Like some others, I use battery power for my coach lights. Being all battery power, naturally this is what I do. I use Christmas tree LED lights with a 1K ohm in series with each light. With a dedicated 11 or 14 volt li-ion battery, it lasts forever. This way you have to charge the battery on rare occasions, but you don’t have to worry about varying voltage, electrical contacts through the trucks etc.
Ed
When you reference BB wheelset are these what you refer to?
http://www.trainli.com/btrainlineb-prowheels-with-power-pickup-p-580.html
That is pricy per car.
I haven’t found the source for the carbon brush Pick Ups. Hint?
Trainworld still had some Aristocraft carbon pick ups for sale the last time I checked. I bought some to have in my spare parts box.
Carbon pickups, Aristo, USAT…
BB wheels, Train-LI, Aristo, AMS/AML…
Greg
p.s. guys, I really wish the battery guys would remember that the OP runs DCC, and has basically unlimited power nice and close by, the wheels will be cheaper than batteries… less space used in the cars, no recharging, etc. Let’s not turn this into a battery vs. track power thread.
Greg, the OP also said that sometimes he runs DC. So adding a capacitor to his circuit, and designing the circuit to run on a lower voltage, would be needed for running on DC then for running on DCC,
The Bachmann coaches came with battery holders. I gave up on having a 9 volt battery in each car due to the hassle and expense of having a supply of 9 volt batteries on hand. Track powered lighting has its advantages as well as its disadvantages.
Just as an FYI, I just picked up a string of LED warm white Christmas light at Wallgreens for $2.50. They are the kind with the dished in top, for more of an all around lighting. I figure that I can use those LED for lighting my cars. I just need to get some of those cl2 chips, bridge rectifiers and caps.
The “Concave” type you bought are good ones for the coaches. They have a good 120 degree angle light output.
Show us some pictures of the final installation when you can.
Dennis
With regard to the life of on-board batteries, I have some coaches that have had the same batteries in them for three years!! Some of my earlier projects just used a set of AA batteries in a battery holder with a separate toggle switch located under the car. My later lighting technique uses a 9 volt battery housed in a nice black battery box with an integral slide switch. The battery boxes comes with wire leads. I mount the box under the car. To me it looks like some mechanical equipment that belongs there. It’s simple, inexpensive and easy to accomplish.
Dan, yes, and with LEDs the batteries may last a long time. With the incandescent bulbs that Bachmann used, a 9 volt battery didn’t last all that long. But then I did do a lot of night running when I had working lights in my coaches.
Dennis, lighting my coaches with those LEDs is not in the to 20 on my to do list right now. Someday I will get to it. 
The OP started this thread because a similar thread went sideways.
I’m respecting his effort and contributing with that focus. If it starts to go sideways again, then it’s not worth the effort.
There’s a lot to be learned here, and I would like to share some knowledge I have, but if it gets to be too much effort, then the heck with it.
There’s several ways to get power from the rails, and some are surprisingly inexpensive.
Greg
Greg, yes. That’s why I want to make either wheel or axle wipers out of some free phosphor bronze I have. Free is even better then inexpensive. 
OK guys, I run the DC power pack for visiting locos’ (neighbor Kids) and until I can get a decoder install into a new loco.
The main thrust is for DCC off the track.
It’s very obviously that I need to start with the Pick up issue before it goes very far along. Bad Pick up and the rest is a waste of time.
I’ve got some homework to attend to.
So Dave, I think it comes down to the cost.
easiest to do, but most costly are the ball bearings, which would be my choice.
The carbon brushes can work, but they take maintenance and add drag.
The “eyelet” type of pickup will work well, but you need wheelsets with one wheel NOT insulated from the axle.
So what do you think?
Regards, Greg
I can’t find anyone offering up the Aristo brushes, I did find these on the USAT web site.
Are they what you mean? The Price is right. Would I need two per car or one per car?
Can they be made to fit on Bachman style trucks?
Dave,
I used the LGB brushes with my B’mann coaches. They fit well with a little coaxing. I used two per car and used 2 capacitors, 5 LEDs, a resistor and a bridge rectifier in each car. It worked really well.
Dave, I am not sure how easy they would be to mount to your trucks, but with a little work they probably could be mounted. 2 per car (1 per truck) would be better then 1 per car.
Yep, keep them clean and oil free.
Most Aristo and USAT trucks have two holes in the truck for mounting, but easy to mount.
Greg
He asked about putting them on Bachmann style trucks. The Bachmann passenger trucks I have, actually have the sockets (for lack of a better term) for the brushes to fit into. But you would need to work out the power wire part for those sockets. I have thought about using the LGB brushes in those sockets, but I haven’t tried them to see if they will fit or not.
That’s what I said above. I used the LGB brushes in my B’mann coach trucks. They fit those “sockets” with just a wee bit of reaming with a drill bit by hand. You must solder the wire on before pushing them in the sockets. Drill a hole in the car bottom, leave a little slack and do your hook ups.
Joe, my apologies. Yes you did say that. Thank you for the clarification.
Next question. Do they add a lot of drag to the cars?