Purchase a battery strap that either matches your new strap, made from the same material as your strap or pick a different design altogether!. 

You can use this battery strap on the goggle strap or can use it to keep your battery/cords together while in your pocket.

All straps that come with a free BLACK ONLY one are for these goggles:
DJI v1/v2
DJI Avata
Fatshark HD Dominator / Walksnail
HDzero