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Posting this here since it may be useful. This is a cross-post from the Subaru Ascent Dead Battery FB Group: Subaru Ascent Dead Battery Club : Guys the problem is DEFINITELY NOT the tailgate

Guys the problem is DEFINITELY NOT the tailgate!!! My dealer found that my Ascent had a parasictic current draw of 300mA. The parasitic draw while everything is closed and off is supposed to be around 20mA!!! It makes perfect sense too. With a battery that is rated at 55AH, that means that after 7.6 days of not driving it, the battery would be totally discharged. This is what we're all struggling with, our batteries are just barely staying alive enough to start and then as soon as we turn on the accessory or open the tailgate, that puts it over the edge and the battery is toast.

Event if you do drive your vehicle daily, it may not be enough to charge the battery more than the parasitic draw took while the car was unused!

With a normal parasitic draw of 20mA, a 55AH battery would technically go for 114days without dying.

I'm convinced that this is actually the issue most people are experiencing and it actually has nothing to do with the tailgate. Yes the tailgate uses too much current and doesn't turn off after a while. But even with a 3amp draw on the tailgate, on a fully charged 55AH battery, you should be able to keep it open for 18hrs before completely draining the battery.

The reason it appears to us like the tailgate is the problem is that yes, the tailgate does use too much current, and we always have the car off when opening the tailgate (unloading groceries, etc), but this is just the point when the battery goes from already being nearly dead (from many hours/days of excessive parasitic current draw), to completely dead and unable to start the car.

I've also noticed that my Ascent couldn't start after just 1 minute of listening to music in accessory mode, which makes perfect sense after learning what I just described above.

So what's the steps to solve?
  1. Get a trickle charger and/or a portable booster (so that you're temporarily safe from being stranded)
  2. Get your dealer to diagnose and fix your parasitic current draw. Tell them that it may be a faulty solenoid. The draw may be ~300mA when it should be only ~20mA.
  3. Get your dealer to replace your battery free of charge. Yes the Ascent battery may barely good enough, but with no excessive parasitic drain, you technically don't need a bigger/upgraded battery if the root problem is fixed.
 

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Posting this here since it may be useful. This is a cross-post from the Subaru Ascent Dead Battery FB Group: Subaru Ascent Dead Battery Club : Guys the problem is DEFINITELY NOT the tailgate

Guys the problem is DEFINITELY NOT the tailgate!!! My dealer found that my Ascent had a parasictic current draw of 300mA. The parasitic draw while everything is closed and off is supposed to be around 20mA!!! It makes perfect sense too. With a battery that is rated at 55AH, that means that after 7.6 days of not driving it, the battery would be totally discharged. This is what we're all struggling with, our batteries are just barely staying alive enough to start and then as soon as we turn on the accessory or open the tailgate, that puts it over the edge and the battery is toast.

Event if you do drive your vehicle daily, it may not be enough to charge the battery more than the parasitic draw took while the car was unused!

With a normal parasitic draw of 20mA, a 55AH battery would technically go for 114days without dying.

I'm convinced that this is actually the issue most people are experiencing and it actually has nothing to do with the tailgate. Yes the tailgate uses too much current and doesn't turn off after a while. But even with a 3amp draw on the tailgate, on a fully charged 55AH battery, you should be able to keep it open for 18hrs before completely draining the battery.

The reason it appears to us like the tailgate is the problem is that yes, the tailgate does use too much current, and we always have the car off when opening the tailgate (unloading groceries, etc), but this is just the point when the battery goes from already being nearly dead (from many hours/days of excessive parasitic current draw), to completely dead and unable to start the car.

I've also noticed that my Ascent couldn't start after just 1 minute of listening to music in accessory mode, which makes perfect sense after learning what I just described above.

So what's the steps to solve?
  1. Get a trickle charger and/or a portable booster (so that you're temporarily safe from being stranded)
  2. Get your dealer to diagnose and fix your parasitic current draw. Tell them that it may be a faulty solenoid. The draw may be ~300mA when it should be only ~20mA.
  3. Get your dealer to replace your battery free of charge. Yes the Ascent battery may barely good enough, but with no excessive parasitic drain, you technically don't need a bigger/upgraded battery if the root problem is fixed.
Many owners have asked their dealer to figure out why their batteries have died. SOA is very aware of the complaints so they have depending on the specific symptoms a detailed step by step diagnostic procedure in place. My question is two fold. What specific diagnostic step did you dealership take that led that to determine it was a parasitic draw and did they determine where it was coming from? Other dealers have looked into the draw and have NOT found a high parasitic draw. I recall a post that tested the draw before and after the tailgate controller was replace and it went down significantly to being negligible, so in that case it was in fact related to the tailgate.
 

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Posting this here since it may be useful. This is a cross-post from the Subaru Ascent Dead Battery FB Group: Subaru Ascent Dead Battery Club : Guys the problem is DEFINITELY NOT the tailgate

Guys the problem is DEFINITELY NOT the tailgate!!! My dealer found that my Ascent had a parasictic current draw of 300mA. The parasitic draw while everything is closed and off is supposed to be around 20mA!!! It makes perfect sense too. With a battery that is rated at 55AH, that means that after 7.6 days of not driving it, the battery would be totally discharged. This is what we're all struggling with, our batteries are just barely staying alive enough to start and then as soon as we turn on the accessory or open the tailgate, that puts it over the edge and the battery is toast.

Event if you do drive your vehicle daily, it may not be enough to charge the battery more than the parasitic draw took while the car was unused!

With a normal parasitic draw of 20mA, a 55AH battery would technically go for 114days without dying.

I'm convinced that this is actually the issue most people are experiencing and it actually has nothing to do with the tailgate. Yes the tailgate uses too much current and doesn't turn off after a while. But even with a 3amp draw on the tailgate, on a fully charged 55AH battery, you should be able to keep it open for 18hrs before completely draining the battery.

The reason it appears to us like the tailgate is the problem is that yes, the tailgate does use too much current, and we always have the car off when opening the tailgate (unloading groceries, etc), but this is just the point when the battery goes from already being nearly dead (from many hours/days of excessive parasitic current draw), to completely dead and unable to start the car.

I've also noticed that my Ascent couldn't start after just 1 minute of listening to music in accessory mode, which makes perfect sense after learning what I just described above.

So what's the steps to solve?
  1. Get a trickle charger and/or a portable booster (so that you're temporarily safe from being stranded)
  2. Get your dealer to diagnose and fix your parasitic current draw. Tell them that it may be a faulty solenoid. The draw may be ~300mA when it should be only ~20mA.
  3. Get your dealer to replace your battery free of charge. Yes the Ascent battery may barely good enough, but with no excessive parasitic drain, you technically don't need a bigger/upgraded battery if the root problem is fixed.
A better solution would be buy another product (vehicle) that does not have this issue.
 

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Mine can sit in the garage for days on end, even a week at at time, and not have the battery go dead. 2020 Ascent Premium.
 

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2020 Ascent Touring
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Mine can sit in the garage for days on end, even a week at at time, and not have the battery go dead. 2020 Ascent Premium.
For our '20, a week is typical, 2 weeks frequently and several times 3 weeks with no issues starting. Haven't even broken 2000 miles in 10 months due to pandemic (and Ascent isn't our daily driver).
 

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If memory serves me correctly, Subaru only has one battery across every vehicle it sells.

In other words, I've been led to believe that the Impreza shares the same battery as the Ascent.

This....doesn't sound right at all.
 

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If memory serves me correctly, Subaru only has one battery across every vehicle it sells.

In other words, I've been led to believe that the Impreza shares the same battery as the Ascent.

This....doesn't sound right at all.
While the battery may not be the most robust in that size category, it was the parasitic draw from the Ascent that was the problem. The QC of the battery manufacturing was also an issue at times. I am not sure whether the defect rate was above Subaru spec or not. Many auto manufacturers use the same battery manufacturer.
 

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Many auto manufacturers use the same battery manufacturer.
Indeed, however I doubt other manufacturer's use literally the same battery SKU. This is my understanding - that all batteries are literally the same active SKU in the Subaru lineup.
 
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