The battery life on all of our iTouch smartwatches greatly depends on your personal usage
The above watches have a standby time of 30 days (our Slim is 20 days) and a working time of 5-7 days depending on your usage.
Also, if the watch is idle for more than a month, it may not be able to power on because the battery has fully drained. Plug in your watch into the charger. It should power up after a few minutes of charging.
We do suggest charging your watch by using a desktop/laptop computer to maximize battery life and charge capacity =)