no you can not use a battery charger. There are almost no battery charges that have a filtered output, and the vast majority are not regulated.
I assume you want to use this in the shop?
Ways to go:
Find a 12v battery like a gel cell that you can use
go downtown like to radio shack and buy a 12v power supply. You need to have some idea of the amperage draw of the accessory. Either find it on the label, or measure draw while operating with a multimeter.
You want a dc 12v (13.8v) filtered, regulated power supply. Radio shack, others, sell them to operate cb radios, etc.
Like this