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Here's how a Nikon D80 camera battery indicator can look like (depending on charge state)

battery states

You see, it's a usually looking "battery cylinder" symbol, but the "cylinder" perimeter is open - the lower line has a gap. To me it looks weird because I got used to such symbols with the "cylinder" having closed perimeter. This one looks "leaking".

Does that have any standard meaning? Why use this instead of closed perimeter symbol?

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up vote 11 down vote accepted

I assume that you noticed this gap only in simple one-color LCD displays, like we have in digital watches. In such displays, there are no pixels, but areas that are predefined on the screen that can be lit on or off. A technical restrain is that each area has a "clear" path to the edges of the screen, so it can be supplied with invisible electric contacts. See in the example below how the display is made out of independent areas, never touching each other.

enter image description here

In the example of the battery meter, the "blocks" within the batter need an opening to let the electric contacts reach them. This is why I believe your observation of the gap is not an intentional feature, but an arbitrary artifact. I guess that if the engineers had a choice, they would draw the cylinder of the battery closed.

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If it was such an artifact, wouldn't the top line also have a break in it? – 17 of 26 Jul 31 '13 at 13:40
@17of26: No, because that line makes use of the gap from the bottom line. It's possible that a variant on this question would be on topic within electronics.SE, if you want an answer from that perspective. – Brian Jul 31 '13 at 14:13
Some LCD battery displays do have gaps top and bottom, probably for aesthetic reasons. – Dan Hulme Jul 31 '13 at 18:08

Notice that the gap is at the midpoint of the battery, giving you a visual indication of where the 50% charge point is. That's my guess.

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I think you could tell where 50% is from the middle bar, since there's 5, it's not difficult to figure out... I don't think it has anything to do with the midpoint. – Mike Jul 31 '13 at 14:32
The accepted answer looks correct (though the battery might better show top and bottom gaps in that case), but this answer mentions a truth about the UX, so I don't think it deserves to have a negative score. By the way, the first thing that came to mind for me was that the gap made the battery look like the top half of an hourglass, to reinforce the concept of the battery draining (even if it does look too much like leaking, as the questioner mentioned). I don't think I will be posting that as an answer, though, if downvotes come as easily as they did earlier for this answer. :S – A.M. Aug 5 '13 at 18:23

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