battery power g scale

I would like to build a g scale garden railroad but do not want to depend on track power. What is the simplest/cheapest way to get a locomotive that will run on battery power?

Don’t know a cheap way. I use radio control/battery power on my garden railroad. I use RCS, distributed by a guy in Oregon who advertises in GArden Railroading. LocoLinc is another company.

Though I am not in to the G scale thing myself, what some of my friends have done is to use a 14v cordless drill battery connected to an aristocraft remote control in a boxcar behind the loco.