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Discussion Starter #1
Draining the battery.. I've had this happen twice while camping. Leaving the rear hatch open seems to drain the battery. I've turned the only door lights switch off i can. My first trip i had a tent opening attached to the hatch for 4 days. Tried to start the car after that and the battery was totally dead. I figured i had left some cords plugged into the USB ports and maybe that drained the battery. 2nd time was for a single night. Nothing plugged into the USB ports. The battery wasn't dead but there was that delay starting which I've seen before when the battery is lower than normal. I camp enough and leave the rest hatch open regularly. Not sure what i need to do to preserve the battery? (Touring).
 

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When the gate is up I noticed set of lights by the 2nd row center console cup holders. And a second set under the nav screen in front of the gear selector. Haven't figured out how to turn these off. I would think these lights is what killed the battery.
 

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I'm assuming with the gate up you had the keys either in the car or close to it. Doesn't it say somewhere that that will drain the battery on the push button start vehicles? No idea how long that would take though...
 

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Discussion Starter #4
I'm assuming with the gate up you had the keys either in the car or close to it. Doesn't it say somewhere that that will drain the battery on the push button start vehicles? No idea how long that would take though...

Yes, I remember reading that about draining the battery. But not having the fob inside the car would be problematic. Even disabling the fob first would be a problem because the hatch is really the only convenient way to get in and out when sleeping. (I'm not as young as I used to be :tango_face_wink:). This is a tough one to test again because my garage doesn't allow an open hatch and I don't have a readily available way to jump the car if the battery was dead. I had this happen with my Outback and it was determined that one cell of the battery was not working. I'm really not thinking that is the same thing here. Just wondering if anyone else leaves their hatch open for extended periods and what happens. Actually thinking I might change the lights to LEDs to cut power drain if it happens (although I'm not fond of how bright and white the lights are for this application). This is one of those things where you can't easily take it into the service center and they can see the problem immediately!
 

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Yes, I remember reading that about draining the battery. But not having the fob inside the car would be problematic. Even disabling the fob first would be a problem because the hatch is really the only convenient way to get in and out when sleeping. (I'm not as young as I used to be :tango_face_wink:). This is a tough one to test again because my garage doesn't allow an open hatch and I don't have a readily available way to jump the car if the battery was dead. I had this happen with my Outback and it was determined that one cell of the battery was not working. I'm really not thinking that is the same thing here. Just wondering if anyone else leaves their hatch open for extended periods and what happens. Actually thinking I might change the lights to LEDs to cut power drain if it happens (although I'm not fond of how bright and white the lights are for this application). This is one of those things where you can't easily take it into the service center and they can see the problem immediately!

1. For your drained battery - https://www.amazon.com/gp/product/B078T9P8LS/ref=s9_acsd_topr_hd_bw_b1MrSyp_cr_x__w?pf_rd_m=ATVPDKIKX0DER&pf_rd_s=merchandised-search-6&pf_rd_r=MMEV4YY49448B11BX15C&pf_rd_r=MMEV4YY49448B11BX15C&pf_rd_t=101&pf_rd_p=f8b794fc-fc0a-5594-9fa2-492188c338ef&pf_rd_p=f8b794fc-fc0a-5594-9fa2-492188c338ef&pf_rd_i=1253955011


2. For your Key Fob - to block it signaling the car so the light will go off: https://www.amazon.com/Faraday-Blocking-Keyless-Antitheft-Protector/dp/B077XTMHZW/ref=sr_1_4?s=automotive&ie=UTF8&qid=1535225972&sr=1-4&keywords=faraday+bag+for+key+fob&dpID=61DXbZcuomL&preST=_SY300_QL70_&dpSrc=srch


Both items have lots of excellent reviews.
 

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I feel like the logical solution to your problem is to disconnect the battery while you're camping. If you need to charge phones or whatever, you can reconnect the battery and start the car or buy something similar to the Anker 20,000 mah power bank I use. It'll charge my phone (Galaxy S8+) 4 times...which is enough for over 2 weeks for me while I'm out in the backwoods.
 

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Discussion Starter #7
Thanks, guys. I know there are workarounds. I have had a battery jump starter for camping and I have battery power banks for phones and the like. What I'd really like to figure out is what is draining the battery so I don't always have to plan to have those things along. :) When we desert camp, we often see no one and for those times, I am prepared with all the important tools. We usually take our old 4Runner on those trips with our camping trailer. First camping trip in the Ascent was me alone with relatives (backup) nearby. Last weekend was a little more impromptu with one night out trying two people sleeping in my car - just to see how it works. Still testing out the vehicle to see what works and what doesn't and I hate having to worry about leaving the hatch open and draining the battery. This is when I wish it had a roll down back window like the 4Runner - perfect for camping! I'm also posting this so others might be aware and report back if they have similar issues.
 

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Leaving the door open will typically leave one or more body control modules active which will keep the communication bus awake. Essentially keeping the vehicle ready for whatever the occupant wants to do. However with many OEMs a timeout is present to avoid excess battery drain. My guess is one or more modules are staying fully powered and not going to their quiescent state. These problems are typically found during CAN bus testing, but maybe there is a reason it is this way.

You could simply find the hatch open sensor and rig it closed when needed, however it may be built into the latch, I'm not familiar with the Ascent's yet. Looking at the parts and cable harness diagrams could help.
 

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I would disconnect the battery personally. Doing deep discharges of your battery is not going to be good for it’s lifespan.
 

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I wrote to SOA regarding the dead battery issues when leaving the tailgate up. I thought I would share their response and advice (read chrono order from bottom up):

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Re: Battery issue with Lift Gate up

Thanks, Kelly. Tailgating would be out of the question, though, if the battery issue can’t be resolved ? I will check with the dealer, but this seems more like a design issue that engineers might want to look into. Appreciate the response!

Sent from Karen's iPhone

On Sep 17, 2018, at 7:54 AM, Subaru of America, Inc. <[email protected]> wrote:

Dear Ms. Martin,

Thank you for contacting Subaru.

We appreciate you taking the time to email us. *Having any door open for a period of time will have an impact on the vehicle's battery. *We do not recommend that you keep any door open. *Your Subaru retailer is in the best position to offer any advice on a technical inquiry. *Please give the Service department a call for this type of advice.

We hope that you are enjoying your Ascent! *If tailgating is in your future, we hope that you will consider shopping some of the Subaru gear, https://subarugear.com/Productlist.aspx?did=22123

Best wishes,

Kelly
Subaru of America, Inc.

[THREAD ID:1-GNTIP2R]

-----Original Message-----

From: *[email protected]
Sent: *9/14/2018 03:42:27 PM
To: *[email protected]
Subject: *Battery issue with Lift Gate up

Several folks online are reporting dead batteries when leaving the rear lift gate up for tailgating, camping, etc., even with NO visible lights left on. Is there a way to disable whatever is running the battery down with the gate up? I want to go camping and tailgating with mine but am afraid to get stranded. Thanks in advance for any solutions you might have.
 

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Hmm this is interesting as someone who goes camping I typically leave the hatch open for a bit till we get everything out and unpacked. I think Subaru might want to test how long the hatch can be open before the battery runs down.
 

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I'm in the same boat, although we only go camping a couple times a year. We tend to leave the rear hatch open at times.
 

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If you leave it open for the tent kind of thing, then I'd look for something to keep the switch pressed so the Ascent thinks the door is closed. Shouldn't be too hard to do!

Also, might want to get a 10w or so solar car battery topper too. I have one that keeps a battery topped up so I can have a fan in my shed to keep it cooler here in the desert.
 

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For tailgating/camping, a remote installed kill switch might be your best option. The cheap alternative is just disconnecting the battery when you park. The remote cutoff will allow you to restore the connection quickly though, if you want to turn the car on for some reason.

Example:
https://www.summitracing.com/parts/prf-30206?seid=srese1&cm_mmc=pla-google-_-shopping-_-srese1-_-painless-performance&gclid=Cj0KCQjwrZLdBRCmARIsAFBZllFL6VGeUVZSXAuVM3kDwbHyhuVJfshaXEXsAJMeKwqQq1c6PgRaHJcaAvWgEALw_wcB
 

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I was watching MCM on Youtube recently where their 2 cars kept having battery draining issues over long periods so they installed this:

Battery Master Disconnect Switch.

It has to be installed on the negative terminal. YMMV.

The video:

 

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Discussion Starter #17
I was watching MCM on Youtube recently where their 2 cars kept having battery draining issues over long periods so they installed this:

Battery Master Disconnect Switch.

It has to be installed on the negative terminal. YMMV.

The video:

How To Install a Battery Isolator (EASY & CHEAP!)

I like this! Simple and easy. I can see myself doing this over pulling off the battery cable. No tools, no mess to disconnect. Found one on Amazon for $11. Even if I don't install it now, I think I'll pick one up for that odd time when you find your hatch is going to be open for an extended period of time.
 

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For those that suggest simply disconnecting battery, there's the big issue of being able to open rear gate. I went camping this summer and had the battery die because the rear gate was open too much. Had I disconnected the battery, I wouldn't have been able to open the rear gate at all, which I probably did 40 times. When camping, you're constantly putting things in and out of car, leaving the campsite then coming back, going to bed, etc. So unlike tailgating you've got to be able to open all the doors regularly, which disconnecting the battery prevents.
 

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For those that suggest simply disconnecting battery, there's the big issue of being able to open rear gate. I went camping this summer and had the battery die because the rear gate was open too much. Had I disconnected the battery, I wouldn't have been able to open the rear gate at all, which I probably did 40 times. When camping, you're constantly putting things in and out of car, leaving the campsite then coming back, going to bed, etc. So unlike tailgating you've got to be able to open all the doors regularly, which disconnecting the battery prevents.
Which is the purpose of having a kill switch. The disconnect option is only if you don't want to spend money. There are battery kill switches ranging from inexpensive ($10), up to full remote install kits that you mount in the cabin (I've seen upwards of $300 for a nice kit). The remote install kits are pricey, but much more convenient and usually very well built.
 

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When you disconnect your battery, doesn't that mean your car goes back into "relearn" mode with the ECU each time you connect again?
 
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