I received a handful of new batteries for my CVP Products CNVRTR radio control battery powered system locomotive fleet to try on the PoNY. They are LiPo 500mA Turnigy brand batteries with JST-XH balancing plugs and JST BEC power connectors. I had been searching for 300 or 400mA, but all brands and outlets seemed to be out of stock.
Up until now, I have been using 3200mA, 1200mA, 1000mA, and 800mA sizes. I have yet to run a battery down during a session, but I haven't had enough sessions to prove out what is necessary for my layout for a 2-3 hour time frame. I believe I am still at overkill, though.
The May issue of MR includes an introductory article on using battery powered locomotives. In it they say that a 240mA will run for 2-3hours. I hope to find these available at some point soon to find out for myself. These batteries go for less than $10.
I am soooooo happy I am using battery power at this point, and I don't see any speed bumps on the horizon. Now I can concentrate on the decoder settings and dialing in the locomotives for the most enjoyable experience possible for my guests.