I am having the same, or a similar issue. Over night the battery is going dead, did it the last two nights in a row. As soon as I hook it up to my trickle charger the car will start and runs okay. The 12 volt battery was last replaced in Dec of 19 so I doubt that it is bad already. I bought the car used in March of '17 (it's a 2013 hybrid) from a dealer so I would think (or hope) that the software upgrades were completed before I bought it. Any suggestions as to how the 12 volt battery is being drained?
Thanks,
Pete