I noticed that in dry voltaic cells the "cathode" has a surplus of electrons and the "anode" has a surplus of positive charge. Electrons flow from the cathode to the anode to produce an electrical current.

 

However, in hydrogen fuel cells the "anode" has a surplus of electrons and the "cathode" has a surplus of positive charge. Electrons flow from the anode to the cathode to produce electrical current. This is opposite from a dry voltaic cell.

 

What's the convention for determining the anode and cathode? There's a lot of conflicting info on the internet. Thanks.

It can be found by examining whether the electric cell in question is a galvanic cell or electrolytic cell, for starters.

It can be found by examining whether the electric cell in question is a galvanic cell or electrolytic cell, for starters.

 

The cells that I'm studying are galvanic (voltaic). Specifically, zinc/copper galvanic cell with a sulfuric acid electrolyte. Any ideas?

For galvanic cells, the anode is negative and the cathode is positive. For electrolytic, the reverse is true.