Well I changed the battery monday evening and the only thing I had to do was reset the auto windows and change the tire pressure monitoring system from kPh to PSI. Now, two days later, ALL the radio preset disappeared. What a system.

 

Well only a week later the new battery paid off. I left the cargo light on last night and 10 hrs later I came outside and "Casper" started right up with NO issues. 2019 Outback Touring 3.6R

 

My experience with a dead battery on our 2 year old 2015 2.5 Outback with 36000 miles was that when the car started with the new battery the motor would not idle...kept dying when I took my foot off the gas. After driving around for awhile it still idled rough, but did not stall. The windows and tire monitors had to be reset. The dealer said it was due to the computer putting the throttle body back to the factory default position where it did not compensate for crud that had formed around the throttle plate, thus giving a bad idle. For the next time I pulled the battery, I purchased a VSTM OBDII memory cable through Amazon, which luckily I tested before hooking it up. It did not put volts to Pin #16, but instead was hot to a pin which might have caused damage. The company directly replaced the cable with one that now was now hot to another incorrect Pin. They did give me a full refund and did not want the faulty cables back.

 

I'm surprised nobody has recommended using a set of jumper cables hooked to another battery and the terminals of the Outback while swapping batteries. That one usually sparks some interesting conversations and drama.

 

Well, there is a non-trivial risk of doing something extremely dangerous (but I did use that method once out of curiosity).

 

This is an interesting conversation. I've had my battery go dead - leaving inside lights on - twice!! I don't recall what did not work when I charged the battery and restarted the Outback, but I had to take it to the dealer both times to reset the rear lift gate and the windows - as I recall. I bought a memory saver that plugs into the OBDII port - have not used it, but hope it works when I change my battery - which is working fine. Now I'm thinking, I wonder if I need the OBDII memory saver?? Just hope it works when I need to change the battery.

 

Ok, I changed the battery and did not bother with the memory saver. Nearly everything worked. I did have to reset the windows but that was not too bad. The only other thing I noticed was the tire pressure monitoring system is now reading in kPh instead of PSI. Nothing else on the vehicle changed to metric but that one item. Someone must know how to change it back but I cannot find it in the owners manual. I am sure there is a good reason why a vehicle manufactured in Indiana would default to metric only on the tire pressure. Go figure.

 

Turn the car on (don't start it), then you have options in the steering window view panel, one of the options is to set the metric system of everything except the tire pressure, and the next option is to set the tire pressure metric system

 

Window reset for 5th gen is easy, just roll each window all the way down, holding the switch down for another 5 seconds or so after window is down, then roll the window back up, holding the switch again for another 5ish seconds after the window is up. Repeat for each window, and done.

I don't bother with a battery saver either, just swapped the new batter in, reset the windows and the couple options in the menus that changed, and was all done in less than 5 minutes (windows included). Didn't need to re-pair phone or anything like that.

 

Ok, I replaced the battery today and did not use the memory saver. Radio presets are ok. I have to dig out the manual and go thru the window reset dance. Now only the drivers window works from the drivers door and it does not work on AUTO. Tire pressure is in metric but I am sure I can find how to change that eventually. Oh well I should have known. Once again I got what I paid for. It only makes sense for a car manufactured in Indiana to default to metric ONLY on the tire pressure. I hope that engineer got a raise.

 

It only makes sense for a car manufactured in Indiana to default to metric ONLY on the tire pressure. I hope that engineer got a raise.

I heard he got an extra 100 yen/hour for that one.

 

Yeah, I've had mine disconnected several times and no issues. My trip odometers were reset and I had to re-initialize the windows, but that's it. According to the 2015 FSM, there are a variety of additional things which should be checked, but I've never seen any reports of problems here in the Gen 5 subforum. Two of the items detailed in the FSM are easy enough you might as well address them - throttle and idle adjustments. As @Rymar mentioned, after reconnecting the battery, you put the ignition in the ON position without starting the engine. Leave it there for at least 10 seconds for the throttle to complete adjustment. Next, start the engine and make sure no additional loads are present (lights, AC, etc). Without touching the gas pedal, let the engine idle until fully warmed up. They say the engine is fully warmed up when the radiator fan has activated at least twice. I've never bothered monitoring the fan - seems it can sometimes take quite a long time to activate, and who wants to stand there waiting. I've just always had the car well warmed up before disconnecting the battery. Then, after reconnecting, I simply let it idle for 15 minutes or so and call it good.

 

I recently changed my battery on my 2014 3.6. I also thought they needed a memory tender. The guy at autozone said they don't and he was right. Didn't even have to mess with the power windows.

 

Seems like a bunch of wasted effort and expense. I swapped the battery in my wife's '17 Forester without any sort of memory saver. The only things that needed resetting were the power windows, a whole 15 seconds, and the radio presets, another 30 seconds.

 

You may have a point, but this is an interesting electronics experiment. I learned a bit about how my car’s electrical system works, and some time is saved for those who have the tools readily available. Here is what I did:

How to change battery without your OB noticing!

The attached pics show my OB without a battery, but the car does not know the battery is gone. The silly car is so gullible. 1. Turn off the car’s electronics as much as possible (e.g., doors closed, all lights off, etc.) 2. Prepare the external 12V power supply. Another car battery will do...

www.subaruoutback.org

 

Group Size 24 Battery

Bosch Platinum Series AGM Battery Group, Size 24 (PepBoys on sale ) Perfect fit, no alterations required. (did not use sleeve) Make sure of terminal location. (24 NOT 24F ) 9 Volt Battery Powered OBD ll Memory Saver (Amazon) Did not lose settings.

www.subaruoutback.org

Worked for me.

 

I left a Battery Tender connected via its hardwired pigtail when changing the battery. Thought I was being smart. Started the car for the first time with new battery and it thought it was a Legacy. But no radio or door lock settings were lost. Trip odometers were reset.

Next time I started the car it properly knew it was an Outback.

I don't think the Battery Tender worked. I don't think it was necessary.

 

I left a Battery Tender connected via its hardwired pigtail when changing the battery.

A good quality battery tender will detect that there's no battery present and then discontinue charging. That's how it's designed to work.

A charger with a separate "supply" mode (like the CTEK 7002) will do what you want, as will just about any low-ripple, regulated, 12 volt power supply.

 

I have had the battery disconnected in my 2019 Outback Limited 2.5 with 8" HU (nav) multiple times, and there is really nothing which needs to be backed up. The HU keeps all its settings, as do the seat memories. The only thing you will need to do is retrain the 2 front windows for auto-open/auto-close: drop to halfway, and then close and hold for about 1 second. Note that the driver's side control for the passenger window will not work at all until you retrain the passenger window right at the passenger door.

The only other thing to be aware of is that it will take a few drive cycles until the OBD "readiness monitors" are all set, but that only would affect a state smog inspection.

Also, there is a note in the users manual about waiting 10 seconds before starting the car, since the throttle plate controller needs to run a self-calibration. Haven't noticed this one though. The car runs fine after a battery disconnect as well; I haven't noticed any idling or other driveability problems after each battery disconnect.

So, no need for battery backup.

 

My jump starter has a lead that plugs into the OBC port. It works

XP-10 MICRO-START Jump-Starter

Top Rated, Best selling XP-10 is unrivaled for performance & quality in the mini jump-start segment. Start DIESELS and gas engines. Charge all your devices.

antigravitybatteries.com

 

I am looking at the ones with 9V battery that plug into cigar lighter socket. I know I would need to keep the car in the ACC position. I have a small battery jump starter but I would have to connect to the existing cables at the battery and I am concerned it could become disconnected during the change out. Thank you for your suggestion.

 

I am looking at the ones with 9V battery that plug into cigar lighter socket. I know I would need to keep the car in the ACC position.

That's not going to work, since all three 12 volt accessory sockets are downstream of (i.e. isolated from the battery bus by) a relay (Accessory Relay 2).

 

I used a 9V Battery with alligator clips. It maintained the settings while switching out the battery.