Gaoneng 3000mAh2S is a battery designed to power FPV goggles. The battery has a standard DC5.5 connector that you can plug right into the goggles. However, it also has a XT60 connector. This eliminates the need for an adapter when charging the battery and you can also use the battery to power the FPV goggles via a long cable. There is a test button on the battery. When you press it, the LEDs will light up to indicate the battery is charged.
Please read the Safety Guidelines for Using LiPo Batteries before use.