I do not use a switch and have never had a single issue. I measured the current when the Graph is off, and it is only 13 mA. That small current will not run the battery down (I use a 50 AH Lithium for my electronics), it would take months to run a properly sized battery down. If I would ever need to turn it off, I can disconnect the power lead, or pull the fuse, but I never have needed to.