Something electrical is draining my battery causing slow starts

Update: I got a call this morning from the dealer’s service dept and they said my vehicle fired up fine this morning after sitting out all night. All they did was clean up some radio and fuse panel connections/wires (some of which had corrosion present) and the battery showed no signs of drain this morning. Is that really enough to cause battery drain? When I asked if the shifter button gave any resistance this morning they said that was fine as well, which makes sense if the connection from the brakes to the shifter release is electrical and the battery finally has enough juice for that to fire correctly. They suggested I drive it around for a few days and see if the problem comes back and in the meantime they’ll keep the work order open. I sure hope that simple fix took care of the issue because the last thing i need right now is to be stranded somewhere :confused: