Benjamin Newson Fixes a Keyboard's Battery Hunger — With a Lithium Pillow and USB Type-C Charging
Sick of swapping out AA batteries in a wireless keyboard, Newson decided to get with the times and add USB Type-C charging.
Electrical engineer Benjamin Newson has penned a guide to replacing the disposable AA batteries in an off-the-shelf wireless keyboard with a USB-rechargeable lithium pack in its place — putting an end to the dead-battery problem once and for all.
"My old wireless keyboard kept running out of batteries… so I decided to fix that," Newson writes of the project. "I modified my wireless keyboard to add a USB [Type]-C charging port, transforming it into a rechargeable setup instead of constantly swapping out batteries. Now it charges just like a modern device — simple, convenient, and no more dead batteries at the worst time."
It's common to find wireless keyboards and mice that use replaceable AA or AAA batteries rather than an integrated battery with charging system — and the approach offers some advantages beyond a simpler and cheaper bill of materials, too: when the batteries die they can easily be swapped out without waiting for anything to charge, and for those who want to do their bit for the environment you can use rechargeable batteries that charge outside the device.
Having an integrated battery with USB charging, though, is undeniably handy for those who don't keep a drawer filled with AA/AAA batteries ready to swap out — and doubly so if you can use the device while it's charging. Newson's mod is straightforward: the case is modified to take a TP4056 battery charging module, routed to a 3.7V 200mAh pillow-style lithium battery. Everything is small enough to squeeze into the case alongside the existing hardware, and is soldered to the keyboard's logic board to provide power in place of the usual batteries.
"Once all connections are soldered," Newson advises, "use some hot glue to secure the USB [Type]-C charging port in its location. Make sure the port is properly aligned so a charger can be easily plugged in without obstruction."
The project is documented in full in the video above and in Newson's Instructables post.