This is an interesting discussion as I’m about to strap four 280Ahr cells together. The aluminum terminals are a challenge since I don’t know the specific alloy. My anodic index cheat sheet says:
Metal / Anodic Index (V)
Galvanized Steel 1.20
Aluminum - other alloys .90 - .95
Aluminum - 2000 series .75
Tin, Tin-lead solder. .65
316 Stainless .60
18-8 Stainless .50
Bare Copper .35
Bare Silver .15
Now the rule of thumb for moderate environments says to keep the differences below ~0.25V, so:
Common, galvanized steel nuts/bolts/washers pair with the structural aluminum alloys, but not the 2000 series. Stainless fasteners pair with 2000 series aluminum, but not the structural alloys. As for copper, it had better be tin or solder plated.
I guess it’s time to find out what alloy those terminals are made of...
Metal / Anodic Index (V)
Galvanized Steel 1.20
Aluminum - other alloys .90 - .95
Aluminum - 2000 series .75
Tin, Tin-lead solder. .65
316 Stainless .60
18-8 Stainless .50
Bare Copper .35
Bare Silver .15
Now the rule of thumb for moderate environments says to keep the differences below ~0.25V, so:
Common, galvanized steel nuts/bolts/washers pair with the structural aluminum alloys, but not the 2000 series. Stainless fasteners pair with 2000 series aluminum, but not the structural alloys. As for copper, it had better be tin or solder plated.
I guess it’s time to find out what alloy those terminals are made of...