If you want to learn more about battery-power and BlueRail in S gauge, Peter A. Vanvliet (NASG web site master) is very knowledgeable and experienced in that part of the hobby. Not to mention responsive, friendly, and helpful.
Peter’s site https://pmrr.org/
Peter’s battery power article https://pmrr.org/Articles/index.htm#Battery_Power
Peter’s email peter@fourthray.com
S-cab web site - a manufacturer mentioned in Peter’s battery power article. https://www.s-cab.com/
Have fun running your trains.
No matter how they're made to move.
Dave