The wiring diagrams for the 6-18045 Commodore Vanderbilt can be found here:
https://www.lionelsupport.com/...8045-001Complete.pdf
https://www.lionelsupport.com/...8045-T01Complete.pdf
I have no idea what's involved with the BCR charging circuit for a Lionel model, nor do I fully understand the benefit that one hopes to achieve by installing one in a Lionel locomotive.
TRW