[pgrey]

Yeah, I've been using AGMs for >25 years now, and IME (I'm sure there are some bad batches, just like ANYTHING out there, pretty much), they're pretty bomber.
If you charge them every so often, they last 5-6 years, easily; I don't think I've had a single Optima that's failed prior to 5. They're pricey (sort of, gap seems to be getting smaller these days), but there's something to be said for appliance-like reliability, and not having to think too much about it...

 

[SilverOnyx]

Optimas are reportedly not as good as they used to be so I no longer recommend them - used them back in the day though. Also used Odyssey batteries which are supposed to be still good.

 

[flixden]

Somehow, my inexpensive regular batteries have lasted 7+ years in most cars and our travel trailer, the Subaru being really the only exception. Maybe I was lucky.

 

[SilverOnyx]

Somehow, my inexpensive regular batteries have lasted 7+ years in most cars and our travel trailer, the Subaru being really the only exception. Maybe I was lucky.

I'm pretty sure that the "smart" charging algorithm is bad for batteries - your 2016 had the TSB right? I also suspect that battery quality has declined (battery manufacturers being bought by private equity) at the same time that electrical demands are increasing in cars - a perfect storm.

 

[SilverOnyx]

So I took my car to the dealership for a separate issue, but mentioned to them that my battery seems weak and that it registers low resting voltage like 12.2 when I expect it to be closer to 12.5 and I asked for a load test. So they claim my battery was at 12.68 volts and measured at 904CCA. I drive the car home and get 12.33 with my voltmeter.

 

[pgrey]

Optimas are reportedly not as good as they used to be so I no longer recommend them - used them back in the day though. Also used Odyssey batteries which are supposed to be still good.

Yeah, I've heard anecdotal talk of the same, but not much empirical evidence?
I think the industry has declined as a whole, becoming a largely commodity-index type of deal (instead of more evolving-engineering-based), but this seems to apply to almost all the brands.
Maybe Odyssey is better these days (they seem to have leveled a bit, in terms of price), but they also get anecdotally bad reviews, here/there?

 

[ArF193]

So what's a good and reasonably priced replacement, considering somehow my S/S system never activates?
I want to be ready, I don't think the battery Subaru installed in our Gen6 will last very long.

There is an H5 AGM battery that is available, in two versions, at Walmart/Sams and sometimes at select Costco stores. Walmart has a version for about $115 and another for about $155; they will install the battery. Costco requires the customer to install but are very liberal for returns. If you desire extra capacity I think the H6 will fit in the space but the battery blanket will need to be left-off. I have increased the battery size for my replacements and they have never failed me or left me stranded. Of course this ASS thing may be a different experience.

My LN2 battery is being charged at 14.1V almost all the time. If I turn the ASS off then after a long drive my battery is at 12.5/6V when I park. In less than 24 hours it is setting at 11.9V. I expect it to die so afraid to go on a long road trip without jumpers plus a charger and extension cord.

 

[ArF193]

Yeah, I've heard anecdotal talk of the same, but not much empirical evidence?
I think the industry has declined as a whole, becoming a largely commodity-index type of deal (instead of more evolving-engineering-based), but this seems to apply to almost all the brands.
Maybe Odyssey is better these days (they seem to have leveled a bit, in terms of price), but they also get anecdotally bad reviews, here/there?

Costco Kirtland Batteries lasted a long time if properly maintained. My last Kirtland was 7 year old when it went with a car I sold. I took it to Walmart for testing to verify it was good before selling. My other vehicle had the interstate that was less than 3 years old and it failed the test at Walmart. The guy at the tire counter at Costco said they were seeing lots of returns since changing suppliers.

So I took my car to the dealership for a separate issue, but mentioned to them that my battery seems weak and that it registers low resting voltage like 12.2 when I expect it to be closer to 12.5 and I asked for a load test. So they claim my battery was at 12.68 volts and measured at 904CCA. I drive the car home and get 12.33 with my voltmeter.

View attachment 498614

It would have been interesting to compare the Dealer Mode voltage to the two sources you gave.

 

[SilverOnyx]

Obviously the dealer charged the battery just before "testing" it and the 904 CCA tells me their methodology was flawed - it's not possible (someone correct me if I'm wrong). It would be like if they told me the battery was at 18 volts.

 

[ArF193]

My Honda came with an AGM battery but I'm still learning about it.


Based on some research, I know that I must use an AGM charger & maintainer.

Battery Tender (maintainer at 2A max) state on the package, going back almost a decade, they work for AGM charging.

 

[flixden]

Obviously the dealer charged the battery just before "testing" it and the 904 CCA tells me their methodology was flawed - it's not possible (someone correct me if I'm wrong). It would be like if they told me the battery was at 18 volts.

They probably disconnected a charger and then measured right after? Batteries will read high for some time.
I agree that the results are suspicious.

 

[JB D]

Yeah, I've been using AGMs for >25 years now, and IME (I'm sure there are some bad batches, just like ANYTHING out there, pretty much), they're pretty bomber.
If you charge them every so often, they last 5-6 years, easily; I don't think I've had a single Optima that's failed prior to 5. They're pricey (sort of, gap seems to be getting smaller these days), but there's something to be said for appliance-like reliability, and not having to think too much about it...

I have a 2019 Outback 2.5L and the OEM battery has blown a fuel cell. We moved from California to North Carolina needles to say a colder climate. I’ve been searching for an AGM battery but they don’t have one that fits the 2019. I thought since you know a little bit about the AGM would you think the AGM 35 or the 24 would work?

 

[SilverOnyx]

Don't know if you've seen this thread but it might be good reading: Gen5: Replacing the original battery with BETTER

Seems people like the group 24. Try to find the Odyssey one if you want the absolute best.

 

[JB D]

Don't know if you've seen this thread but it might be good reading: Gen5: Replacing the original battery with BETTER

Seems people like the group 24. Try to find the Odyssey one if you want the absolute best.

Thanks !

 

[ArF193]

I remain concerned that my LN2 Battery may have premature failure. It continues to show <11.9V in Factory Mode after setting for 12 hours. If this battery is not replaced during the three year warranty then my plans are to replace it with an AGM Battery yet to be defined. I will list some of my random thoughts and summary about this topic.

1. The Battery Tender Plus, purchased 12/01/2012, says it will correctly recharge AGM, or any type lead-acid, batteries as confirmed by the included photograph of the package located below.
2. In November of 2019 I was able to find H5 Batteries with CCA of up to 650. Today, they are no longer listed at 650CCA for the same brand sites or on the shelves.
3. I am currently having difficulty finding H5 Batteries at Costco, Sam's, and Walmart. However, the H6 750CCA Batteries seem to be more available.
4. Different battery dimension charts may vary in their dimensions listed for the H5 & H6 Batteries so the replacement fit remains a big unknown. The current LN2 is rapped in a sleeve which could be unnecessary in some climates. I would like to install a 750CCA H6 Battery but not sure about the actual size of each option. Best case I found was a difference in length of 1.5". Also, the current battery tray length is approximately 10.1" and the smallest H6 length is listed at 11". The trays in my Toyotas were flexible and therefore allowed for battery overhang but not sure the same is true for the Subaru Tray. I would also need to obtain the center-line dimension for the battery posts because of concerns for connecting cables length being too short.

During the next 1.5 years I will continue to search for information about the installation, or attempted installation, of an H6, Group 48, Battery in a Gen 6 Outback. If that does not happen, then I will likely go to Costco to purchase a H6 Battery with the understanding I will be able to return it if I can't make it fit. I will also look at purchasing a battery tray from Toyota.

 

[SilverOnyx]

Group 47/H5/L2 Odyssey AGM battery is available through NAPA, or direct - Autozone also sells their batteries but doesn't list that size yet. Not sure if it can be special ordered.

ODP-AGM47 H5 L2

Looking for an ODP-AGM47 H5 L2 (47-650) ODYSSEY Performance Series battery? Buy it online at OdysseyBattery.com - the official manfacturer's website. Whether it's a battery for your car, boat, RV, a powersports battery or a heavy duty / commercial application battery - powerful performance...

www.odysseybattery.com

https://www.napaonline.com/en/p/ODBODPAGM47H5L2

@blaydesglobal has one GEN 6 Battery POWERTHREAD

@evgzyx has one GEN 6 Battery POWERTHREAD

I'm trying to get one myself but the local NAPA says they can't get them yet.

 

[ArF193]

Group 47/H5/L2 Odyssey AGM battery is available through NAPA, or direct - Autozone also sells their batteries but doesn't list that size yet. Not sure if it can be special ordered.

ODP-AGM47 H5 L2

Looking for an ODP-AGM47 H5 L2 (47-650) ODYSSEY Performance Series battery? Buy it online at OdysseyBattery.com - the official manfacturer's website. Whether it's a battery for your car, boat, RV, a powersports battery or a heavy duty / commercial application battery - powerful performance...

www.odysseybattery.com

https://www.napaonline.com/en/p/ODBODPAGM47H5L2

@blaydesglobal has one GEN 6 Battery POWERTHREAD

@evgzyx has one GEN 6 Battery POWERTHREAD

I'm trying to get one myself but the local NAPA says they can't get them yet.

Thanks I will need backups for my plan which is likely not to go as "planned."
I am thinking Costco because of their return policy, which is difficult to beat for the average consumer.

 

[robb12088]

I thought since you know a little bit about the AGM would you think the AGM 35 or the 24 would work?

Best Battery for Subaru Outback - found this via Google... not sure how accurate/reputable the site is, but there's a section halfway down the page "Subaru Outback Battery Specifications". Even though the article was posted March 2020, it never references what model year of Outback the information is applies to, so I can't verify the info. However, after reading through this forum, seems like the official size for the Outback battery is Group 24, while the Group 34 and 35 are close enough in dimensions to fit the space.

Please don't quote me (or site I refenced) as "gospel"... I'm just like most folks here trying to figure out what type of aftermarket AGM battery to look for!

 

[robb12088]

Best Battery for Subaru Outback - found this via Google... not sure how accurate/reputable the site is, but there's a section halfway down the page "Subaru Outback Battery Specifications". Even though the article was posted March 2020, it never references what model year of Outback the information is applies to, so I can't verify the info. However, after reading through this forum, seems like the official size for the Outback battery is Group 24, while the Group 34 and 35 are close enough in dimensions to fit the space.

Please don't quote me (or site I refenced) as "gospel"... I'm just like most folks here trying to figure out what type of aftermarket AGM battery to look for!

this site seems a bit more legit for battery information - BCI Battery Group Size Chart

 

[SilverOnyx]

However, after reading through this forum, seems like the official size for the Outback battery is Group 24, while the Group 34 and 35 are close enough in dimensions to fit the space.

What you're saying applies to the 2015-2019 5th generation Outback, but not to the 2020-2021 6th generation Outbacks.

The 2020-2021 Outback battery size is definitely Group 47 H5 L2/LN2 as evidenced by looking at the battery, measuring it, and people having put perfectly fitting Group 47 batteries in their vehicles, so there's no confusion about that.

Whether or not a larger size battery can be shoehorned in is not well explored.