Giant 3D Printed Xbox One Controller Battery Pack

I made a dual 18650 battery pack a couple of months ago but it came out rather crude looking and while it did work it left a lot to be desired. Since then I came into owning a 3d printer and I thought it would be a fun idea to revisit this project with the intent of making a prettier battery pack using the magic of 3d printing.

The idea behind this project was to make a battery pack that could last for days or even weeks on one charge. With the use of two 3,000mah batteries in parallel for a total of 6,000mah that intent has come to fruition! You could use just one cell for a smaller profile but where's the fun in that? Since this project uses two cells its important to note that the individual cell voltages should be balanced before running them in parallel.

This project is to be done at your own risk as it deals with charging, discharging and handling 18650 cells. These cells pack a lot of power and you definitely don't want to underestimate them.

Yes, it looks ridiculous and adds weight but surprisingly it doesn't get in the way of normal use and after using nothing but this as a battery for a month or two I've grown to love the added weight.

Let's get started!

Supplies

3d printer or access to one

Assorted hardware for the case and terminals (I will give measurements for the hard ware used in the steps)

2 18650 cells

Charge controller for those cells

micro usb breakout board

JB weld plastic bonder

18650 battery contacts

soldering equipment

Step 1: Watch the Video If You Please :)

In this video I cover the build process.

Step 2: All the 3d Printed Bits Explained

This is designed in a few pieces: The battery holder, a lid for the holder, the cover door for the controller, a triangle and four small rectangles. The four small rectangles are for holding the contacts for the cells, the triangle is for holding a breakout micro USB port for charging and everything else is pretty straight forward. The pieces will be glued together during assembly while the lid will be screwed in place after assembly of the main parts,

I can't take credit for the battery door. I found it online and modified it for my uses in this project all credit for the door goes to the maker at https://www.thingiverse.com/thing:4538258 who made their own 18650 powered controller in a different manner.

Step 3: Creating the Battery Contacts

I found these contacts on Amazon and as they sit they won't work for my design. I admit that I designed the sled before knowing what contacts I wanted to use and now that I know which ones I want I could redesign the sled to make them more easier to use but I didn't want to waste the prints that were already made.

I decided to cut some 'teeth' into the contacts and fold them at a 90 degree angle so they stick out behind. From here we can place the contacts onto the squares and carefully heat them up using a clean soldering iron tip. This will cause the metal to sink into the plastic and after it cools its surprisingly secure. Then we can take these contacts and glue them into the sled. You can use epoxy for this as I did in my video but superglue works wonders on PLA. Make sure to place the contacts in a parallel configuration.

I'm sure some may be asking why I'm using contacts when the batteries could be permanently fixed via welding or soldering (not a recommended method) and the answer to that is I like having the option of swapping these cells out in the future if they go bad or if I come across better cells.

Step 4: Combining the Sled and Battery Door

The easiest way to combine the two pieces is to use a controller to hold the door while you you place a small amount of JB plastic weld and then the sled on top. I recommend rigging the controller up so its level while the epoxy sets. The use of an xbox one controller stereo adapter can help keep the sled level it sets. I messed around with the idea of printing this as a whole piece but didn't like the amount of supports that it would need.

Step 5: Soldering the Contacts to the Charge Controller

Once the two pieces are secured we can add a charge controller and start soldering some wires! You can use any charge controller that charges, discharges and has safety features but I am using a prototype one that I designed. I mounted mine in place using hot glue and drilled some holes through the sled to allow the wires to pass through. The contacts were soldered in parallel then routed through the sled to the charge controller. I could've added these holes in the design but I figured it would be easier to drill them out rather than figuring out exactly where they should be cut out in the design. I am still really new to 3d printing.

Step 6: Making the Output Contacts

The main reason I used the battery door I found on thingiverse is due to the creators awesome attention to detail. They mapped out exactly where they should place hardware on the door to contact the battery tabs in the controller.

Screws with the diameter of 2.5mm were threaded through the holes and a nut was used to secure them in place. From here we can use another nut to hold a wire in place. These wires will run to the respected charge controllers battery output. The screw heads will contact the battery tabs inside the controller and allow for a transfer of power. I plan on finding copper screws to replace these ones in the near future.

Since a fully charged 18650 cell reaches 4.2 volts some of you may be wondering if that's a problem for the Xbox One controller since it was designed to use two 1.5 volt double A batteries for a total input of 3 volts. I had this thought and decided to power a controller using my bench power supply set at 4.2 volts for several hours. During this time the controller functioned normally and no additional heat was recorded so I concluded that it isn't that much of a concern.

Step 7: Adding the Micro USB

As with other parts of this project I'm sure this could've been done better but........ I'm a newb. I superglued the USB breakout board to the triangle then superglued that triangle under the oversized rectangle cut out. From here the 5volt and ground contacts from the USB breakout can be soldered to the charge controllers input. The filament is just translucent enough to allow the status led to be seen through it.

Step 8: Let Finish This Beast!

Now we can slap some cells in and screw the lid into place! I used screws with a diameter of 2.5mm and a length of 6mm. The screws were able to force a thread in the plastic which is what I was hoping for. Now we charge this beast over night then game for days straight on one charge! I did the math and with these cells I calculated around 80 hours of straight runtime. Which is 2 weeks worth of playing uninterrupted! I haven't actually tested these numbers yet. I made two of these and always have one on deck to swap out.

That's it for this ible, I really hope you enjoyed and thank you so much for making it this far!