A few more thoughts on the matter, some old, some new...
1) The increasing interest level, the demonstrated application to O gauge (and smaller, BTW), the DIY nature of the conversions, questions/answers re batteries/chargers/features/blah, blah, blah...all IMHO support creation of a 'Dead Rail' or Battery Powered forum category for collecting info and expertise...to help folks like this OP...and me.
2) That an OE participation in serious battery power for O gauge would help spur this forward was considered by Bachmann. Several years ago at York I challenged one of their technical reps to add this to their 150-year firsts. The story he told is that it was considered...and highly discouraged by their legal department. As is well known, application of battery power to G (Large Scale) railroads is becoming quite common, but mostly as a DIY conversion. It seems that one chap made such a homemade conversion to a Bachmann Big Hauler locomotive. There was an incompatibility, apparently, with the charger. There was a fire. There was home damage. Then, there was a lawsuit, of which Bachmann was a 'deep-pocket' defendant. Long story shortened, Bachmann was later found without fault in the matter. BUT!...the incident underscored the risks of this sort of power conversion in the hands of the common hobbyist not understanding the caveats of technologies.
And I can understand this. This sort of battery/charger mismatch problem is not uncommon with certain variants of battery and charging technologies...from my overheard experience with the R/C department at our LHS. In fact, we had one R/C customer who had proudly put together a DIY Batt-powered bicycle. Brought the whole bicycle into the store complaining about swollen batteries (LHS purchased) with a newly (online) purchased charger, plugged it all in while waiting his turn, batteries started smoking, mad dash to get him and the bicycle out the door...followed by an employee with extinguisher!
Nonetheless, safer technologies are being developed. To see the latest R/C products...drones, helicopters, boats, cars, trucks, large airplanes, gliders, military vehicles, construction equipment, etc., etc...spawned by advancing battery technologies is awesome....IMHO, of course. And, so, why not model railroading...and O scale? Fie, fie, on you, oh dirty rails! Your days are numbered!! 
3) I converted an LGB Mogul steam engine to battery power using an RCS America system...purchased at York years ago (orange hall). It still works like a charm. As was pointed out in response above, even works on carpet...NO track. Train customers that day were impressed. So am I. RCS America had O scale engines for demo at that York meet back then. Sadly, it seemed to be more of a gimmick to those who commented while I was discussing my purchase/conversion with the RCS reps.
Ah, well, like all technical change, it'll find its own destiny in its own time.
