the battery down over time. Batteries that are drained down repeatedly can cause them to fail. The most common causes of the battery drain are aftermarket accessories, radio, power windows and seat motors. If you can find the cause of the parasitic drain, a certified mobile technician from YourMechanic can come to your car’s location to diagnose your battery and determine what should be done.
Read Full Q/A … : Battery dies if the car sat for over 20 hours
My car will not start Intermittently. I purchased a new battery 2 weeks ago and yesterday the car wouldn’t start. Got a jump and
ANSWER : The issue you are having is probably due to an intermittent fault in the starter motor itself or a deficiency in the starter electrical circuit, for example a large voltage drop due to a poor ground or a high resistance connection. These issues can be readily diagnosed and resolved on a mobile basis if you request a hard starting diagnostic. If you request that diagnostic, the responding certified mechanic will get this resolved for you promptly. Based on Toyota’s Factory Service Manual, the battery should not be disconnected if the vehicle engine is running. The battery acts as a large resistive voltage sink and consequently taking the battery out of the circuit, while the alternator is still running, can create a voltage spike on the car’s electrical system which is not good for voltage sensitive components such as the engine computer. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.
Read Full Q/A … : Battery dies if the car sat for over 20 hours
Car died while driving so I replaced the alternator and battery and car won’t attempt to turn over. What else could it be?
ANSWER : The initial failure was likely caused by a sudden fuel system (e.g., failed fuel pump) or electrical (including ignition) faiure. Prior to performing diagnostics be sure you have a fully charged battery that passes a load test. Then, confirm that the engine immobilizer system (security system) is not activated thus preventing the car from starting. If the starter motor is not functioning, check for power to the starter motor when the key is held in the "start" position. If there a large voltage drop at the starter motor or no power at all, you may have a faulty ignition switch but you do have to check out the entire starter circuit, which includes grounds, wiring (some of which is very heavy cabling), fuses, relays, the ignition switch and terminations. On the other hand, if the starter motor is getting power but the starter doesn’t work, then the starter is condemned and replaced. If you desire that a certified mechanic resolve this, please simply request a no start diagnostic and the responding certified mechanic will get the problem diagnosed and repaired for you. Please let us know if you have further concerns or questions as we are always here to help you.
Read Full Q/A … : Battery dies if the car sat for over 20 hours
When changing the car battery, do you "register" the battery to the car computer?
ANSWER : Hi there. Changing the battery has nothing to do with programming a battery. If the car was flat dead with a battery that lost all of the power because the dome light was on, then when jumped the vehicle will run fine. What may need programmed when the battery is replaced is the key fob. The key fob will lose programming to the computer as the vehicle computer is reset. However, if a 9 volt battery saver was put into a cigarette lighter and the car battery was removed, then the computer will not lose its memory and be just fine. If you need further assistance with your battery, then seek out a professional, such as one from Your Mechanic, to help you.
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Water was spilled in the trunk which soaked the car battery. Car won’t start now. Does water destroy a car battery?
ANSWER : Hi, thanks for writing in about the concern with the BMW 320i. If the battery was submerged in water then it’s completely possible for the battery to short out and die. Your friend will need to have the battery replaced. Also be sure to get all of the water out of the trunk. Have a certified technician, like one from YourMechanic, help you guys out if you need assistance with replacing the battery. Good luck.
Read Full Q/A … : Battery dies if the car sat for over 20 hours
My battery light is on.
ANSWER : The problem is not the battery, but the charging system is not keeping the battery recharged. The alternator is the most common cause of this, though failing battery cables can also be a cause. I would recommend having the battery cables and alternator tested and checked by a mechanic, like one from YourMechanic, who will come to you and diagnose the problem for you. Do not try and drive it or it will leave you stranded from the battery going dead again. The cables to the battery from the alternator may be bad or the alternator is not charging. Only the testing and diagnosis will reveal the problem.
Read Full Q/A … : Battery dies if the car sat for over 20 hours
New battery & fuel pump. Hours later car starts and shuts down 3X in a row. Finally it starts, 48 hours later, won’t start at all
ANSWER : Checking all the fuses was a good move. I would also want to put a scan tool on it and check for diagnostic trouble codes (DTCs) as well as seeing the data that the computer is seeing.
A fuel pressure test would be a good idea to verify correct pressure and so that you’d be able to eliminate that possibility. It should be 58psi on your Magnum.
I also recommend getting your battery tested (I know, it’s new, have it tested anyway) and be sure it’s charged to at least 75%. And yes, loose battery cable connections can result in electrical problems.
If you need some assistance with this, consider enlisting a certified mechanic who can perform the checks I’ve mentioned and diagnose your starting issue firsthand. The mechanic can then perform the necessary repairs once the problem has been isolated. Good luck.
Read Full Q/A … : Battery dies if the car sat for over 20 hours
Car battery dying quickly especially after longer driving
ANSWER : It sounds like the alternator is not charging the battery, when are you driving long distances. Running all the accessories and then shutting it off can cause the battery to be too weak to restart the car. If the alternator is intermittently not charging, then you may have other wiring issues or just an intermittent problem within the alternator. Have the charging system checked by a mechanic after driving it and not shutting it off, to see if the battery is being charged. You may also have a body control module issue with extended storage mode. The dealer can check this mode with the special scanner and checking the extended storage fuse is not installed.
Read Full Q/A … : Battery dies if the car sat for over 20 hours
