On "older" Nikons like the D50, D90... that have the DC IN port, when an EH-5a AC Adapter is connected, does it JUST power the camera, or does it also charge the battery? I haven't been able to find a good, solid answer online.
According to Nikon USA, it is just a power supply and does not charge the battery.
Q: Will this also charge the camera batteries or is it just a power supply?
A: It's just a power supply.
See Q&A at the bottom of this page.