In the Power Plant level
Take the first battery you come across and plug it into the terminal close by.
Walk through the Gate and walk to the left, you will see a small fan high in the wall. Jump on the ledge close by and tear it out. Take the fan and place it on the button close by.
Go back to the ledges we were just at and jump to the wall across from them. Follow the wall to the left and jump onto the conveyor belt. Then jump onto the platform that's holding the box. Grab the box and jump back to the conveyor then to the ground in the same room. Place the box on this second button.
Go back and get the battery from earlier. Bring it into the room we just opened with the box. Bring over the charger (the device on wheels) and charge the new battery. Plug in either battery to the gate. Lift the gate as far as you can. Bring the charger and stick it up against the gate.
In the next room, plug in the set of wires to the generator and the terminal. Pull the rip-cord on the generator 3 times to start it. Now walk through the gate to the next room.
Hop onto the forklift and drive it to the last room, around the generator and use it to lift the vertical gate even more. Grab the charger and put it directly under the gate to hold it in place when you move the forklift and unplug the battery. Now drive the forklift from the vertical gate back to the room it came from and lift up that rooms vertical gate with it.
Go back and get the two batteries and move them now to the room with the statue. Grab the long pair of wires from the generator room and take them also to the statue room.
Then make your way back to the room with the small fan and ledges. Climb on the ledges once more and climb up the wall they are directly next to. Once on top make your way to the 3 [coils?] on the roof. One of them is attached to the transmission tower in the statue room via cable. Jump and grab the cable to swing towards the statue and steal the battery. This will get you the 'Thief'
achievement if you don't already have it. Take the battery to the gate on the left side of the room.Bring the other batteries and the generator room wires here as well.
We'll name the batteries 1, 2, and 3, from left to right.
Plug in a blue wire to the blue sockets on the terminal and battery 3. Plug in a red wire in the red socket of battery 3 and to the blue socket on battery 2. Take a blue wire and plug it into the red socket on battery 2 and the blue socket on battery 1. Tak a long red wire and plug it into both the red sockets of battery 1 and the terminal, completing the loop, opening the door and awarding you the achievement!