I have seen those top-band oleds and some buyers got them thinking they were settable but were upset to find the 2 colors are fixed. if you can structure your UI to that, it might be ok. I do like amber on black (like old vt220's) and I run my xterms that way, too
I'll look into that fuel gauge chip. that's new stuff to me, but if its i2c, that's ideal. I will look into removing power from the display - but - isn't there some init that has to happen (at the app or library side) if the display is off? that's time overhead if the screen has to come on and something has to be written to it, yes?
I'm currently erasing the screen after a timeout and its a funny effect, since I have the screen 180 mounted (leads are at the bottom) and the u8glib lets me do that 'rotate' once and all output is all in that mode, after that. I turned that on, but the screen clearing and painting now comes from the bottom up
its kind of funny since we're mostly used to seeing draws happen from top-down. the erase if semi-fast and the draw is just barely acceptable (when there are bitmaps on the screen). the i2c 'simple' displays are actually not very fast. I will try the spi version and if I can afford the pins, maybe convert over to it.
re: battery gauge; I wonder if its even worth the screen space, cpu time and chip space, given how this thing is designed to be used. its not like a phone that will be out with you and needs to have a good 'away' run time. a remote control for a home audio/video system would rarely leave the home and would be used in very short bursts or short durations. when not being used, it sits on the charging pad, so its almost never going to even get close to wearing down the battery in real use. IF you use a charging pad or cradle, and I'm trying to see if that's a real workable solution.