Yes the EN-EL15C can work with both the D600 and D850. However, the D850 will benefit much more from the added capacity of this battery than the D600.

it will also work on MB-D10

Officially Nikon says NO. - see the email I included below. I am still waiting on backorder so I can't say for certain myself. I own a D610 and a D850. I plan to use the "C's" in my 850 and have plenty of B's for the 610 but will try both in the 610 when I have the chance. I don't see why they wouldn't work just fine. From: Nikon Support [email protected] Sent: Wednesday, September 16, 2020 1:39 PM To: XXX Subject: Your question was answered. Reference #: 05145665 [ref:_00D24ciWC._5003W4CeNo:ref] Your question was answered. Hello XXX, Your support question has been answered by one of our team members. Question details: EN EL15C ? Created: 09/15/2020 by Email | Reference #: 05145665 Response from Dave B. Hello Mr. XXXX, As the EN-EL15c has not been tested or approved for use with other products, please use the EN-EL15b. for your D610 and D7200. Kind regards, Dave Responded: 09/16/2020 by Email Reply

yes

The Nikon EN-EL15c Rechargeable Lithium-Ion Battery can last at the most approximately 120 minutes shooting 4K video. Other settings do affect the longevity of the battery.

The printing on my EN-EL-15C batteries says: "Cell made in Japan, further processed in China."

This battery is compatible with both of those cameras but you not get the full benefits of the EN-EL15c unless it's used in the newer mirrorless cameras like the Nikon z6 II or the z7 II.

No ( you cant use the camera while charging the battery )