I removed the top strap from an Aomway head strap to place the standard 1800mah Fatshark pack behind my head. It’s more comfortable than having the battery on the side of my head and the weight in the rear acts as a bit of a counterbalance to make the goggles feel lighter. I’ve also modified the cable by adding a 90-degree barrel connector and removing the other barrel connector and adding a 3-pin JST-SH balance connector with the middle pin removed. Overall it works great, doesn’t void your Fatshark warranty, and is no more ghetto than some other common solutions like pocketing the battery which I previously did to keep the weight and bulk off of my head.