Can i create a 12V battery from two 6V batteries? if so, is the process safe?

i need a 12V DC source for electrolysis but i dont have a 12V battery. i heard i could make a 12V "battery" by connecting two 6V batteries in series. i know how (just connect the negative terminal of one with the positive terminal of the other using alligator clips) but is anything about this process unsafe? it won't explode or anything, right?