Battery OEM BMW or OEM Subaru

with the auto start/stop eliminator installed after 1 year of ownership (using the auto start/stop feature the first 6 months and manually disabling it the last 6 months), my 2019’s battery lasted 5 years and 160k km before it started feeling weak and was replaced as a precaution.

My 2021 with 84k miles was very similar. Even had the auto start fail to restart the car once when it was cold. I just had the battery replaced with the new larger size one and it made a huge difference.

Replaced original battery at 93,000 miles. I live in Detroit. Cold winters. I guess I got lucky.

My stock OEM battery that came with my 2018 Outback lasted longer than I thought it would.

Very unlikely to be the starter, though anything is possible. I'd put money on the battery being weak though. Voltage isn't the end all be all, you need to know about the cranking amps.

Battery didn't outright die but it was weaker starting and with winter coming I didn't want to trust it.

My new BMW X3 was reliable.

It reliably would NOT start whenever the temperature dropped below -20C, even with a battery tender on it. The dealer couldn’t find anything wrong with it.

First battery lasted about a year and a half.

The only issue I had with any of them were the shitty batteries in the first two.

My 2018 has had zero problems except for a recall for battery.