Battery Deka or OEM Subaru

Yeah they use undersized batteries, but just buy a good one and that's the end of it. my 2019 Legacy had is original battery after 4 years when I traded it in.

Yes. Subaru batteries are hot garbage. Go third party all day. I stand by any AGM I can pick up at Autozone, since they stand behind the batteries they sell.

Deka ETX15, Deka makes a great battery and they’re sold under a few manufacturers.

My dealer replaced the battery, updated the firmware and did a parasitic drain test.

I use Deka for all of my cars and they take Minnesota winters like a champ

Deka is the best I’ve found.

Any tips or advice before I fork out money for a new battery? I have some anxiety hoping its not the alternator dying, or less likely the starter. All things point to a slowly dying battery but I want a second opinion.

It's a known issue that Subaru batteries fail much too early. Subaru began warranting great numbers of them a few years ago.... And they kept using "The same faulty batteries"!!! ...and they still are.

Could be worse ... I bought a new 24 OB and within 3 months, the battery was replaced. Love the car, but crap batteries

I had this happen in my 2020 outback around 37k miles. Dead battery was the culprit. Fortunately I shut off all my electronics and lights and it had just enough power to get it to restart. I got the battery replaced by Subaru under the extended 5 year warranty from a settlement for premature battery failure. It failed right after my 36k service at the dealer I think the car was about 4 years old at the time.