[Snap]

Just a couple gripes for consideration.
Looking in our manual for the battery size for replacement, I came upon a paragraph that claims the car will shut down certain lighting circuits if the battery is being discharged too much when the car is shut off. Then I wonder why I have had to recharge our 3 year old battery 3 times in a month. and how is it a car battery can't run a dome light overnight? I have flashlights that can beat that.

Before I read about the claimed automatic light shut down, I wondered how a company, that designs all kinds of electronic aids for drivers who may not be quite up to the challenge, can't make a stationary car's system shut down ALL things that can kill the battery for it gets past the point of no return. Wouldn't that make more sense?

The other related issue is that on the last required recharge, the charger tested the battery as 75%. When the key was turned, beep, beep, click, click.
A Subaru starter is inoperable at 75% battery juice. Really? Something is wrong with that.

It seems these cars aren't as smart as the marketing tries to make them appear.

 

[RadcomTxx]

Batteries can crack internally, preventing them from developing current, even though a voltage reading may say “75%”

 

[Botnik]

I'm not sure how much Subaru shuts down with the engine off. I'm used to cars in which if you turn the key from "on" back to "accessory," you can sit there and listen to the radio as you wait for whatever you need to wait for. Then you start the car up and go. In my 2007 Forester, if you turn the key from "on" to "accessory" the heated seats are still powered! Duh. And in my 2018 the stereo has a big touch screen and when the ignition system is in whatever state it's in before the engine is running (I have push button start), it seems like the battery is powering the entire Google server farm behind the dashboard, so I'm scared to sit and listen to music as I wait. And in the 2018, while the rear heated seats are turned on by momentary switches, and the seats power down when you shut the engine off, the front heated seats are powered through the same type of rocker switches as in the 2007.

 

[Snap]

I'm not sure how much Subaru shuts down with the engine off. .

They list what is supposed to be shut down in the '15 owners manual; some lights.

 

[Even_Stephen]

The problem isn't with Subaru's "battery saver" design. The problem is with Subaru's awful factory batteries. You are lucky you got 3 years. Go get a new battery, but not from Subaru.

 

[Botnik]

My 2007 OEM Subaru battery lasted 9 years with daily stereo usage with the key in the "accessory" position. I don't change my batteries until I'm unable to start the car. With that 9 year old battery it took a half second or so to start the car, and I changed the battery only because I was going on a road trip and didn't want to get stuck in the states. If I were going to stay in my home city, I would just use the battery until the car wouldn't start, and then I'd call my wife to come pick me up, we'd go to the shop and buy a battery, and she'd drop me back off at my car and I'd change the battery and go home.

 

[Yoda_One]

Why???? It is a normal maintenance item, low cost and can be a safety issue. I usually replace batteries around 3 years and keep the old ones for emergencies or give them away to individuals that could use them. I also tender all my batteries once a month including the extra ones. During the last hurricane they were a life saver keeping my phone charged and use them with invertors to have lights and coffee.

Laughing at oneself and with others is good for the Soul

 

[Botnik]

Why did I use my battery for so long? Because there was no reason to change it. And the only reason I changed it was for extra confidence that I wouldn't be stuck in the states. The main purpose of the battery is to start the car, and there was no problem doing that. I guess another purpose for the battery would be to run the hazard lights or the radio in an emergency. In some systems the battery could also be used to smooth out the voltage from the alternator. But if I'm in the city, and have my phone, there isn't really a safety issue, and there are lots of places I could walk to to get a battery. Or I could get a jump start from someone, but I can't remember the last time I got a jump start. The main purpose of the jumper cables is to start other people's cars.

I don't know what you mean by you tinder your batteries. Get them dates? Use them to start fires? You can use car batteries to run your electrical loads, but because they're starting batteries and not deep-cycle batteries, you'll be able to do that only once or twice before the batteries are worn out.

Anyway, my point wasn't that people should use their batteries until they fail. If you need to be able to start the car, because you're driving an ambulance or fire truck or something, definitely keep a battery in good condition installed. In my case, if I'm in the city, if my battery fails and I need to go somewhere in an emergency, I could likely get a ride somehow without much delay.

 

[Snap]

My 2007 OEM Subaru battery lasted 9 years with daily stereo usage with the key in the "accessory" position. I don't change my batteries until I'm unable to start the car. With that 9 year old battery it took a half second or so to start the car, and I changed the battery only because I was going on a road trip and didn't want to get stuck in the states. If I were going to stay in my home city, I would just use the battery until the car wouldn't start, and then I'd call my wife to come pick me up, we'd go to the shop and buy a battery, and she'd drop me back off at my car and I'd change the battery and go home.

Half a second, heh?
MY 2007 Forester battery turned the engine over so slow from new that you'd think it had straight 50 weight oil in 0 degree weather.
We replaced it at about 3 years out with a parts store battery with higher CCA and it turned over just the same. Probably poor starter or starter gearing design.

The 2015 doesn't turn over any faster on the 390 cca battery. They just don't seem to get some things right.
You mentioned the radio. A few weeks ago I ran the radio on accessory key for about an hour while waiting at doggie training class. Time to go, turn the key and click, click, click. Luckily one of the gals had jumper cables.

If one dome light is left on overnight the car is not starting in the morning.

Tempted to put the biggest battery I can fit under the hood.

 

[Snap]

If you need to be able to start the car, because you're driving an ambulance or fire truck or something, definitely keep a battery in good condition installed.

And if someone lives in the country where there are frigid winters? Think about being stranded in the snow in the forest; been there.
Some things are just not worth trying to save money on.

 

[kōbai-iro]

Just a couple gripes for consideration.
Looking in our manual for the battery size for replacement, I came upon a paragraph that claims the car will shut down certain lighting circuits if the battery is being discharged too much when the car is shut off. Then I wonder why I have had to recharge our 3 year old battery 3 times in a month. and how is it a car battery can't run a dome light overnight? I have flashlights that can beat that.

Yeah the 2015 manual chapter 2 page 6 Battery Drainage Prevention Function- I guess I've misunderstood that function thinking if I left a dome or map light for example switched on (with doors closed) the vehicle would automatically shut off the light(s) in 20 minutes. Not quite- if I left either a map or dome light manually switched ON with all doors closed they would remain on draining the battery. So the Drainage Prevention Function is limited to interior lights left on with any door left OPEN/AJAR. I've left a map light I manually turned on before closing doors and locking the vehicle and the light was still on in the morning. The vehicle started ok though and I had LED bulbs in all fixtures thankfully.

 

[Botnik]

And if someone lives in the country where there are frigid winters? Think about being stranded in the snow in the forest; been there.
Some things are just not worth trying to save money on.

It's not that I was trying to save money on a battery. I was just trying to reduce waste. Of course if I had had problems starting the car in the winter, I would have figured something out and that might have included replacing the battery. But I was able to start the car fine, year round.

 

[JumpingJackFlash]

I don't know what you mean by you tinder your batteries. Get them dates? Use them to start fires?

@Yoda_One said tender, not tinder. It's a good practice for some owners. Here is a link that will explain:

https://www.goldeagle.com/tips-tools/use-battery-tender-maintainer/

 

[Snap]

It's not that I was trying to save money on a battery. I was just trying to reduce waste. Of course if I had had problems starting the car in the winter, I would have figured something out and that might have included replacing the battery. But I was able to start the car fine, year round.

Good for you reducing hazardous waste.
I take them to be recycled at the scrap yard. They make it worth the trip.

 

[Snap]

@Yoda_One said tender, not tinder. It's a good practice for some owners. Here is a link that will explain:

https://www.goldeagle.com/tips-tools/use-battery-tender-maintainer/

I have a Duralast battery put in service in 2010 in a seasonal car and an AGM in a motorbike older than I can recall (perhaps 11 years), both maintained on "Battery Tender". Firm believer in that for non-daily drivers.

 

[DragonSubie7]

I guess they don't make them like they used to...
I'm still using my original OEM factory battery that is over 6 years old and still tests fine.

Or maybe I have good luck with batteries...

My motorcycle has an AGM that I keep on a Battery Tender Jr...
It is 12 years old and still has "like new" capacity. The AGM's seem to like having a full charge.

Or maybe it's the environmental change...
While batteries will lose power while extremely cold, their longevity (or lack of same) isn't because of the cold.
It's the hot summers that kill them.
When I lived in Phoenix AZ I never had a battery last 3 years in the summer heat, and that was true from anyone I knew as well.
Pep Boys would warranty and exchange mine out regularly.

 

[Yoda_One]

The spell checker got me again since I am using a new tablet. Why I tender once a month because the battery taking on a larger function. When the vehicle is stop the battery is being used instead of the alternator to save fuel. This puts a lot of drain on the battery beside all the other electrical apparatuses these vehicles need to support.

 

[Botnik]

@Yoda_One said tender, not tinder.

It said "tinder" before. I understand it now.

 

[Darkseas]

I usually replace batteries around 3 years and keep the old ones for emergencies or give them away to individuals that could use them. I also tender all my batteries once a month

I'm not sure which device you use to tender. Battery Minder makes devices that also claim to desulfate the battery plates. I've never seen any proof of that claim, but I used their product on a 2002 Ranger and 2001 Audi A4 and got about 14 years on each battery, "minding" once a month on the Ranger and when not in use for a week on the Audi. So I believe the claims.

That having been said, I think if you tender once a month, you're being very, very, very conservative changing the battery every 3 years.

As you say, however, with newer cars, the battery gets much more use, even with the car shut down completely. Some items include the security system and the remote locking system that has to constantly search for the proximity of a key. Also the cell system that constantly listens for messages to lock the doors or beep the horn and flash the lights, etc.

We forum members should jointly work on compiling a list of these current draws when the vehicle is shut down.

 

[Snap]

It said "tinder" before. I understand it now.

My wife's English friend says (and spells) "fir" all the time and shes not talking about trees. So language is an evolving thing.