In one of my university courses we learned about electrical safety. Things like that many amps will kill you, the difference between how high frequency AC and DC affects the human body etc. Also things like one in X thousand people is a lot more resistant to electric shock than normal people. I remember that the fact was given either in a book or my professor (can't remember cause it was more than 10 years ago) which kinda stuck with me. It was said that most of these facts are known thanks to experiments done in concentration camps. I checked in the previous posts on this subjects regarding nazi scientific experiments but couldn't find any mention of this. If that's true I wonder why I didn't see it mentioned somewhere, cause it seems significant enough.
While it's difficult to prove a negative, I've never seen electricity referenced among the Nazi experiments, and I can't find any now. While I can find reference to Nazis using electricity, it's only as a method of torture, not as an experiment.
I think you may be confusing this with the Nazi hypothermia experiments. These were considered an important source of information about how long a person can survive in different temperature waters, (useful to sailors and whatnot) but some have suggested that the studies were poorly done and that the data is useless. cf http://www.nejm.org/doi/pdf/10.1056/NEJM199005173222006
A lot of the early research (primarily animal) on the effects of electricity was carried out by Thomas Edison's labs. His nominal purpose was to show New York -- at the time, in the market for a new way of executing people that was supposedly more humane than hanging -- that electrocution was a viable method of execution. His more vital purpose from a business perspective was to associate AC with death, and thus prevent Westinghouse's AC power system -- on which he wouldn't receive any patent royalties -- didn't take off. Edison's research was done in the 1880s. Executions by electrocution were being done from 1890 in the United States.
http://www.pbs.org/tesla/ll/ll_warcur.html
Perhaps the Nazis did some experiments on electrocution, but I find it hard to believe that we'd know much less about it if they hadn't, since by the 1940s they would have been doing research on a phenomenon that had been researched -- and even had had people dying of electrocution is highly controlled, highly observable circumstances -- for 50 years.