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Why Does My Car Keep Dying With A New Battery?

car keeps dying with new battery

Why Does My Car Keep Dying With A New Battery?

Typically, every electrical component of your car should be turned off before you exit your car. But, sometimes you could end up exiting the car without ensuring every light and electrical component is switched off.  Such human errors might be the major cause of a drained car battery.

If you just got a new battery for your car but noticed that it gets drained easily, here are likely reasons behind it. First, leaving the headlights on, not closing the trunk properly, and leaving some internal lights on. If the car stays overnight with these functionalities active, the battery gets drained, and your car won’t start.

To explore every possible reason why your car keeps dying with a new battery, make sure to continue reading.

Seat And Door Control Module

a set of car keys
Source: Pixabay

When you notice your car is constantly dying due to battery problems and can’t trace where the problem stems from, then look at the seat and door control modules because it might be causing your car woes. Specifically, your control module can drain your battery when there’s a short circuit that extracts so much power from it, leaving it drained. 

The seat and door controls need sufficient power from the battery to function properly. Hence, if the power drawn by the seat and door control modules from the battery becomes insufficient, it’ll drain the battery. Your car’s battery will also get drained if the seat and door controls are not well grounded. Thus, your car will not start or gradually die off. 


Take your car to a qualified mechanic to fix it properly. But if it’s still under warranty, take it to the car dealer’s shop to fix it quickly and prevent further damage to the electrical system. 

An Open Trunk

open car trunk
Source: Unsplash

If you leave your trunk open for a long time, your new car’s battery will discharge completely, and your car will not start. The reason is that the trunk light is very bright, and your battery will drain faster than when a dome light is left on. 


Promptly close your trunk properly once you are done with it. Disconnect your car battery if you want to open your trunk for a long time. Doing this will turn off your trunk light completely to avoid battery drainage. 

Defective Alternator 

cambelt in car
Source: Unsplash

The alternator is responsible for recharging your car battery and powering certain electrical systems, such as all the lighting systems, air-conditioning, radio, and automatic windows. If the diode in the alternator is bad, your battery won’t charge; hence, it’ll drain. Moreover, a defective alternator diode will result in circuit charging even when the engine is off, and your car won’t start because of a dead battery. 


Once you discover a defective alternator, take your car to a good mechanic’s workshop to diagnose and fix it. If your car cannot make it to a workshop, you can invite an auto expert to your residence. Or hire a tow van to tow your car to the mechanic’s workshop. 

Headlights And Some Internal Lights Were Left On 

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When you forget to turn off the car’s headlights and other internal lights, they’ll draw power from your battery and deplete it. However, some modern car brands will signal you once any light is on, but it may fail sometimes. 


Prioritize putting off every light before you lock your car. That will save you unnecessary stress from car issues. Plus, you won’t have to spend some extra bucks on a drained battery.

Defective Charging System

jump start car
Source: Pixabay

Candidly, your car’s battery can drain even as you’re driving. The car is designed to power all the light systems and radio from the alternator, which can drain the battery if there’s a charging problem. Also, the alternator may have loose belts or worn-out tensioners that’ll hinder your charging system from working properly. 


Examine the alternator belt to ensure it’s tight and functioning properly. Then, check the alternator voltage output using a voltmeter. If it is below 13.5 v, the charging system is defective. Send your car to an expert auto mechanic immediately to fix the charging system and avoid further damage. 

Parasitic Drain

man driving car
Source: Unsplash

Just like it sounds, a parasitic drain happens when electrical components in your vehicle continue to run after the key is turned off.

Your battery gives energy to your clock, radio, and security alarm to keep functioning optimally. However, if there’s an electrical problem due to bad wiring, bad installation, or faulty fuses, the parasitic drain can exceed the normal, and the battery will get drained. 

Furthermore, if the headlights, interior lights, and taillights aren’t switched off, they’ll drain your battery by drawing power from it even when your engine is switched off. 


Switch off every light and electronic gadget before you alight from your car. Remember to fix every electrical fault (bad wiring, bad switches, and wrong installations) that will draw power from your battery and deplete it. You can visit a qualified mechanic to diagnose your car and fix it properly. 

Extreme Temperatures 

extreme weather conditions
Source: Unsplash

Extreme temperatures can affect the car’s battery. If the temperature is extremely hot, measuring above 100 degrees, or too cold, measuring below 10 degrees, it can cause the build-up of lead sulfate. If the car stays long in this condition, lead sulfate can damage your car’s battery and will take longer to charge, especially when you drive short distances


Regularly check the battery charge and top it up occasionally. Additionally, make sure your battery is clean and free of corrosion. Watch out for these signs during winter. Ultimately, send it to an auto repair shop to fix it appropriately. 

Final Words

checking fuses
Source: Pixabay

It’s frustrating to have a car that keeps dying with a new battery. Discovering the root cause can be tricky, but it all boils down to being more careful about those minor components that operate in the background.

If you’re currently experiencing this problem, quickly request the assistance of a qualified mechanic to diagnose and repair your car properly. 

Why Does My Car Keep Dying Even With A New Battery?

If your car keeps dying with a new battery the issue is likely to stem from a loose or corroded battery, extreme weather conditions, parasitic drains, or a defective charging system.

How Do I Find Out What’s Draining My Car Battery?

You can examine your car battery with a multimeter to determine if it’s charged or not. Once you can ascertain a battery issue, look for possible causes like a defective charging system and parasitic drains. Also, check if you mistakenly failed to turn off any lights.

What Kills A New Battery In A Car?

A new car battery may die if you leave your headlights and internal lights on for a long time when you idle or drive too many short distances. A defective alternator and charging system can kill your car battery.

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