If all you do is run trains around the layout on-board battery power is probably for you. A separate forum for it on the OGR site it definitely a good idea as a result.
Many of us however also manage routes using powered switch machines to set switches up to enable our routes, just like the prototype. Almost all of these machines being electric, they have to be wired.
Also, many of us manage movements with signals, again just like the prototype. These all require wiring to function.
Unlike @Tom Tee's 1000's of feet of wire, in the broader scheme of things I'm personally saving very little by putting batteries inside my tenders.
Now, I realize that you could use pneumatics instead of electrics for switch machines, as @sjbuff has mentioned in another thread (https://ogrforum.ogaugerr.com/...5#159801037180313815), which is a good idea outdoors, and even signals if you go with pneumatically-operated semaphores, but you're eliminating very little complexity when you do either of these.
I'll stick with track power. To many of us the phrase "Electric Trains" encompasses a bigger hobby than just the trains.
I'm saving the batteries for my R/C cars, planes and boats. This is where they truly shine.
Mike
