[captain27]

Originally Posted by Nuggit

If you move your mouse cursor to the middle of the bottom of the screen, a few icons pop up. With for example a periscope, a map and some other icons that I cant remember right away.
The one to the furthest left, if you press that, some smaller icons appear, one of them is a propeller if I remember correctly... if you press that, another list of icons appear, one of them is a battery. If you click that, the batteries will charge! (It takes a fair share of time to recharge them).

Also note that you need to be either surfaced or have the snorkel lifted.

Thanks I will try it