There seems to be huge difference between how the Venu 2 and the VM Sport calculates body battery. See the graph - I slept with the VM Sport and switched to the Venu 2 before I went on a run (no intervals on the Sport).
I've checked at the max puls is the same (it changes for all watches, when I change it on one watch). Any idea on what else to check for?
(personally I think the VM sport is close to the truth - I do feel fully recharged, and the Venu 2 often have me at 70-80% even after a really good nights sleep)