On Android, I've found that Google Now, location history and network location waste a ton of battery.
If you don't use Google now, disable it, disable location history and set your GPS to device only or else Play Services will wake your phone to ping your location and scan wifi access points a ridiculous amount of times. For the geeks you can Google NlpWakeLock to see what I'm talking about.
Aside from that, set your screen brightness to as low as you can handle and avoid Chrome if you can. Something like Opera Mini is fine to browse most static pages and is incredibly light on battery, with the caveat that complex pages may not function.
Whenever I noticed unusual discharge, the first thing I check is what apps are using what % of battery. Usually it's pretty obvious. I've used Betterbatterystats to track down more serious issues as well. In the case of my last phone (galaxy s3), it simply didn't last long enough for me. I ended up buying a battery that was twice the physical size. It came with a bigger back to the phone. While this made it bulky, I had plenty of battery life to last a day.
Not sure if anyone had mentioned this, but I went through a situation with my Galaxy S3 a few years back and it turned out that the battery needed to be calibrated.
I downloaded an app and it required me to charge my phone to 100%, run the calibration app, completely discharge the battery and then charge it again to 100%.
This worked AMAZING!!! My phone would literally lie to me about the actual percent left. It would say 70% and then shut down in 5 minutes, because it was actually at 10%.
Even after this, I would calibrate it every so often, to keep the phone and battery communicating and functioning properly.
I use a group of apps by DU Group to maintain my phone and I find it is helpful with notiofying me to cooling my phone temperature or clean trash files for optimization. This app even has a setting to optimize the charge by charging in three different stages.
Might be worth checking out for some of you. Hope this helps, because battery issues are the most frustrating!
Also, batteries tend to lose charge quicker as they get older. That's why it's also good to get a phone with a replaceable battery.
The reason white is more efficient than black on LCD screens is that the LCD pixels are like little shutters that block or transmit light. Pixels that are energized block the light (black), the ones not energized let light through (white). So it takes more electricity to show black than it does to show white. Light output between the full brightness and full darkness will use a proportional amount.
@Darquin I think you have that backwards, black screen is more efficient than white screen
White is transparant, black is off
Hence lower consumption in general*
*there are some technologies where white uses less power, but from what I have seen they are usually in tv or pc.
@srlawren yeah that's why I mentioned other screens
I don't think any phones come with a "real" LCD these days, most are at least LED if not OLED or AMOLED
Cut & Pasted
An AMOLED doesn't have a backlight at all. Instead, each little sub-pixel is like a tiny red, blue, or green colored light. If the screen is instructed to display black, it doesn't need to block any light, it simply doesn't light up any of the little colored sub-pixels.
So theoretically, black pixels save you a lot of power because those pixels can be turned completely off. However, people sometimes make the mistake of thinking this is a function of brightness—that dark colors like gray are similarly efficient. There is a relationship between brightness and power, but to really save juice you need a true black (as defined by the #000000 hex value). Anything else, and the pixel is on.
@kav2001ctons of phones have IPS or LCD panels. In particular, all current and past iPhones. And lots of previous budget Android phones as LCD used to be cheaper than LED or AMOLED but that has changed in recent times.