A spare battery for the Ewave electric surfboard with a capacity of 2.5 kW and weighing 10 kg. It has a voltage of 48 volts and a capacity of 56 Ah. It is inserted in one movement into special grooves. The duration of riding on one charge is 30 minutes, while it will take about 2 hours to fully recharge the battery. The battery case is made of metal. Convenience of operation and transportation is ensured by two ergonomic handles located on the top panel.