Battery OEM Subaru or OEM Mercedes

3yrs in on my 22 XT ,still good

Everyone's suggesting things that might save you half a percent or so, but no one has pointed out that by driving at 80mph, you lose *around 30% more battery* than if you were doing 70mph over the same distance

For my Mercedes sprinter I had the same battery in it for 10 years. I went and bought it at the dealership. Since the last one lasted 10 years. I shouldn’t have a problem with it.

Still going strong on OEM battery after 3yrs

My 7.5 yr old Forester is still on the original battery. I did need a jump a couple weeks ago after sitting with the lights on for a half hour, which was weird, but it's been fine since

I had this issue as well, one day the car wouldn’t turn over. Then it would. Then there was no power. Then it would start. Over several days and weeks this would happen. It was explained to me that the Subaru batteries that come from the factory are made to hold just barely enough power to start the car. If that power is diminished in even the slightest degree, like with normal usage in the first 50k miles, then the battery does not have enough charge to do its basic task anymore, rendering it useless. As I understood it, the batteries in the new cars are not up to snuff.

Replacing my battery recently

A new battery at 10k miles.

Battery died around 50k miles.

My 2020 Outback OEM battery only lasted 3-ish years.