I've been using a schumacher automatic with desulfator for years with no issues. Battery always out of car and cord plugged into gfci and isolated far away from flammables and battery sitting on concrete in open spot. Batteries are roatated as they peak out and sometimes charger is unpludded when everything is topped off. I check with load tester once a month or so and top off when under 12.v static and 10v under load.
Battery tenders are not regularly used and relegated to small out buildings housing tractors and lawn equipment.
Rechargable tools, name brand and only plugged in using the NON rapid charge charger only when I am home.
Fire alarms in all sructures repote buildings mounted near eave vents.
Most important. Anytime I'm away they are all unplugged.