I'm trying to get through the airlock at the beginning but every time I drag the dead battery from my inventory to the charger it drops to the floor.

Any ideas?

You don't drag the battery from your inventory. You use the charger by clicking the right mouse button. It will charge everything in your inventory that uses energy.

I was having a moment of brain-fade.

I was trying to charge it by right-clicking on place where the battery goes rather than on the charger to the right.

I'd even just been through the training.

Guess I'm just soooo excited that I'm able to play this again that my brain has melted. :D