annapro A3 Max Battery Head Strap for Meta Quest 3/Quest 3S, 20W Fast Charging 10,800mAh Magnetic Battery, Ultimate Comfort & Extended Playtime Compatible with Quest 3S/3 Accessories, White

The Annapro A3 Max Battery Head Strap 10800mah battery and 100g lighter than BoboVR. Doesn't have a fan, but you can get face interfaces with built in fan if you need one. And it comes in black or white variants.