For those who need to replace the lithium battery in the xp deus coil and would like the metal detector to work longer. Some photos of procedure:
These are new batteries with larger capacity - 1000 mAh.
It's size in comparison to standard xp deus battery:
New battery inserted inside the search coil:
Cover is closed:
Also one my friend used DIY change in 9'' search coil also with battery of larger size for longer life during prospecting (60 mm x 18 mm and 9 mm thickness) and it perfectly fit to the battery slot: