Power supply system

A power supply system configured to supply electric power to a vehicle, the power supply system comprising:

• a power conversion device;
• a battery unit that is electrically connected to the power conversion device via a wiring;
• and
• a case, wherein
• the case includes:
• a first case portion that defines a first internal space for housing the power conversion device;
• a second case portion that defines a second internal space for housing the battery unit;
• and
• a partition wall portion that separates the first internal space and the second internal space from each other and has a connecting hole that connects the first internal space and the second internal space to each other,
• the wiring extends between the first internal space and the second internal space via the connecting hole,
• the first case portion has an opening portion that opens downward,
• the connecting hole is positioned above the opening portion, and
• the power supply system further comprising a lid member that is capable of opening and closing the opening portion.