My 1991 Honda motorcycle does this too. I can promise you that it has no smart features. It doesn’t even have a fuel pump. Lead acid batteries just don’t have long shelf lives.
I'd like to think that at some point the parasitic drain devices will shut down before they drain the battery completely, but I've never tested it beyond that point, I always plug in the charger if the car's going to be parked for more than a couple weeks. I installed a charger plug that comes out the front grill so I can plug it into the battery maintainer without even opening the hood.
To this day, since ~1980, I disconnect the +ve battery lead if the cars not going to be used for a few days or parked up in the bush waiting for when we get back from a walk.
Stops parasitic drains and Heisenbug discharges when thermal expansion during a very hot day causes a hard to track short.