The EcoFlow Delta 2 impressed in the test with a storage capacity of 1,024 watt hours and a constant output power of 1,800 watts. In the endurance test, it lasted an impressive 10 hours at a load of 80 watts. The battery was fully recharged after just 1 1/2 hours at the socket. However, additional connections or a surface for wireless charging of smartphones would have been missing for an even better rating.

The older Delta 2 is a cheaper alternative to the test winner. There are plenty of connections: four USB-A and two USB-C sockets. In combination with the manufacturer's inverter, it becomes a balcony solar storage unit.

Performance, runtime and charging time are good. Apart from the somewhat sparse comfort features - including covers for all connections or a lamp function - there is hardly anything to criticise about the Delta 2.

Performance, runtime and charging time are good. Apart from the somewhat sparse comfort features - including covers for all connections or a lamp function - there is hardly anything to criticise about the Delta 2.