AA Battery to USB Adapter (with 3d Printed Parts)

We 3d printed a custom AA battery shape to augment battery-powered devices with USB power.

• Tinkercad
• Creality Ender 3
• PETG filament (but any will do)
• Old/broken USB power cord

We chose a custom battery shape over the battery included in Tinkercad because we will be adding wires that will make it a tighter fit in the battery box. This shape is 1mm shorter than the battery from the Tinkercad toolbox.

There are holes for wires. We will add them later.

We used Ultimaker Cura as the slicer, with standard settings for PETG filament on an Ender 3 printer.

Wiring the USB is pretty easy with help from this Instructable. Inside a USB cord, you can see we're interested in the red and black wires, which are 5V positive and negative/ground, respectively.

You'll want to strip the wire back at least as long as the battery so you can move them around. Then it's as simple as matching the red wire to the positive battery terminal, or the bumb at the end of the battery. The black wire goes to the negative terminal, or the flat end.

We pulled enough wire through the hole to bring the end back and form a loop. That's where we twisted it to ensure it stays put.

Here's what you need to know about USB power.

A USB port provides about 5volts. We looked at battery circuits in Tinkercad to compare the voltage of 2 different battery boxes - a 2-battery box, and a 4-battery box. You can see by these images a standard battery box with either 2 or 4 batteries does not provide 5V power.

Add your 3d-printed battery adapters to the battery box in the furthest spaces available to complete the circuit. But be aware you may be over-powering a 2-battery, 3V circuit. For most small DC motors, like a fan, it shouldn't matter.

Another factor to consider - be careful using UNPOWERED USB ports. If you draw too much power by connecting to the USB port on your phone, tablet, laptop, or computer, you could damage your device.

That's it. Other than those warnings, enjoy your battery operated devices without burning through batteries that might end up in a landfill.