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Discussion Starter · #1 ·
Battery completely drained after a week on vacation. The Ascent was in the garage all week and this morning I tried to start it for the first time since before we left, NOTHING then I realized there was lights, the battery must've gone dead or enough where it won't start the car. The car was left unlocked so I was able to open the car. I don't recall leaving any lights on in the interior. The only thing that I had added to the car was the dash cam but that shuts off with the car.

Obviously it can't be moved out of the garage thanks to the awesome push button, so I put on my Battery Tender and left for work in my Chevy Silverado (did not have any issues). Both vehicles were left for about a week but the Chevy started right up, with the same dash cam setup.

Anyone else encounter this? I wonder if it's something in the car or probably just a weak battery to start with.
 

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Battery completely drained after a week on vacation. The Ascent was in the garage all week and this morning I tried to start it for the first time since before we left, NOTHING then I realized there was lights, the battery must've gone dead or enough where it won't start the car. The car was left unlocked so I was able to open the car. I don't recall leaving any lights on in the interior. The only thing that I had added to the car was the dash cam but that shuts off with the car.

Obviously it can't be moved out of the garage thanks to the awesome push button, so I put on my Battery Tender and left for work in my Chevy Silverado (did not have any issues). Both vehicles were left for about a week but the Chevy started right up, with the same dash cam setup.

Anyone else encounter this? I wonder if it's something in the car or probably just a weak battery to start with.

I was going to ask the same questions. The fob can cause drain if it is too close. I also turn off my dome "door" light because it caused me grief in my Outback and I do have times where I leave the hatch or door open. However, I did have a low battery that caused me problems. Left the hatch open while camping, battery died. Then a couple of other things. Last straw was listening to the radio on ACC for no more than 10 minutes and the battery was so low I had a hard time starting it. I took mine in and they said low battery - "possibly leaking". They replaced my battery.
 

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did you leave a key fob inside/near the car?
I see people asking this quite a bit for this vehicle. I wonder why that is? What is so different about the Ascent over other Subaru vehicles?

For reference, I have a 2017 Impreza, same type of fob. I garage that vehicle and leave the fob in the car. It stays in there for 12hrs at a time, everynight. I have gone on vacation for more than a week leaving the car to its lonesomeness and never had a problem starting or battery draining. My Ascent is not garaged and the fob is within I'd say 12' during the evening. Yet I read horror stories of dead batteries while people camp overnight and attributing it to sleeping in the vehicle with the fob? Really? Something else must be up, and I hope that I am not wrong.
 

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I see people asking this quite a bit for this vehicle. I wonder why that is? What is so different about the Ascent over other Subaru vehicles?

For reference, I have a 2017 Impreza, same type of fob. I garage that vehicle and leave the fob in the car. It stays in there for 12hrs at a time, everynight. I have gone on vacation for more than a week leaving the car to its lonesomeness and never had a problem starting or battery draining. My Ascent is not garaged and the fob is within I'd say 12' during the evening. Yet I read horror stories of dead batteries while people camp overnight and attributing it to sleeping in the vehicle with the fob? Really? Something else must be up, and I hope that I am not wrong.
The key fob and car are communicating when they're in proximity to each other, which uses power (not a lot, but it does use power). It is more of a long term issue than an over night or few days issue, but if combined with an already low battery, could cause it to drain the battery completely.

We had a Volvo V90 that constantly drained batteries (its a 2017, never sold, and we want it gone very badly, if anyone is interested). We discovered that the valet key fob was locked in the trunk in the display box. We took it out and haven't had issues since. I don't know that it is for sure an issue with the Ascent, but it is an issue with other vehicles (especially in combination with other factors).
 

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The key fob and car are communicating when they're in proximity to each other, which uses power (not a lot, but it does use power). It is more of a long term issue than an over night or few days issue, but if combined with an already low battery, could cause it to drain the battery completely.

We had a Volvo V90 that constantly drained batteries (its a 2017, never sold, and we want it gone very badly, if anyone is interested). We discovered that the valet key fob was locked in the trunk in the display box. We took it out and haven't had issues since. I don't know that it is for sure an issue with the Ascent, but it is an issue with other vehicles (especially in combination with other factors).
It isn't so much the power the key takes for the communication with the vehicle but that the communication bus in the vehicle will be awake at some state and that can keep other body control modules and modules awake, depending on the setup. If you have a bunch of CAN transceivers talking, even with their modules mostly "off" it can drain a good amount of power.
 

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The key fob and car are communicating when they're in proximity to each other, which uses power (not a lot, but it does use power). It is more of a long term issue than an over night or few days issue, but if combined with an already low battery, could cause it to drain the battery completely.
To me, "communication" is happening regardless of proximity. You have something that is constantly speaking, like the car saying (Fob? Are you there?) and then is constantly listening for a response. The fob, is also constantly speaking, (Here I am, car!). Each of which uses power. When the car gets an initial response due to proximity, it doesn't stop asking if the fob is there. It still checks. It is just waiting to acknowledge some human interaction to see if that human action is permissible. Can it unlock doors? Can it open the lift gate? Does it acknowledge the push button start 1x? 2x? with foot on brake? That is really about it.

So I would go back to bad battery, doors open, lights on, button stuck on fob, ACC on, approach lights on, wifi hotspot on, or something else.

Maybe it is a conspiracy.....get everyone to Amazon Subscribe and Save the NOCO GB40 Jump Starters?
 

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To me, "communication" is happening regardless of proximity. You have something that is constantly speaking, like the car saying (Fob? Are you there?) and then is constantly listening for a response. The fob, is also constantly speaking, (Here I am, car!). Each of which uses power. When the car gets an initial response due to proximity, it doesn't stop asking if the fob is there. It still checks. It is just waiting to acknowledge some human interaction to see if that human action is permissible. Can it unlock doors? Can it open the lift gate? Does it acknowledge the push button start 1x? 2x? with foot on brake? That is really about it.

So I would go back to bad battery, doors open, lights on, button stuck on fob, ACC on, approach lights on, wifi hotspot on, or something else.

Maybe it is a conspiracy.....get everyone to Amazon Subscribe and Save the NOCO GB40 Jump Starters?
That is true, but not the full story of how it works. To keep listening for the Fob that module can run on its own without the rest of the CAN bus being "awake" (more importantly waking other modules); and that near field communication can be pretty cheap given the duty cycle and power needed. However once the key is in proximity the CAN bus is "awake" and other modules are in various state of lights, locks, preparing to start or go to on/accessory, etc. If the key is left in proximity the system should have a timeout if no button is pressed, etc., however it could still be in a partially awake state.

The same is true when you unlock your car with a non-keyless fob, the vehicle's modules start waking up to be prepared, lights turn on, etc.

It all comes down to the timeouts and decisions they make to handle different conditions. I would tend to agree that the lights would be my first culprit to check as the 2nd and 3rd row lights are easily left on by kids and don't have the door control.
 

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I see people asking this quite a bit for this vehicle. I wonder why that is? What is so different about the Ascent over other Subaru vehicles?

For reference, I have a 2017 Impreza, same type of fob. I garage that vehicle and leave the fob in the car. It stays in there for 12hrs at a time, everynight. I have gone on vacation for more than a week leaving the car to its lonesomeness and never had a problem starting or battery draining. My Ascent is not garaged and the fob is within I'd say 12' during the evening. Yet I read horror stories of dead batteries while people camp overnight and attributing it to sleeping in the vehicle with the fob? Really? Something else must be up, and I hope that I am not wrong.
Sitting overnight with the fob in the car is not something that's going to kill the battery of the car in and of itself. But what that WILL do is end up reducing the life of the battery in your fob, so instead of lasting 4 - 5 years, it'll probably die in 2 - 3.

We've replaced a fair number of batteries in Outbacks with new batteries. I will not make a comment regarding my personal opinion of the OEM Outback battery ... you can draw your own conclusions simply based upon that refusal. :devil:
 

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Discussion Starter · #10 ·
Could have been a bad battery from the manufacturer, did you leave a key fob inside/near the car?
Nope, i took the fob with me. Can't think of anything.. I will check with the batter tender when I get home in a few hours to see if I can start up the car.

Thanks for all the responses... I'll update with what I find. I'm guessing no one has gone a week or more and left the car unattended.
 

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Discussion Starter · #11 ·
Sitting overnight with the fob in the car is not something that's going to kill the battery of the car in and of itself. But what that WILL do is end up reducing the life of the battery in your fob, so instead of lasting 4 - 5 years, it'll probably die in 2 - 3.

We've replaced a fair number of batteries in Outbacks with new batteries. I will not make a comment regarding my personal opinion of the OEM Outback battery ... you can draw your own conclusions simply based upon that refusal. :devil:
Hmm, I should get the battery tested for output. Or, just take it in and have them change it - I hope they don't try to give excuses and try to avoid changing the battery.
 

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I left my car for 8 days and had no problem restarting it when I returned. I had my car only 2 weeks at that point.
 

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The other thing to keep in mind is that even if YOU don't have anything turned on, guess what? Subaru Starlink is still on. Your security system is still on. So there will be some parasitic drain on the battery all the time. I don't know how much there actually is, but I know it's still happening.
 

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My car was off for a week today when I started it it took a bit longer to crank, but it did start. It does seem that all the electronics drain the battery a bit faster than most other cars. If it th weather was in the 30's I don't know how well it would have started. I'll have to monitor mine and see how it does as the temperature drops.
 

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This is a bit disturbing if it is a widespread problem. We should not have to worry about how long we park or if it is too cold. Not sure I like the thought of going on a long vacation this winter only to arrive back at the airport to find my battery is dead
 

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This is a bit disturbing if it is a widespread problem. We should not have to worry about how long we park or if it is too cold. Not sure I like the thought of going on a long vacation this winter only to arrive back at the airport to find my battery is dead
If it's too cold, it doesn't matter, you're looking at a dead battery regardless of what you're in. Go through a January where the high temperature is -5 and see how much fun it is.

But this isn't seen as a problem, per se. This is also something that's becoming common across the brands, not just with Subaru, as more and more electronics are added to vehicles. Battery tenders that plug into cigarette lighters and help trickle charge things are common in the RV industry - I suspect they're going to get more common in the auto industry as the more electronics trend continues.
 

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Starlink essentially turns off after 14 days to conserve battery. Most cell systems in cars do that. OEMs want their cars to last 30 days or more sitting still and still crank over in the winter, off current is a very important requirement for all components.
 

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Discussion Starter · #18 · (Edited)
Ok.. i know why the car is dead! The wife left one of the rear lights on! lame.. I had to push it out of the garage to jump it with my truck because the Battery Tender didn't work. Basically every time it charged up the light would suck it dry.. LOL.

I also learned that you have to use a screwdriver to unlock and engage the shifter in order to get it out of drive into Neutral. Nice to know since these cars have Push Start and isn't obvious.
 

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Ok.. i know why the car is dead! The wife left one of the rear lights on! lame.. I had to push it out of the garage to jump it with my truck because the Battery Tender didn't work. Basically every time it charged up the light would suck it dry.. LOL.
Good to know, still wish they were controllable by door (or remain off) and would timeout.
 

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Discussion Starter · #20 ·
Good to know, still wish they were controllable by door and would timeout.
I know.. my coworker was giving me a hard time cause his 1990's Ford is more reliable has a shut off timer in case the light was left on. Lame o Subaru. Another thing they could fix.
 
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