I have done nothing special with screen brightness. By default, screen brightness under "power options" was set at a little less than half. Not sure if this helps or not, if this might make a difference or not but in between uses when testing for my 8 hours of use, I would put the tablet in airplane mode. I did this because a couple of times I took this to work where there is no WiFi and I didn't know if it would waste energy looking for WiFi when not in use. It only takes a couple of seconds to set, so I did it. I'll try to keep track of battery usage without doing that next time to see if I think it makes a difference. Portrait mode is nice for reading emags but the near 2lb weight with folio cover gets a little tiring, so I use a pillow or something to prop it up in my lap. Not a big deal though cause I rarely get hours of free time to read.