I had to charge the battery in my car today. It sat, under cover, for 3 months. Battery dead on the car equals pulling the F150 up to it, running the jumper cables, waiting a free minutes and...vrooommm. Also noticed I was low on that evil gas.
I have several vehicles in varying states of restoration. For the ones inside my garage I have those trickle chargers that keep the battery charged but not over-charged. For the outside ones (that have batteries in them) I picked up solar chargers from Harbor Freight. They’re not great in the winter months but will keep the battery from going completely dead.