The battery is 3000mAh, and device works with battery voltage above 2.9-3V. So after full charge let's say 0.9 of capacity is used = 2700mAh.
Current consumption while tracking is a little below 40mA, while in sleepmode below 1mA. 2700mAh / 40 mA = 67.5h of continuous tracking,
at least based on the calculations. Though I was not testing battery life this way, I was testing it together with sleepmodes to see if it lasts for a
couple of weeks under my car and it did. I have upgraded the battery from 1800mAh to 3000mAh since then and have not tested these yet.