This document discusses different electrical power generation and storage systems used in train coaches. It describes four main systems: 1) Axle Driven System which uses alternators driven by axles to charge batteries. 2) Mid On Generation System which uses a power car with a diesel generator set placed mid-train. 3) End Of Generation System which uses power cars with large diesel generators at either end of long distance trains. It also discusses the alternators and batteries commonly used in different types of coaches, and provides details on the charging process for lead-acid batteries.