Introduction: How to Integrate Wires Into 3D-Prints to Build a 18650 Battery Charger
My goal was, to build a battery charger for 18650 Li-ion batteries. For this project, I designed a 3D-printable part where I can integrate the tp4065 charger board and the wires which connect to the battery terminals.
This method can be useful, for every 3D-print with integrated electronics.
You can also watch my Video about this Project:
Step 1: Material You Need
As charging circuit I use a tp4056 li-ion charger. This charging module is cheap and available as a protected version to prevent overcharging the battery.
TP4056 on Amazon: http://amzn.to/2fDOQ5Z
The charger which I build is capable to charger 18650 Li-ion batteries. I guess you have some because you are interested in this Instructable.
18650 Li-Ion Battery: http://amzn.to/2fEHoYv
What you need is a piece of wire. I recommend not to use litz wire but a wire with one solid copper pliable wire. It is easier to integrate into the 3D-print.
- Because it is a 3D-printing related project, you need a 3D-printer. (or a friend with a 3D-printer)
- For soldering your soldering iron.
- And for the wort with the wire side cutter, pliers, and cable stripper.
Step 2: Designing and Printing
You can download my 3D-model, print it and go to the next step. Here I will explain you my thought to my design.
My goal was, to create a well designed, and print in one part battery holder with integrated charger circuit.
I wanted to integrate all the wires into the 3D-print. First because of the nicer look, but also to avoid any failures from improper installed Wires wile later usage.
The designed features:
- The battery snaps into its place due to the flexibly designed bracket.
- The cutout enables an easy grabbing for removing the battery.
- The bore is to attach the charger to my solar panel (See the Instructables)
- The TP4056 charger circuit fits into the pocket on the side.
- Trough the opening the status LED's of the circuit are visible.
- To create a contact on the poles of the battery, there are two holes to thread the wire through.
- On the bottom and top side are grooves to install the wire.
- And for bringing the + pole wire to the bottom I designed a boring through the part.
- For routing the wires to the charger circuit there are holes towards the soldering pads of the TP4056 module.
Step 3: Integration of the Circuit and the Wires
Now, I explain to you how I integrated the wires into the 3D-print.
- First I soldered two wires to the tp4056 charging circuit.
- Then I insert the charger with the wires ahead into its designated pocket.
- The positive wire I route upwards through the long 2mm boring.
- Now the positive wire points out of the top, and the negative wile out of the bottom.
- The negative wire has to cross the positive wire according to the grooves in the bottom.
Step 4: Build the Pole Contacts With the Wire
Now we make the two pole contacts with the positive and negative wire to have a connection from the battery to the charger circuit.
- Both outstanding wires we can cut down to 5cm lengths.
- With the cable stripper, we remove the isolation from the outstanding wires.
- now we push the wire to one boring down,
- pull it with the pliers through,
- and push it through the other boring back
- and pull it tight with the pliers.
- The end can now be cut down again to a length which can be bent over and slowed into the groove.
With this method, you will get a good contact for the battery poles.
Step 5: Glue the Wires in Place and Test the Charger
I used hot glue to ingrain the wires into the grooves.
With a multimeter, I made a short test if the polarity is correct and everything works.
As you saw on some pictures, I'm able to use this charger with my tiny solar panel.
I hope you got some inspiration and please send me some comments from you projects where you used similar methods to integrate electronics into a project.
- The Charger has no mechanical protection against reversing the polarity of the battery.
- I recommend to only use 18650 Batteries with built-in protection circuit.