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Why Does My Subaru Battery Keep Dying?

Updated: Aug 25, 2021

So many changes have taken place in the last 6 months and one huge change for many of us has been how often we use our vehicles. Some of us are now working exclusively from home, relying on delivery for everything from dinner to door knobs, which means our cars are spending much more time in the driveway or garage. Others might have gotten back into the work force and are commuting for longer periods of time, or maybe you've been feeling cooped up in the house and have joined many other people on the road who are out just to take a drive, with no real destination in mind.

No matter how your driving patterns have changed, you might have experienced some issues with your Subaru not starting or needing a few tries before the engine fires. Of course there can be numerous reasons for a Car Not Starting, but often times it is an issue with the Battery that is keeping you from hopping in your Subie and getting on the road.

Modern Car Batteries are designed to discharge and charge back up again thousands of times over its life. A Subaru Battery that Suddenly Dies and keeps dying after multiple charges and jump starts usually needs to be replaced. If not, there could be a variety of other issues with the Subaru system that keeps your Battery Charged as you drive. Here are six of the most common reasons your Subaru Vehicle's Battery might be Repeatedly Dying.

  1. Battery Needs To Be Replaced

  2. Short/Intermittent Drives

  3. Battery Corrosion

  4. Faulty Alternator

  5. Parasitic Drain

  6. The Weather

Battery Needs To Be Replaced

On average, most Car Batteries will last about 5 years, but of course the life of your Subaru Battery can vary for many reasons. Cars that spend their lives in extreme weather areas with very hot or very cold temperatures will need to have the Batteries replaced much more frequently than in places with mild, dry climates. If you're not sure if your battery needs to be replaced, The Subaru Guys can easily perform a Battery Health Diagnostic Test to determine if your Car Battery is still viable, or if a New Battery is needed. Reincarnation Inc. strongly recommends purchasing a New Battery if your current Battery is more than 5 years old.

Short/Intermittent Drives

Your Car Battery is just one part of your Vehicle's Charging System. As you drive, a component called the Alternator turns the mechanical energy generated by the engine, into electrical energy that recharges your Car's Battery. Longer time spent on the road, helps the Alternator to do its job properly. If your diving habits have changed, and your Subaru is spending more time in the driveway than on the road, you might consider taking the scenic route from time to time to help your Battery and Alternator function optimally. The extra drive time will allow the Alternator to charge the Battery longer, giving you more charge in the Battery for the next time you attempt to start your vehicle.

Battery Corrosion

Battery Corrosion is caused by hydrogen gas being released from the sulfuric acid inside the Battery. As the gasses react to the ambient atmosphere, it begins to produce a corrosive environment. Other elements such as moisture and salts also accelerate the process. The result is a blue-ish, green-ish or grey-ish, powdery substance that builds up on the Battery Terminals. A build-up of Corrosion on the Terminals of your Car's Battery can interrupt the Battery Connection to the rest of the system, preventing your Subaru from starting properly.

Faulty Alternator

If your battery itself is healthy, but isn't being recharged as you drive , you could still find yourself stranded with a Dead Battery. Usually this means your Alternator is bad. Early warning signs of a Faulty Alternator can include Engine Stalling, Electrical Malfunctions, Abnormal Noises, Dim or Flickering lights, and Difficulty Starting the Engine. If the Alternator can't convert power generated by the engine into usable electricity, your car will use up all the power left in your Battery until it dies.

Parasitic Drain

It might sound like something from a horror movie, but Parasitic Drain is a common problem for Subaru Owners. Of course, your Battery may drain overnight if you leave your interior dome light or head lights on. But even if you turn everything off, your Battery may die overnight due to malfunctions in the electrical system. This is called Parasitic Drain. Parasitic Drain will continue to draw current from the Battery, even as the car is parked. A wiring short, a malfunctioning electronic component or an incorrectly installed aftermarket accessory could also result in Parasitic Drain.

The Weather

In New Mexico we tend to have pretty decent weather, especially in the winter, but any fluctuation in temperature can effect the performance of your Subaru or any Import Vehicle. Cold weather is especially hard on Car Batteries. According to AAA's Automotive Research Center, at 0°F, a Car's Battery loses about 60 percent of its strength and at 32°F it loses 35 percent. During cold temperatures, starting an engine can take up to twice as much current as needed under normal conditions. It is very common for us to see Vehicles coming into the shop during the Spring and Fall with Battery issues because of the extreme temperature fluctuations we see here in New Mexico during these two seasons.

If your Subaru Battery has been giving you issues or you just need a Reputable Mechanic in Albuquerque to give your Subaru the green light for Overall Vehicle Performance and Road Safety, give Reincarnation Inc. The Subaru Guys a call today or visit or website .

Our award-winning team will be happy to Diagnose your Subaru for you and keep your Import Vehicle happily on the road for years to come.


Reincarnation Inc.

The Subaru Guys

1300 2nd Street NW Albuquerque NM 87102


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