Just 22hrs after charging my Galaxy Gear, it's already minutes away from switching off and needing a recharge.
I've read dozens of guides on how to extract as much life as possible from the tiny 312mAh battery, but few go into sufficient detail to help make informed decisions.
So, here's a list (in order of effectiveness, highest to lowest) of steps you can take to increase your battery life.
1) Upgrade to Tizen
Google's Android is great, but it was never designed for use on a smart watch.
If you haven't already done so, install Samsung Kies and connect your Gear. If there's an update available in your region, it'll prompt you to upgrade. Make sure your battery is 50% or greater before starting the upgrade.
2) Perform a factory reset
Even if you've just upgraded to Tizen, go through the recovery/reset process. This will completely wipe your device.
With the Gear switched on, press and hold the power button until it says "rebooting". Press the power button 5 times. You'll arrive at a menu with 3 options which you can scroll through by pressing the power button. Go to "recovery" and press & hold the power button for 3 seconds to select it. Follow the instructions and wait for it to reset.
3) Disable "Motion Wake"
With "Motion Wake" enabled, the Gear uses the gyroscope and accelerometer to detect and calculate your movements. Although only specific movements will cause the Gear to wake up, you may not realise that it's constantly "listening" to your movements which ultimately affects your battery life. I leave it enabled because I'm happy to lose some battery life for the benefit of not pressing the power button each time, but if you really want to optimize your battery life, disable this too.
4) Update Gear Manager and all dependencies
As a companion device, the Gear needs to be paired with a smartphone to work effectively. Each time it sends notifications or indeed any data at all, it devours the battery of both devices. The latest versions are much more efficient.
5) Disable "Auto Unlock"
Auto-unlock works by continually transmitting a signal to paired devices, letting them know that it's within range. Although useful, it's very power-hungry.
6) Use a black wallpaper
The Galaxy Gear uses an AMOLED screen. As opposed to LCD screens, each AMOLED pixel is illuminated individually. When your device needs to show a black pixel, it simply disables that pixel. With a black wallpaper, the vast majority of your screen is switched off. Tests have shown this can increase your battery life by as much as 20%.
7) Reduce your screen timeout time
It goes without saying, but the longer your screen is on, the less time your battery will last. The minimum time in Tizen is 10 seconds, with Android allowing just 7 seconds. If you have "Motion Wake" enabled, keep in mind that each time it wakes (intentionally or otherwise), this timeout value starts again.
8) Reduce your screen brightness & sound volume
If you must use "outdoor mode", use it sparingly. At full brightness, the Gear gobbles battery life. Use the absolute minimum you need to use it without straining your eyes. Also, keep the volume as low as possible.
With Tizen, a factory reset, motion wake enabled, the latest Gear Manager, auto unlock disabled, a black wallpaper, a 10 second screen timeout, a screen brightness of "3" and roughly 40 notifications per day, I managed just over 3 days of usable life. If you're a particularly heavy user, you should achieve 2 days quite easily.