Karma Won't Power On - Stuck Inside

Hello. I have a 2018 Karma Revero and I took it into detail car wash last week and as they were moving it from the wash section to the dry section it wouldn't power on. The employee was inside the car and it wouldn't power on nor would the windows or doors open. Nothing would work. They called me over to help and the FOB wouldn't work, the extra FOB I had at work wouldn't work, opening the doors wouldn't work, the poor guy was in there for an hour before I had to take an Uber home and get the manual key to get him out. It turned out the 12v battery failed and needed a new one but it made me think that what if it happened again and I'm in the car on a hot day and I can't get out and nobody can get me out because they don't have the manual key. Sure I can break the window or call AAA but seems like a huge issue and worries me to the point of maybe I should get another car. Anybody else have this happen to them?