System for replenishing an on-board power source for a propulsion system on a vehicle such as a watercraft and process

A system and a process for replenishing an on-board power source for a propulsion system on a vehicle such as a watercraft are disclosed herein. The power source comprises a first reservoir holding an anolyte and a second reservoir holding a catholyte. The system comprises a shoreside source of DC electricity; a shoreside series of one or more interconnected stacks; and a hydraulic circuit for circulating the anolyte and catholyte. In embodiments wherein two or more shoreside interconnected stacks are used, the stacks may be hydraulically connected in series or in parallel, and electrically connected in a parallel arrangement.