Battery OEM Honda or OEM Subaru

It had a Honda battery in my Subaru for years

Honda batteries (at least the normal-sized ones, not so much the little 151R's) are honestly pretty solid.

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

So we bought a new 550CCA battery and installed it and it started right up. When I pulled the 18 month old OEM battery out, I was shocked at the CCA rating: 356. 356!!!! That's insane.

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.

I have a 2019 Subaru outback. The battery dies every two months and I am left stranded.

The OEM battery sucks I upgraded mine to an AGM with an extra 100 or so CCA. A better battery will also let your auto start stop last longer. Stock battery would never last a stop light for while under load new battery gives me a lot more time even under load.

My battery keeps dying if I dont use my car for 1-2 days and Subaru is failing to address the issues.

Subaru has had a problem with their electrical systems since 2014. Batteries last 2 years, max. 2018 legacy is on its third battery in 4 years. 13,000 miles. $600.00 in batteries.

Subaru batteries aren't great in the cold either