Hello all. This is an upgrade of my previous install. I installed keep-alives in two RailPro locos, the difference in performance is startling. Like having the convenience of a battery without the inconvenience of a battery. I used TCS KA4s, which are about the size of a sugar cube and wire directly into the RailPro module without a bridge rectifier. Here's a photo of the Atlas GP7 install, I located the KA4 with double-side tape on a styrene strip under the cab.I had to bend brass wire conductors for the headlight around the keep-alive as it was the easiest way to correctly position the LED behind the headlight lens. Amazing how the loco crawls through my unpowered Atlas C100 and 83 frogs, and -- bonus! -- because RailPro modules "talk" to each other the non-KA locos run better in MU configuration!