There's a charger for the D2h, a different one for D700, another for D800 and yes, another for D4. My D4 battery sure looks like the D2h battery...except for a different number. Of course, I won't try recharging one in the other.
What if Nikon had the same battery for all of them. 😀
"Today is the tomorrow that yesterday you spent money like there was no."