How Do You Start A Subaru With A Dead Battery

Subaru Outback Battery Drain Fix, Reset&Drainage Prevention

Last updated on December 14th, 2022 at 11:43 am

Subaru outback battery drain fix: As a motorist, you might have experienced turning on your vehicle with your key; but it doesn’t start, or nothing happens when you try to do just that! 

Naturally, you could blame a drained or dead battery for this problem. Though batteries are one of the essential components of your Subaru Outback, what could have caused the battery to die or drain at first? 

Could it have been a parasitic drain, battery corrosion, faulty alternator, or loose terminals? In this contemporary time, Subaru outback batteries significantly discharge and recharge thousands of times in their lifetime. 

Although, if your Subaru’s battery dies or keeps dying after several charges or does jump starts, it is best to replace it entirely and likely reset your Subaru outback to avoid issues with the electrical system. 

This article will expound on additional topics, such as; where is the Subaru battery drainage prevention function, why does my 2019 Subaru outback battery keep dying, the Subaru outback battery drain fix and reset, the Subaru outback battery drain reset guide, and more.

Subaru Outback Battery Drain Fix

Where Is The Subaru Battery Drainage Prevention Function?

The Subaru battery drainage prevention function is at the door or rear gate. If the door or rear gate is adequately closed, the interior lights of your Subaru will be on. Nevertheless, the battery drainage prevention function helps to prevent the battery from draining.

It’s crucial to close all doors and the rear gate entirely before leaving your Subaru.

Why Does My 2019 Subaru Outback Battery Keep Dying?

Although, the Subaru Outback is prone to battery issues which can leave you stranded on the roadside if you need to know the causes of these issues.

Here are a few reasons why your 2019 Subaru outback keeps dying;

Faulty Alternator

Having a good connection between other parts of your 2019 Subaru outback and the battery, but the battery is not functional, a lousy alternator should be the problem.

From my experience as a certified mechanic, the alternator might have gone bad internally due to wear and tear, or even louse bearings, and needed to be changed. Similarly, the alternator could have been functional without a lousy accessory belt or damaged pulley.

Corrosion Of Battery

The chemicals that store electricity inside the battery release small amounts of gases that react with battery terminals.

The build-up of this reaction might cause an electrical interruption to the vehicle’s system, keeping your 2019 Subaru outback from starting. Always clean this corrosion with a wire brush to get your battery working again!

Battery Needs To Be Replaced Completely

Your 2019 Subaru outback has a range battery life of about 3 to 5 years. This time frame could be affected by mileage and extreme weather conditions (very hot or cold). So, if your battery has lasted up to 4 to 5 years, you should replace it with a new one.

How Long Do Subaru Batteries Last?

The Subaru batteries have a lifespan of about 5 years at most. Nevertheless, this time could depend on factors like; how often you drive and extreme temperature conditions. Although, if you move your Subaru more often, the battery will last longer than someone who doesn’t. The most appropriate way to extend your battery life without mixing words is to drive your Subaru more often.

Why Does My Subaru Battery Keep Dying?

Though having a dead battery automatically means you don’t have access to your Subaru. Hence, your Subaru battery keeps dying because of these;

  • Your Lights left On: When you leave your lights on, your battery will slowly die/ drain. So, it required you put them off.
  • Short, Intermittent Drives: Your Subaru battery keeps dying if you aren’t driving long enough, allowing the alternator to perform its function. Embarking on a long-distance trip could be positive for the alternator’s functionality.
  • Extreme Weather Conditions: Your battery could also die when your environment’s temperature is boiling and freezing. That said, hot weather heats the battery to death, and freezing weather can freeze the chemicals and make to die fast. Check your batteries if you live in areas with the atmospheric conditions mentioned above.

Why Does My Brand-New Battery Keep Dying?

The reason why your brand-new battery keeps dying over and over again is due to the following issues;

  • Parasitic Drain
  • Loose Battery Terminals
  • Bad Battery Cells
  • Infrequent Driving
  • Bad Alternators 

One or two or all issues combined could facilitate your battery dying as quickly as. However, it is necessary to turn off the electronic components of your vehicle before you exit it.

Subaru Outback Battery Drain Fix And Reset

To reset the system of the Subaru Outback is to disconnect the terminals that connect the battery.


  1. Access the battery close to the firewall
  2. Then take off the cover made of black plastic material
  3. Disconnect the negative and then positive terminals a few minutes later.
  4. At about 15 minutes, reconnect the cables as you make clamps tight.

However, you could also use a scanner to reset your car battery on your Subaru outback. The scanner is plugged into the OBDII port to reset your system. I recommend you get a certified technician to do this safely and correctly.

Subaru Outback Battery Drain Fix, How To Guide

Resetting your Subaru outback after a battery change requires the steps below;

Step 1: Establish what needs to reset as you check the dashboard for any warning lights.

Step 2: Ensure to check all connections are for effective reset.

Step 3: Allow components that reset automatically to do so efficiently.

Step 4: Make new settings that are required manually.

Step 5: Ensure the effectiveness of all your manual settings. You could also use the above procedure in the Subaru outback battery drain reset guide.

Subaru Outback Battery Drain Reset Guide

How Do You Stop A Car Battery From Draining When Not In Use?

When your car battery is not in use, the following ways are essential to keep it from draining.

Disable the parasitic drain by disconnecting all security systems and adequately closing the trunk, glove box, and doors.

  • Use the battery maintainer (automatic battery charger) to charge/recharge and check the optimal amount of power in the battery.
  • Disconnecting the negative terminal of the battery will prevent battery drain.
  • You could remove the battery from your vehicle and store it in a place with a temperature of about 40 to 60 degrees Fahrenheit.

What Is Draining My Car Battery When It’s Off?

Significantly, the malfunctioning of some electrical components which were wrongly installed could have drained your car battery when it is off. So this kind of drain is called parasitic battery drain and is persistent until your battery is empty of any charge. Your battery might also drain when it’s off if it has reached the end of its service life.

What Drains A Car Battery Overnight?

The faulty or lousy electrical system is the leading cause of the overnight draining of your battery. Hence, it is called a parasitic drain. A wiring short (malfunctioning electronic) component or any aftermarket accessory installed improperly might cause a parasitic drain. Similarly, the parasitic drain will continue to drain current from the battery system even after you remove the keys and lock the doors as your vehicle is parked.

How Do You Start A Subaru With A Dead Battery?

There are two methods of starting your Subaru when the battery is dead.

  1. Push to start
  2. Attaching jumper cables to another car’s battery (jump-starting).

These methods are effective for manual and automatic transmission vehicles, respectively. And if the battery procedure discharges after each technique, you must replace the battery with a brand-new one.

Push To Start

Although, two or more persons are needed to start your Subaru with a flat battery. You will drive while others will push.


  • Put the ignition on to start your Subaru.
  • Place your Subaru on the second gear as you press down the clutch pedal.
  • You should push the car as fast as possible.
  • Allow the clutch pedal quickly as the speed increases.
  • As the vehicle moves abruptly, press the clutch pedal again to help the engine as the accelerator presses.
  • Keep it on for a few minutes to enable the battery to charge again.

To Start With Jumper Cables

To do this effectively, get proper jumper cables for batteries having a crocodile clip.


  • The cars should be close, but they shouldn’t have contact as you turn them off. Make sure the dead battery car is in the park position.
  • Make one end of the red jumper cable clamp to the positive terminal on the flat battery and connect the other end to the positive terminal of the active battery.
  • Similarly, connect the black jumper cable clamp to the negative terminal of the active battery and then the other end to any metallic piece of the car with a dead battery, away from the battery.
  • Start the car with the active battery as you leave the engine to run for a few minutes without moving.
  • Then start the car’s engine with the flat battery as you leave the machine to run.
  • Eventually, the car with a flat battery stops working; you should accelerate up to 1500 to 2000 RPM.
  • If the idle speed of the flat battery’s engine becomes routine, you should disconnect the negative and positive terminals later.
  • Allow the car at idle speed to run for a few minutes as you move it to an average speed to check if it will turn off. Doing this will charge the battery again, and you are good to go!

Can A Car Battery Go Dead From Sitting?

Unfortunately for you, your car battery can go flat or dead if you haven’t used it for weeks (at least two weeks) or months as it has nothing to charge it.

Although, the instructions below should help preserve your battery’s life as your vehicle is sitting or parked for a long time. Secure it in a garage as you disengage the security system, disconnect the negative terminal, and charge the battery weekly as you drive for at least 30 minutes.


Does Subaru Use AGM Batteries?

Of course, Subaru uses AGM batteries, especially the Subaru forester. The AGMs (Absorbent Glass Mat) batteries are more powerful than most traditional lead-acid accumulators since they can withstand draining and recharging many times.

How Much Does It Cost To Replace The Subaru Battery?

The cost of replacing your Subaru battery depends on the Subaru model. Still, a range cost is between $45 to $750 for an average Subaru, and for Subaru hybrids, the battery could cost between $800 to $1000. Though, the costs stated excludes labor cost and taxes.

How Often Do Subaru Batteries Need To Be Replaced?

Knowing that batteries don’t last forever, the frequency at which you will need to replace Subaru batteries is on, how well you care for them, the quality of the battery, and how often you drive. You can replace your Subaru batteries performing the above functions at most after 5 years.

When Should A Subaru Battery Be Replaced?

Without mixing words, you should replace a Subaru battery once you notice that it is no longer functional as supposed, if it has stopped holding electric charges, or when there is significant corrosion of the terminals/connectors, which could lead to electrical issues. You should know that nothing endures forever; replacing when you observe the above signs is crucial. 

How Many CCAs Does A Subaru Outback Need?

The number of Cold Cranking Amps (CCAs) needed by any Subaru outback would depend on the year. Hence Subaru outback needs 600 CCAs on average but could have a range of 390 to 850 CCAs in their battery requirements.


To wrap up this post, experiencing battery issues as a Subaru outback owner has been disheartening.

Although, these problems, such as a bad alternator, loose battery terminals, parasitic drain, bad battery cells, infrequent driving, and more, have led to the draining of your battery. 

So far, it is evident that batteries don’t endure forever, but maintaining and caring for them will make them last beyond expectation. Though, the average lifespan of Subaru batteries is 4 to 5 years at most. 

To research and study, the best way to make the battery last longer is to drive your vehicle often as you avoid the extreme temperature of freezing and hot weather. 

I think you should follow the instructions above as you greatly increase the efficiency of your Subaru outback battery and also consult professional mechanics to help you when necessary. Do like and share this informative article with others!


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