Before getting ahead of ourselves, if you're unsure of how to charge the items, are you aware that the power armour itself is simply a base? I think it has a little storage, but will not do anything useful (including offering protection).
In order to add these things, you need a tinker table, and a number of components. When you open the table with the pieces of armour in your inventory, it will allow you to select each one and show the possible upgrades for them, including the required components.