NHTSA Complaint #11503566 — 2019 SUBARU OUTBACK

Ever since this car was new it has always dragged while starting. Like the battery was weak but, its my first subaru so figured it was the style of starter. After a couple years the battery got weaker and weaker until it died. Replaced battery and it started doing the same thing. Now, the car is 4 years old and this is our 3rd battery. The alternator charges 14.6 volts which is perfect. But, sitting overnight the battery is constantly being drained. If i put a charge on it and remove it from car it holds the charge. So, it isn't the batteries plus, we had the battery and alternator tested and those aren't the problem. The vehicle constantly drains the battery while sitting overnight. After a few days it won't start at all. Subaru says there isn't a problem. I have a sickly parent living here and he has to go to the hospital regularly and we need that vehicle to work properly. Is there anything we can do about this.