I bought a 2019 Outback when I retired and have mostly been happy with it...a bit of a learning curve on the electronics, but all-in-all satisfied. And, a major purchase issue was I wanted to get out on the "roads less traveled" and thought the AWD would be essential. It seems to be because I have been in many places in the past year where I know I would have been stuck in a regular car. BUT, in the process of moving to a new house, hauled a bunch of hoses in the back of the Outback. Of course, got water all over back there. When I got to the "old home," parked and opened the hatch to let it dry/air-out. This morning -- dead battery. WHAT. I made sure the hatch light was switched to off, so no issue there. Just wondering why/how leaving the back hatch open for 14 hours kills the battery. Did some online poking and find it is indeed what happens when you leave the Outback hatch open. The Outback has a group 25 battery, which seems is known for being a weak POS -- pretty dismal 325CCA. I have it on the charger at the moment. I won't replace it now, lots of expenses with the new house, but hopefully next month -- no later than Nov. 1, anyway.... But, a question. Lots of posts on the Subaru forum about going to a different battery. Group 24, which apparently fits fine, or the Group 36, which requires some finagling. But, I can get a Group 25, I know fits, from NAPA with MUCH better specs than the OEM, so thinking why not stick with the 25.
if it has better cca, i would go with it. how often are you going to leave the hatch open overnight? once burned, twice shy
I don't pretend to know how to spoof a 'hatched closed' condition in a Subie, but I would DEFINITELY use a larger-than-OEM replacement - or at the very least augment with a decent jump pack. Many OEMs are trying to figure out how to shave costs (and weight) when and where they can.
This. When our 2015 Outback's battery bit the big one @ 4 years, I switched to a physically larger battery with more CCA as, yes, there's room. Sorry, I don't recall the group size. My guess on the cause would be either or both the power hatch system or SKS staying hot and not shutting down because the hatch is open.
I have a suspicion that your Prius will do the same thing, though the particular number of hours to flat battery will be different. The open door causes some other electronics to remain on and drawing significant current.