Abstract: Test system (10) for simultaneous testing of several batteries, in particular high-voltage batteries, comprising: a DC voltage intermediate circuit (22), several basic converters (1a-1h) connected to the DC voltage intermediate circuit (22), each of which is switchably connected to a test channel (4a-4h) via a connection line (24a-24h), a boost converter (2a, 2b) connected to the DC voltage intermediate circuit (22) which, during operation of the test system (10), is switchable to different connection lines (24a-24h) to at least one of the test channels (4a-4h) via a boost line (26a, 26b) and one connection node (18a-18h), a control unit (27) for controlling the basic converters (1a-1h) and the boost converter (2a, 2b) according to a desired power transfer; wherein each connection line (24a-24h) comprises a safety-related switch (6a-6h) between test channel (4a-4h) and connection node (18a-18h).