If i place a switch between two cells, should the switch be rated for the voltage of one cell or both cells? I'm guessing just one cell (4v in this example):

 

With the switch open, what is the voltage across the contacts?

 

With the switch open, what is the voltage across the contacts?

8v, oh heck.

 

In all applications the minimum voltage rating of the switch should be at least the open condition voltage across the switch. What other purpose does the voltage rating serve???

 

If i place a switch between two cells, should the switch be rated for the voltage of one cell or both cells? I'm guessing just one cell (4v in this example):
View attachment 358486

I think you can choose a switch rated for 8–12 V DC.

 

I think you can choose a switch rated for 8–12 V DC.

Once again, elementary DC circuit analysis reveals the validity of my prior statement: " In all applications the minimum voltage rating of the switch should be at least the open condition voltage across the switch."
Why would one consider any other possibility?? A voltage always is considered as defined between two points . And that is how it would be measured.