2017 subaru forester (basic,no frills) battery drain

The vehicle was purchased in Oct., 2016, it now has 850 miles on it. I drive it daily but not many miles. In July I purchased a new 7 year battery for it and again, have treouble starting it 4 wks. later. I'm 84 and have no desire to start using a trickle charger on a brand new car. Any workarounds? Anything that I can permanently disconnect? Any thoughts? I'm not going to go out and drive around the countryside to accomodate this thing. Thanks for any help you can give me.

A car this new should still be under warranty. You need to have a parasitic loss test performed to diagnose what is killing the battery.

stealthee- Thank you for your help.