There are a few different location settings in the vWork iPhone app which will have an impact on your battery life.
We have a step by step article on how to adjust these here.
The final setting is Automatic. This accuracy setting uses cellular tracking when the phone is running on battery power, but switches over to GPS tracking when the phone is plugged into an external power source like a laptop, wall charger or cigarette lighter charger. Automatic is the default setting and is strongly recommended to optimise battery performance.
The vWork iPhone application can track location in two different modes. The first is called Cellular Tracking and does not use GPS, it calculates it's location based on cell sites. This is not as accurate as GPS, but draws much less power. You can roughly expect to see what suburb the phone is in when using cellular tracking.
The second type of tracking (GPS) is far more accurate, right down to the location's street address. However, this draws much more power. If vWork is left running in GPS accuracy mode, you can expect battery life to only be a few hours. If you switch the accuracy setting from Automatic to GPS, ensure the phone is plugged into a wall or car charger as much as possible. If not, you will end up with a flat battery within a few hours.