I used OO for various thingsover the years, including box-diagrams kinda like battery layouts but not for that purpose; but not since before the housefire, and even that was an old version, and I used Visio at least a couple decades before that, I'd guess it was, for flowcharting, at work, but I'm sure both have changed since then.
Both were about as intuitive as I'd expect, and the paradigms they used for control of objects and layering were about the same as most programs I've used that do those things, so they should be pretty intuitive either way.
OO has the advantage of being free, so you can try it out and see what it does for you, and if you don't like it then you could see if Visio has a "test drive" version.
I've not tried anything else in the second link; I just found it in a google search for the current website of OO, and thought it might be helpful.
I have also used Paint that comes in Windows to do similar stuff, but it is a PITA because you have to use multiple instances and paste between them in the right order, as there are no layers in it. Back when PaintShopPro was shareware, I used it for that, too (v4? 5?) because it did have layers and such, but I havent' found my installers for that since a hardware problem years back that left my backups on DAT inaccessible.
(I have replacement drives since then, from junked computers, but haven't tried to see if the installer is still on any of the tapes).
If you think you're going to make PCBs for the circuits, and not just wiring diagrams, I'd go with one of the PCB designer programs that've been recommended around the forums over the years. Cant' remember any names ATM, but will post a link to threads if I find some (gotta go feed and give meds to Tiny and Yogi right now, though).
