I took My xp deus 1 for a hunt this morning the first couple of hours it was fine but after 3 or 4 it started chattering would it be the battery going down or the temperature rising
Nokta FoRs Gold, a Gold Cube, 2 Keene Sluices and Lord only knows how many pans....not to mention a load of other gear my wife still doesn't know about!
I've never used a Deus, but, that chattering could be from a number of sources. It's possible you were working some highly mineralized ground with the sensitivity too high, or it could have also been EMI coming from some local source.
Do you have a coil cover? Be sure to check underneath it to be sure there's nothing metal or foil causing the issue.