Hi all
So I purchased my set of Void's second hand from a mate, practically brand new, and also experienced a noticeable drop in battery life after 8 or so months. I consider myself as pretty handy so opened the right side ear cup (7 screws first then an additional 3) to reveal the battery. The battery is taped to the back of a plastic "vent cover". This cover was perforated to obviously allow for cooling.
The battery is roughly 40mm x 40mm in dimension and about 3 - 6mm thick. It's a 1000mAh 3.7V, 3,7Wh battery. It has 3 wires coming out of it RED, BLACK & WHITE with a small white 3 prong connector on the end.
I then contacted a known battery supplier and they were able to source the battery for me. Usually batteries have a red and black cable, for the positive and negative terminals, however, the white one is connected to a very small, electronic PC board. The battery supplier said that they can fit the PC board for me if I take it in. It cost me roughly R200 (ZAR) which equates to about $15USD.
It took me roughly 5min to strip the battery from the headset and another 5min to get pricing on the battery and I am guessing it will take another 60min out of my day to fetch the battery. All in all I feel this is worth the effort. It certainly beats forking out money for a brand new set.
Here is a pic of the battery however, the part number on this battery is not the same as the one from the Void. I will edit my post with the correct code and a picture of the actual battery when I have it.
EDIT: Here are some pics of another user on Reddit that opened his as well. This is the correct battery code and specs.
https://imgur.com/a/dx1Wa
Hope this has helped some people.
Have a great day.