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Bad news from the Facebook dead battery forum.

There are two separate reports of the power lift gate controller TSB failing to reduce the draw after 20 minutes on 2019MY with build dates of 07/18 and 9/18.
 

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My Ascent (2018MY) battery died on Friday, Oct9. Completely flat. Zero volt. The car was in front of my house, everything closed and locked. This is already fifth time since April.
Interestingly, first 18 months this was not an issue.
I managed to jump-start with my "Imazing" jump starter, but it took 5-6 attempts. I completely killed it.

Couple days ago I wrote email to [email protected] with all my complaints - and still got no answers.

Anyone got any responses from subaru customer care re battery?
 

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^^^ were any of the dome lights accidentally left on? That happened to me.
 

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Bad news from the Facebook dead battery forum...There are two separate reports of the power lift gate controller TSB failing to reduce the draw after 20 minutes on 2019MY with build dates of 07/18 and 9/18.
I just re-verified the drain on my Mar 2019 build Premium post TSB and it started at 2.2A and was down to a few tens of mA after 20 minutes. That's with all doors closed and TG open, all lights out and fobs far away. I used two different clamp-on ammeters being careful with zeroing and orientation.

I should try a few more permutations, like bring a fob close, open and close a door, turn some interior lights on, etc...and see what effects those have.
 

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Yeah. That's what I saw when I did a test that was from fully charged. Still trying to wrap my head around the 85% to 65% drop - my best guess is that my battery charger is simply using the OC voltage to estimate the percentage, and for whatever battery-curve-chemistry reason, it decided it was a 20% drop that time.

Today I did a much more systematic test from full.
Voltage at full was 12.84V (Charger read "maint / full")
I wanted to test the doors vs the lift gate timeout. (To confirm the doors have the same (or better) 20 minute timeout.)
Draw was 3.0 amps for the entire time. (Puddle light in door, 4 dome lights in the back, front two dome lights off, rear hatch lighting off)
After 20 minutes the draw dropped.
Voltage then read 12.72V
I then hooked up my charger and it listed it at 92%
So * shrug * -- Not quite 20% -- but also not quite 3%
Batteries are weird.
When a significant load is placed on a car battery, you will read a voltage drop during the load and after it's removed. The battery voltage may often seem to have dropped precipitously. However, give the battery a few minutes to recover from a short-term load, and the voltage level will usually bounce right back. So, you're right, batteries are weird. lol
 

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The rear passenger ones can be turned on permanently buy pushing on them. They'll then stay on. I accidentally bumped one loading some stuff and pfffft, dead battery two days later.
 

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Bad news from the Facebook dead battery forum.

There are two separate reports of the power lift gate controller TSB failing to reduce the draw after 20 minutes on 2019MY with build dates of 07/18 and 9/18.
One of those people didn't test, the other concerns me. I asked that person to confirm with the dealership that they completed the 20 minute power consumption test. Never heard back.
 
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