I'm starting to sound like a broken record on HN about this, but this kind of comment trivializes actual, no-kidding rape by comparing it to a low battery, and comes across as inherently misogynistic even if you didn't intend it that way.
If we really want to be serious about opening up tech and getting more women involved, and more importantly if we want a world with less rape in it, we've got to cut this kind of thing out.
Also, men can get raped too. I don't just mean women raping men; men rape men too. (Would a "Don't drop the soap" joke be too inappropriate here?) It could be argued that assuming only women can be raped is the misogynistic position.
Last, saying that we've got to cut this out "if we want a world with less rape in it" is, frankly, ridiculous. Nobody is going to read the "battery rape" comment and subsequently be more likely to rape someone.
"Rape" originally meant and still means "plunder":
> Origin: 1250–1300; (v.) Middle English rapen < Anglo-French raper < Latin rapere to seize, carry off by force, plunder;
http://dictionary.reference.com/browse/rape
Using it in this context is perhaps strong but definitely appropriate. Also, as kdommeyer noted, "kill" is commonly used in similar contexts (to kill an engine fe).
Men get raped, too.